CA1332514C - Process for agglomerating mineral ore concentrate utilizing emulsions of polymer binders or dry polymer binders - Google Patents

Abstract

This invention is a method for agglomerating mineral ore concentrate comprising the commingling of mineral ore concentrate with a binding amount of water soluble polymers, preferably poly(acrylamides). The polymer is applied to the mineral ore concentrate either (1) as a dispersion in a non-aqueous dispersion medium, such as a water-in-oil emulsion, or (2) as a dry powder. This invention is also a method of agglomerating mineral ore concentrate with flux material.

Description

`~

~13~2 D1~

A PROCESS FOR AGGLOMERATING MINERAL ORE CONCENTRATE
UTILIZING EMULSIONS OF POLYMER BI~DERS OR DRY
POLYME~ BINDERS
BACKGROUND OF THE INVENTION
l. Fleld Or the Inventlon Thls lnventlon relates generally to methods ror agglomeratlng or pelletlzlng mlneral ore concentrate.
More speclflcally, thls lnventlon relates to methods for agglomeratlng or pelletlzlng mlneral ore concentrate uslng water soluble, hlgh molecular welght polymer blnder system~ ln elther water-ln-oll emulslons or a~ a dry powder.

2. De~crlptlon Or the Prlor Art It is customary ln the mlnlng lndustry to agglomerate or pelletlze flnely ground mlneral ore concentrate 80 a8 to further facllltate the handling and shlpping Or the ore. Mlneral ore concentrates can lnclude lron oxldes, copper oxldes, barytes, lead and l~ zlnc sulfldes, and nlckel sulrldes. Agglomerates of coal dust and nonmetallc mlnerals used to make brlcks or ceramlcs are also rormed. Agglomerate rorms can lnclude pellets, brlquettes, and slnters.
Methods of pelletlzlng mlneral ore concentrate are ~requently used ln mlnlng operatlons w~ere the ore 18 a low grade lron ore. Examples Or low grade lron ores are ~,f ~ I *

-9 1 3 .~
- D-14,834 taconlte, hematlte, and magnetlte. Numerous other low grade ores exlst wherein pelletlzing Or the ground partlcles ls benerlclal to the handllng and shlpment Or the mlneral ore. Arter the mlneral ore has been mlned, lt 18 rrequently ground and screened to remove large partlcles whlch are recycled ror rurther grindlng.
Typlcally, an ore 18 psssed through a lO0 mesh (0.149mm) screen. The screened mlneral ore 18 known as a "concentrate".
For example, taconlte mlneral ore concentrate arter grlndlng and screenlng has an sverage molsture content Or between sbout 6 to about lO percent. The moisture content Or the mlneral ore concentrate can be selectlvely altered. The molsture content arfect~ the strength Or the pellets that are rormed later ln the process .
Arter screenlng, the mlneral ore concentrate 18 transported on a rlrst conveyor means to a balllng drum or another means ~or pelletlzlng mlneral ore concentrate. Prlor to enterlng the balllng drum, a blndlng agent 18 applled or mlxed lnto the mlneral ore concentrate. Commlngling the blndlng agent wlth the mineral ore concentrate occurs both on the con~eyor mean~ and ln the means for pelletlzlng. The blndlng agents hold the mlneral ore concentrate together as ~1332~1~
- D-14,834 pellets untll arter rlrlng.
Balllng drums are apparatu~es comprlslng long cyllndrlcal drums whlch are lncllned and rotated. The mlneral ore concentrate 18 slmultaneously rotated about the balllng drum's clrcumference and rolled ln a downward dlrectlon through the drum. In thls manner the mlneral ore concentrate 18 rolled and tumbled together to rorm roughly spherlcal-shaped pellets. As the pellets grow ln slze and welght they travel down the lncllne Or the drum and pass through the ex~t Or the drum at whlch polnt they are dropped onto a second conveyor means whlch transports them to a klln ror rlrlng. Inslde the balllng drum, dlrrerent ractors lnrluence the mechanlsms Or unlon Or the mlneral ore concentrate. These ractors lnclude the molsture content Or the ore, the shape and average slze Or the mlneral ore pa-tlcle~, and the dlstrlbutlon Or concentrate partlcles by slze. Other propertles Or the mlneral ore concentrate that lnfluence the pelletlzlng operatlon lnclude the mlneral ore's ~ettablllty and chemlcal characterlstlcs. The characterl~tlcs Or the equlpment used, such as lts si~e and speed Or rotatlon, can erfect the er~lclency Or the pelletlzlng operatlon. The nature and guantlty Or the agglo~eratlng or blndlng agent used ln the concentrate 1~ also a ractor that determlnes part ~ ~;

Q 1~ 3 ~ D 14, 834 Or the errlclency Or the pelletlzlng operatlon.
The rormatlon Or agglomerates beglns wlth the lnterfaclal rorces whlch have a coheslve erfect between partlcles Or mlneral ore concentrate. These lnclude S caplllary rorces developed ln llquld rldges between the partlcle surraces. Numerous partlcles adhere to one another and rorm small pellets. The contlnued rolllng o' the small pellets wlthln the balllng drum causes more partlcles to come lnto contact wlth one another and adhere to each other by the caplllary tenslon and compresslve stress. These rorces cause the unlon of partlcles ln small pellets to grow ln much the same manner as a snowball grows as lt 18 rolled.
Arter the balling drum operatlon, the pellets are formed, but they are stlll wet. These pellets are commonly known as "green pellets" though taconlte pellets, ror example, are usually black ln color. Green pellets usually have a denslty Or about 130 lb/ft3 ln slzes between about l/2 lnch and about 3/8 Or an lnch.
The green pellets are transported to a klln and heated in stages to an end temperature Or approxlmately 2800F.
Arter heatlng, rlred pellets are extremely hard and reslst cracklng upon belng dropped and resist crushlng when compressed.
Two standard tests are used to measure the strength ~,.

~ ~L 3 r~
~- ~ D-14,834 Or pellets whether the pellets are green pellets or flred pellets. These tests are the "drop" test and the "compresslon" test. The drop test requlres dropplng a random sampllng Or pellets a dlstance, usually sbout 18 lnches or less, a number o~ tlmes untll the pellets crack. The number o~ drops to crack each pellet 18 recorded and averaged. Compre~slon strength ls measured by compresslng or applylng pressure to a random sampllng Or pellets untll the pellets crumble. The pounds OI
rorce requlred to crush the pellets 18 recorded and averaged. These two tests are used to measure the strength Or both wet and ~lred pellets. The drop and compresslve test measurements are lmportant because pellets, proceedlng through the balllng drum and subsequent conveyor belts, experlence rrequent drops as well as compresslve rorces rrom the welght Or other pellets travellng on top Or them.
Thermal shock reslstance 18 a factor whlch must be taken lnto conslderatlon ln any process ror agglomeratlng mlneral ore concentrate. Increases ln a pellet's thermal shock resl~tance lmprove that pellet's ablllty to reslst lnternal pressures created by the sudden evaporatlon Or water when the pellet 18 heated ln a klln. If the pellet has numerous pores through whlch the water vapor can escape thermal shock reslstance 18 ., .

01~ 3 ~
D-14,834 lmproved. Ir the sur~ace Or the pellet is smooth and contlnuous wlthout pores the pellet has an lncreased tendency to shatter upon rapld heatlng. Thls causes a concurrent lncrease ln the amount Or "flnes" or coarse partlcles in the pelletlzed mlneral ore. A blnder whlch lncreases the pores rormed ln a pellet lmproves that pellet's ablllty to reslst thermal shock.
Bentonlte ls used as a blndlng agent ln the pelletlzlng operatlons ror taconite ore concentrate.
Bentonlte produces a hlgh strenBth pellet havlng an acceptable drop strength, compresslve strength, and thermal shock re~lstance. Bentonlte has the dlsadvantage Or lncreaslng the slllca content Or the pellets that are ~ormed. Slllca decreases the ef~lclency Or blast rurnace operatlons used ln smeltlng Or the ore. For thls reason bentonlte requlres a hlgher energy expendlture than do organlc blnders.
Other blndlng agents have proven to be better blnders than bentonlte. These agents lnclude organlc binders such as poly(acrylamlde), polymethacrylamlde, carboxymethylcellulose, hydroxyethylcellulose, carboxyhydroxyethylcellulose, poly(ethylene oxlde), guar gum, and others. The use Or organlc blnders ln mlneral ore pelletlzlng operatlons 18 deslrable over the use Or bentonlte because organlc blnders do not lncrease the ~ :v K ~

~1332~1~
D-14,834 slllca content of pellets and they lmprove the thermal shock reslstance Or the pellets. Organlc blnders burn durlng pellet rlrlng operatlons and cause an lncrease ln the poroslty Or the pellets. Flrlng condltlons can be , modlrled to improve rlred pellets' mechanlcal propertle~
ror organlc blnder systems.
Some organlc blnders used ln mlneral ore pelletlzlng operation~ are dlssolved ln an aqueous solutlon whlch 18 sprayed onto the mlneral ore concentrate prlor to enterlng the balllng drums. Thls appllcatlon Or an aqueous ~olutlon lncreases the molsture content above the natural or lnherent molsture content Or the mlneral ore concentrate whlch requlres a Breater energy expendlture durlng the rlrlng operatlon Or the pellets. Thls lncreased molsture content also causes an lncreased llkellhood Or shatterlng due to - lnadequate thermal shock resl~tance durlng rlrlng.
Pellet rormatlon 18 lmproYed wlth the use Or organlc blnders, but the drop strength and compresslon strength Or the pellet are rrequently below that deslred or achleved wlth bentonlte.
Other blnder~ commonly used ror agglomeratlng mlneral ore concentrate lnclude a mlxture Or bentonlte, clay and a soap, Portland cement, sodium slllcate, and a mlxture Or an alkall salt Or carboxymethylcellulose and 2 .~ 1 ~

D-14,834 an alkall metal salt. The agglomerates made rrom these blndlng agents rrequently encounter the problems descrlbed above Or lnsurrlclent pellet strength or lnsurrlclent poroslty ror the rapld release Or steam S durlng lnduratlon wlth heat. Addltlonally, these ~- blndlng agents are usually applled to a mlneral ore concentrate ln aqueous carrler solutlons o- as dry powders. Aqueous carrler solutlons lncrease the amount Or energy requlred to rlre the pellets and lncrease the lncldence Or pellet shatterlng due to lnadequate thermal ~hock reslstance.
U.S. Patent Number 3,893,847 to Derrlck dlscloses a blnder and method ror agglomeratlng mlneral ore concentrate. The blnder used ls a hlgh molecular welght, substantlally stralght chaln water soluble polymer. Thls polymer ls used ln an aqueous solutlon.
The polymers dlsclosed 8S userul wlth the Derrlck lnventlon lnclude copolymers Or acrylamlde as well as other polymers. The Derrlck lnventlon clalms the use Or polymers ln an "aqueous" solutlon. The use Or water as a carrler solutlon ror the blndlng agents lncreases the molsture Or the agglomerates or pellets that are rormed.
The hlgher molsture content lncreases the energy requlred to rlre the pellets and can lncrease the rate Or destructlon Or the pellets durlng lnduratlon due to :

~ ~ 3 ~ 2 ~ 1 1 D-14,834 the rapld release of steam through the agglomerate.
The lndustry ls lacklng a method ror sgglomeratlng mlneral ore concentrate utlllzlng low water content non-bentonlte blnder systems, such aQ water soluble, hlgh molecular welght polymer blnder systems ln water-ln-oll emulslons or dry powders. Thls lnventlon provldes pellets formed from the mlneral ore concentrate of hlgh mechanlcal strength propertles.

SUMMARY OF THE INVENTION
Thls lnventlon is a method for agglomeratlng a particulate materlal such as a mineral ore concentrate comprlslng the commlngllng Or mlneral ore concentrate with 8 blndlng amount Or water soluble, hlgh molecular welght polymers. The polymers are adapted to be selectlvely usable in at least one o~ either Or two condltlons Or use. In a rirst condltion Or use the polymers are applled to the mlneral ore concentrate as a dry powder. In a second condltlon of use the polymers are applied to the mineral ore concentrate in a water-in-oil emulsion.
This inventlon also includes a method comprising the commlngllng Or dry poly(acrylamlde) ba8ed polymer onto mlneral ore concentrate whereln the lnherent or added moisture content Or the mlneral ore concentrate is ., .

2 ~J l ~
D-14,834 su~lclent to actlvate the poly(~crylamlde) based polymer to ~orm pellets of the mlneral ore.
Thls lnventlon 18 partlcularly deslrable when used wlth an lron ore concentrate and can al~o lnclude the appllcatlon Or an lnorganlc salt ~uch as sodium carbonate, calclum carbonate, sodlum chlorlde, sodlum metaphosphate and mlxtures Or the~e ln conJunctlon wlth the polymer. The lnorganlc salt can be applled as a powder or an aqueous solutlon.

DETAILED DESCRIPTION OF THE INVENTION
Thls lnventlon 18 a method ror agglomeratlng partlculate materlal such as a mlneral ore concentrate uslng water soluble, hlgh molecular welght polymer~ in an amount surrlclent to blnd the mlneral ore concentrate. The polymers are applled to the partlculate materlal ln at least one Or elther a water-ln-oll emulslon sy~tem or a dry powder sy~tem.
The appllcatlon Or the polymers to a mlneral ore concentrate can be ln conJunctlon wlth an lnorganlc salt or mlxtures Or lnorganlc salts applled as powders or ln aqueous solutlons. The polymers and lnorganlc salt8 are commlngled wlth the mlneral ore concentrate.
Thls composltlon then enters a 8tandard means ror pelletlzlng or a balllng drum. The means ~or f , .

Q 1~ 3 2 ~ 1 D-14, 834 pelletizlng further commlngles the lngredlents and rorms wet or "green" pellets. The pellets are then trans~erred or conveyed to a furnace or klln where they are lndurated by heat at temperatures above about 1800F
and more prererably at about 2800F. A~ter lnduratlon, the pellets are ready ~or shlpplng or ~urther processlng ln a smeltlng operatlon such as a blast furnace.
Sultable polymers use~ul ln thls lnventlon lnclude water soluble homopolymers, copolymers, terpolymers, and tetrapolymers. In a water-ln-oll emulslon system the selected polymer ls produced by polymerizlng its monomerlc water-~ln-oll emulslon precurqor. Sultable polymers can be anlonlc, catlonlc, amphoterlc, or nonlonlc. It ls deslrable ln thls lnventlon to use polymers o~ hlgh molecular welght as characterlzed by a hlgh lntrlnslc vlscoslty. Thls lnventlon 18 not llmlted to polymers Or hlgh lntrlnslc vlsco~lty.
Polymers sultable for use wlth thls lnventlon, whether used ln water-ln-oll emul~lon systems or ln dry powder systems, are partlcularly deslrable when they are Or a hlgh molecular welght. The partlcular molecular welght Or a polymer 18 not llmltlng upon thls lnventlon.
Sultable polymers lnclude synthetlc vlnyl polymers and other polymers as dlstlngulshed rrom derlvatlves Or natural celluloslc product~ auch as "~

~ 1 3 3 2 .~ 1 ~
D-14,834 carboxymethylcellulose, hydroxyethylcellulose, and other cellulose derlvatives.
Useful measurements of a polymer' 8 average molecular weight are determlned by either the polymer's lntrlnslc vlscoslty or reduced vlscoslty. In general, polymers of hlgh lntrinslc vlscoslty or hlgh reduced vlscoslty have a hlgh molecular welght. An lntrinsic viscoslty ls a more accurate determlnatlon of a polymer's average molecular welght than ls a reduced vlscoslty measurement. A polymer's ablllty to form pellets of mlneral ore concentrate ls lncreased as the polymer's intrlnslc vlscoslty or reduced vlscoslty ls lncreased. The most deslrable polymers used ln the process of thls invention have an lntrlnslc vlscoslty of from about 0.5 t~ about 40, preferably from about 2 to about 35 and most preferably from about 4 to about 30 dl/g as measured ln a one normal (N) aqueous sodlum chloride solutlon at 25C.
- Water soluble polymers lnclude, among others, 20 ` poly(acrylamlde) based polymers and those polymers whlch polymerlze upon addltlon of vlnyl or-acryllc monomers in solutlon wlth a free radlcal. Typlcally, such polymers ~1~?92~1~
D-14,834 have lonlc functlonal groups such as carboxyl, sulfamlde, or quaternary ammonlum groups. Sultable polymers can be derlved from ethylenlcally unsaturated monomers lncluding acrylamide, acryllc acld, and methylacrylamide. Alkall metal or ammonlum salts of these polymers can also be useful.
Deslrable polymers for use ln this lnvention are preferably of the following general formula:

` R2 ~ 1 ? ~ 2 S l ~
D-14,834 whereln R, Rl and R3 are lndependently hydrogen or methyl, R2+ 18 an alkall metal lon, ~uch as Na+ or K+, R4 1~ elther (l) -OR5 whereln R5 i~ an alkyl group havlng up to 5 carbon atoms;

(2) i~-- O--R 6 whereln R6 18 an alkyl group havlng up to 8 carbon atoms;

o (3) o Il - O C R

whereln R7 1~ elther methyl or ethyl;

(4) phenyl;
(5) substltuted phenyl;
lS (6) -CN; or r 01.~32 ~l`;i D-14,834 (7) ; and whereln (a) is from 0 to about 90, preferably from about 30 to about 60 percent, (b) 18 from 0 to about 90, preferably from about 30 to about 60 percent, (c) ls from about 0 to about 20 with the provlso that (a)+(b)+(c) equal 100 percent, and (d) ls an integer of from about 1,000 to about 500,000.

~1332~
D-14, 834 Under certaln condltlons, the al~oxy or acyloxy groups ln the polymer can be partlally hydrolyzed to the correspondlng alcohol group and yleld a tetrapolymer of the followlng general formula:

r CH2~ c H2--c--~H2--c l , ICHO 1-- l R 4 OH

_ a ~ R2+~ b d ~l~32~
D-14,834 wherein R, Rl, R2+, R3, a, b, and d are as prevlously deflned, R4 ls -OR5 or O
-O- -R7 whereln R5 and R7 as deflned prevlously, c is from about 0.2 to about 20 percent, and e is from about 0.1 to less than about 20 percent.
The preferred copolymers are of the following formula:

~CH2 C; I~H2 C
l J~
d D-14,834 whereln R2+ ls an alkall metal ion, such as Na+ or K+, and r 1~ rrom 5 to about 90, preferably from about 30 to about 60 percent, g ls rrom 5 to about 90, prererably rrom about 30 to about 60 percent wlth the provlso that S (f)+(g) equal lO0 percent, and (d) ls an lnteger Or rrom about l,000 to about 500,000.
The prererred terpolymers are Or the rollowlng rormula:

~CH2 C ~ ~H2 C--. . CH2 C--_ 7-o ~c=o 1 L NH2 i ~ ~2 ~ ~ l ~ h ., ~ ~ 3 D-14,834 whereln R2l 18 Na~ or K+, R7 18 methyl, ethyl, or butyl and f ls rrom about 5 to about 90, prererably rrom about 30 to about 60 percent, g 18 rrom about 5 to 90, prererably rrom about 30 to 60 percent, h ls rrom about 0.2 to about 20, wlth the provlso that (r)+(g)~(h) equal 100 percent and d 18 as prevlously deflned.
The preferred tetrapolymers are of the rollowlng rormula:

;~CH2--C ~ ~C~'2--C ~ ' ~CH2 C--~CH2--C

~ 2Jf¦ ~ l ~ h~e OH e ln Rl, R2+, R3~ R7~ f, g, ~, d, and e are a8 prevlously deflned.

.7 ~

~ ~13~514 D-14,834 Other deslrable water soluble polymers ror use wlth thls lnventlon lnclude those derlved from homopolymerlzatlon and lnterpolymerlzatlon of one or more Or the rollowlng water soluble monomers: acryllc and methacryllc acld; acryllc and methacryllc acld salts Or the rormula CH2 C . C - O - Rg whereln R8 ls a hydrogen atom or a methyl group and Rg ls a hydrogen atom, an alkall metal atom (e.g., sodlum, potasslum), an ammonlum group, an organoammonlum group (Rlo)(Rll)(R12) NH+ (where Rlo, Rl and R12 are lndependently selected from a hydrogen atom, and an alkyl group havlng rrom l~to 18 carbon atoms (lt may be necessary to control the number and length Or long-chaln alkyl groups to a~sure that the monomer ls water soluble), such as 1 to 3 carbon atoms, an aryl group, such as a benzyl group, or a hydroxyalkyl group havlng rrom 1 to 3 carbon atoms, such as trlethanolamlne, or mlxtures thereof ; acrylamide and met~acrylamlde and derlvatlves lncludlng acrylamldo- and methacrylamldo monomers Or the formula:

~, r O 1 3 3 2 ~ 1 4 D-14,834 ~ 21 s~ -CH2 . C - \Rl~

whereln R13 1~ a hydrogen atom or a methyl group;
whereln R14 1~ a hydrogen atom, a methyl group or an ethyl group; whereln R15 ls a hydrogen atom, a methyl group, an ethyl group or -R16-S03X, whereln R16 ls a dlvalent hydrocarbon group alkylene, phenylene, or cycloalkylene havlng from 1 to 13 carbon atoms, preferably an alkylene group havlng from 2 to 8 carbon atoms, a cycloalkylene group havlng from 6 to 8 carbon atoms, or phenylene, most preferably -C(CH3)2-CH2---CH2CH2 ' ~

-CH(CH3)-CH2-, ~ and ~ CH3 X ls a monovalent catlon such as a hydrogen atom, an alkall metal atom (e.g., sodlum or potasslum), an ammonlum group, an organoammonlum group of the formula (R17) (R18) (R19) NH+ whereln R17, R18, Rlg are lndependently selected from a hydrogen atom, an alkyl ` 01332511 D-14,834 ~ 22 group havlng from 1 to 18 carbon atoms (lt may be necessary to control the number and length Or long-chain alkyl groups to assure that the monomer 18 water soluble) such as 1 to 3 carbon atoms, an a.yl group such as a phenyl or benzyl group, or a hydroxyalkyl group havlng rrom 1 to 3 carbon atoms ~uch as trlethanolamlne, or mlxtures thereor, and the llke. Speclrlc examples Or water-soluble monomers whlch can be homopolymerlzed or lnterpolymerlzed and userul ln the process of thls lnventlon are acrylamldo- and methacrylamldo- sul~onlc aclds snd sulronates such as 2-acrylamldo-2-methylpropanesulronlc acld (avallable rrom the Lubrlzol Corporatlon under lts tradename, and herelnafter rererred to as, AMPS), sodlum AMPS, ammonlum AMPS, organoammonlum AMPS. These polymers can be efrectlve blndlng agents rOr mlneral ore concentrates ln about the same concentratlons or blndlng amounts used for ot~er polyacrylamlde based polymer blnders.
These water soluble monomers can be lnterpolymerlzed wlth a mlnor amount (l.e., less than about 20 mole percent, prererably less than about 10 mole percent, based on the total monomer~ red to the reactlon) Or one or more hydrophoblc vlnyl monomers.
For example, vlnyl monomers Or the rormula D-14,834 whereln R20 1s a hydrogen atom or a methyl group and R21 is - 0 - C - R22, a halogen atom (e.g., chlorlne), -0-R23~ ~ R24 or _11_OR25- whereln R25 ls an alkyl group, an sryl group or an aralkyl group havlng from l to 18 carbon atoms, whereln R22 18 an alkyl group havlng from 1 to 8 carbon ato~s, R23 is an alkyl group havlng from 1 to 6 carbon atoms, preferab-ly 2-4 carbon atoms, R24 ls a hydrogen atom, a methyl group, an ethyl group, or a halogen atom (e.g., chlorlne), preferably a hydrogen atom or a methyl group, wlth the provlso that R20 ls preferably a hydrogen atom when R22 ls an alkyl group. Speclflc examples of sultable copolymerizable hydrophoblc vlnyl monomers are alkyl esters of acryllc and methacryllc aclds such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, lsobutyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, etc.; vlnyl esters such as vlnyl acetate, vlnyl proplonate, vlnyl butyrate, etc.; vlnylbenzenes such as styrene, alpha-methyl styrene, vlnyl toluene; vlnyl ethers ~uch 01332~1~
D-14,834 as propyl vinyl ether, butyl vinyl ether, isobutyl vinyl ether, methyl vinyl ether, ethyl vinyl ether, etc.;
vinyl halides such as vinyl chloride, vinylidene chloride, etc.; and the like.
The preferred water soluble monomers of these water soluble polymers are acrylamide, AMPS and sodlum AMPS, sodium acrylate,~ and ammonium acrylate. The preferred -hydrophobic monomers are vinyl acetate, ethyl acrylate, styrene and methyl methacrylate.

0133251~
D-14,834 Examples of sultable polymers for use wlth thls lnvention ln water-ln-oll emulslons are llsted in Table I. This table provldes a representatlve llsting of sultable polymers for use ln the water-ln-oil emulslons, but does not encompass every suitable polymer or limit the polymers that can be used with this lnvention.

26 D-14,834 TABLE I
Poly(acrylamlde) Emulslonsl Mole S Intrlnslc S
Anionlc Copolymers PAM/Na Acrylate Vl~coslty Sollds 85/15 16.2 30 76/24 17.3 30 59/41 20.0 30 Catlonlc Copolymers PAM/Slpomer Q5_802 PAM/N-decyl Nonlonic Copolymers Acrylamide 99/1 5.8 PAM/NaA/Vinyl Anlonlc Terpolymers Acetate 47.5/47.6/4.9 10.8 30 23.0 29.5 80/15/5 RV ~17.5 30 PAM/NaAMPS/Vinyl Acetate 87/12/1 10.0 1 abbre~latlons: PAM: poly(acrylamlde); NaA: sodlum acrylate; NaAMPS: sodlum salt Or 2-acrylamido-2-methyl-propane~ulfonlc acld.
2 Slpomer Q5-80 18 a catlonlc compound Or dlmethylamlnoethylmethacrylate/dlmethyl sulrate quaternary salt.

3 Reduced ~lscoslty.

01332~1~
D-14,834 A second class of polymers lnclude~ those polymers used wlth this inventlon in dry powder form. These polymers must be water soluble, but do not necessarlly lend themselves to the formatlon of water-ln-oll emulslons. Typlcally, polymers whlch form water-ln-oll emulslons are also useful wlth the invented method as dry powder. Table II represents a listing of polymers which are desirable for use with this lnvention as powders. The powders listed in Table II do not encompass all polymers which can be used as powders in this invention.

01332~14 D-14,834 TABLE II
Poly(acrylamide) Powders Nonlonlc Rhone Poulenc AD-lOl (intrinsic vl~cosity 15.4dl/g) Approximate mole %
Anionic . PAM/NaA
Percol 7252 89/11 Percol 726 - 77/23 1 AD-10 is a poly(acrylamide) powder sold by Rhone Poulenc, 52 Vanderbllt Avenue, New York, NY.
2 Percol products have been analyzed to be copolymers contalnlng the approximate mole % of PAM and NaA glven in Table II and are sold by Allied Colloids of Fairfleld, New Jersey.

\

013~2514 D-14,834 Inorganic salts are optionally added to the mineral ore concentrate before balling operations primarily to increase the strength of wet pellets (green drop strength) or dry pellets (dry crush strength). Inorganic salts can be added either before, after, or during the addition of the dry or .
emulsified polymer. Polymers alone improve the dry compression strength of pellets, but not to the same degree as an inorganic salt. For this reason, desirable embodiments of this invention include the addition of an inorganic salt, however, this addition is not considered limiting upon this invention. Similarly, neither the inorganic salt selected nor the method of addition is not limiting upon this invention. For purposes of this invention the term "polymer binder system" can include a water soluble, high molecular weight polymer in a water-in-oil emulsion system, powder system or as hereinafter supplementally described regardless of whether the system includes, or is used with or without inorganic salt powders or solutions.
Inorganic salts suitable for use in this invention include alkali and alkali metal salts of carbonates, halides, or phosphates. Specific examples of inorganic salts include sodium carbonate (NaCO3), calcium carbonate (CaCO3, i.e., limestone), sodium metaphosphate (NaPO3)n where n is 2 or more, sodium chloride (NaCl), or as hereinafter supplementally disclosed, and mixtures of these. Other inorganic salts can be added to improve pellet compression strength. Additionally, inorganic ~' .

D-14,834 3o salts can be added ln mlxtures wlth one another as powders or ln solutlons. As the concentratlon o~
lnorganlc salt increases ln the mlneral ore concentrate, the compression strength of the resultlng pellets ls lncreased.
Sodlum carbonate 18 an lnorganlc salt that achleves good results ~or lmprovlng the compre~sion strength of pellets. Sodlum carbonate 18 most errectlve, when used wlth elther the dry or emulslfled polymer, ln an amount o~ at least 2 percent and preferably greater than 25 percent, calculated on the total welght Or the added lnorganlc salt and actlve polymer. Preferably the concentratlon Or sodlum carbonate as a percent Or the welght Or the polymer binder system varles from about 25 percent to about 95 percent. More prererably, sodlum carbonate 18 wlthln the range o~ about 30 percent to about 90 percent wlth the most optlmum range between about 50 percent to about 90 percent calculated on the total welght Or the mlxture of sodlum carbonate and the polymer.

The lnvertlble water-ln-oll emulslon system used ln thls lnventlon 18 a suspenslon Or droplets comprl6ed of both water soluble, hlgh molecular welght polymers and water ~n a hydrophoblc sub~tance. Examples Or sultable emulslon systems and methods to rorm sultsble cmulslons O 1 3 3 2 ~ 1 4 D-14,834 are found ln U.S. Patent Number 4,485,209 to Fan et al.
and U.S. Patent Number 4,452,940 to Rosen et al. each of whlch are bereln lncorporated by rererence.
Desirable hydrophoblc llqulds used ln these emulslon ~ystems are lsopararrln$c hydrocarbons. A
sultable lsopararrlnlc hydrocarbon ls that sold by the Exxon Corporatlon known as Isopar M. Other sultable hydrophoblc llqulds ror use as the external phase ln an emulsion system lnclude benzene, xylene, toluene, mlneral 0118, kerosenes, petroleum, pararrlnlc hydrocarbons, and mlxtures Or these.
In the mo~t deslrable embodlments Or thls lnventlon, whlch lnclude a polymer bindlng aBent ln a water-ln-oll emulslon, two surractants are used to rorm the emulslon. A rlr~t sur~actant 18 used to form the water-ln-oll emulslon system. Arter the water-ln-oll emulslon system 18 rormed, a second surractant ls added.
The second surractant 18 a water soluble invertlng surractant whlch, we belleve, permlts the lnver~lon Or the water-ln-oll emulslon to an oll-ln-water emulslon upon contact wlth the lnherent or added molsture present ln the mlneral ore concentrate. Upon lnverslon Or the water-ln-oll emulslon the polymer 18 rorced out Or the lnternal aqueous phase and made a~allable to the surrace Or the mlneral ore concentrate. Thls release Or the 0133251~
D-14,834 polymer onto the sur~ace Or the mlneral ore concentrate allows ~or rapld commlngllng o~ the polymer wlth the mlneral ore concentrate. Emulslons that do not contaln lnvertlng surfactants can be used wlth thls lnventlon.
The surractants sultable ror use ln rormlng emulslons Or thls inventlon are usually oll-soluble havlng a Hydrophlle-Llpophlle Balance (HLB) value o~
~rom about 1 to about 10 and preferably rrom about 2 to about 6. These surractants are normally rererred to as water-ln-oll type surractants. Sultable surractants lnclude the acld esters such as sorbltan monolaurate, sorbltan mono~tearate, sorbltan monooleate, sorbltan trloleate, mono and dlglycerldes, such as mono and dlglycerldes obtalned rrom the glycerolysls Or edlble rats, polyoxyethylenated ratty acld esters, such as polyoxyethylenated (4) sorbltan monosterate, polyoxyethylenated llnear alcohol, such a8 Tergltol 15-S-3 and Tergitol-25-L-3 supplled by the Unlon Carblde Corporatlon, polyoxyethylene sorbltol esters, such a~
polyoxyethylene sorbltal beeswax derlvatlve, polyoxyethylenated alcohols such a~ polyoxyethylenated (2) cetgl ether, and the llke.
Water-~oluble lnvertlng surractants ~hich csn be used lnclude polyoxyethylene alkyl phenol, 2~ polyoxyethylene (10 mole) cetyl ether, polyoxyethylene ~ , .

D-14,834 alkyl-aryl ether, quaternary ammonlum derivatlves, potasslum oleate, N-cetyl N-ethyl morphollnlum ethosulfate, sodlum lauryl sulfate, condensatlon products of hlgher fatty alcohols wlth ethylene oxide, such as the reactlon product of oleyl alcohol wlth lO
ethylene oxlde unlts; condensatlon products of alkylphenols and ethylene oxlde, such as the reactlon products of isooctylphenol wlth 12 ethylene oxlde unlts;
condensatlon products of hlgher fatty acld amlnes wlth five, or more, ethylene oxlde unlts; ethylene oxide condensatlon products of polyhydrlc alcohol partial hlgher fatty esters, and thelr lnner anhydrldes (mannltol-anhydrlde, called Mannltan, and sorbltol-anhydrlde, called Sorbltan). The preferred surfactants are ethoxylated nonyl phenols, ethoxylated nonyl phenol formaldehyde reslns, and the llke.
The lnvertlng surfactant ls used ln amounts of from about 0.1 to about 20, preferably from about l to about lO parts per one hundred parts of the polymer.
The mlxture of both the aqueous phase and the oll phase of the emulslons used ln thls lnvention can contain about 20 to about 50 and preferably from about 22 to about 42 percent welght of the hydrophoblc llquid and the hydrophoblc monomers, based upon the total welght of the compositlon.

0133251~
D-14,834 The aqueous solution used to form the emulsion systems of this invention can contaln a mlxture of water soluble monomers. These monomers have a water solubility of at least 5 welght percent and lnclude acrylamlde, methacrylamlde, acryllc acid, methacrylic acid, and their alkall metal salts, aminoalkyl acrylate, aminoalkyl methacrylate, dialkylaminoalkyl acrylate, dialkylamino methacrylate and their quaternized salts with dimethyl sulfate or methyl chloride, vlnyl benzyl dimethyl ammonlum chlorlde, alkali metal and ammonium salts of 2-sulfoethylacrylate, alkali metal and ammonium salts of vinyl benzyl sulfonates, maleic anhydride, 2-acrylamide-2-methylpropanesulfonic acld, and the llke.
The preferred monomers are acrylamide, acrylic acld, and sodlum salt of 2-acrylamido-2-methylpropanesulfonlc acld.
If acryllc acld i8 used as a monomer lt ls reacted with a base, preferably w1th an equivalent amount of base, such as sodlum hydrox-ide, so that the sodlum acrylate solution has a pH of from about 5.0 to about 10.0, preferably from about 6.5 to about 8.5, dependlng on the type and amount of base employed. Thls solutlon ls comblned wlth another water soluble monomer, such as acrylamlde, and then wlth water to form the aqueous phase.

D-14,834 Hydrophoblc monomers which can be userul in formlng the emulslon sy~tems of thls lnventlon lnclude one or more Or vlnyl ester~ such a8 vlnyl acetate, alkyl acrylates such as ethylacrylate, alkyl methacrylates such as methacrylate, vlnyl ethers such a~ butylvlnyl ether, acrylonltrlle, styrene and lts derlvatlves such as alpha-methylstryrene, N-vlnyl carbazole, and the llke.
Approprlate reactor~ and cataly~ts are also used wlth thls lnventlon. These compounds can vary.
Examples Or sultable reactors and catalysts can be round ln the Fan and Ro~en patents ldentl~led above.
Emulslons used ln thls lnventlon are made by any sultable method. A deslrable method ror maklng emulslons ls dlsclosed ln U.S. Patent Number 4,485,209 to Fan. Thls lnventlon 18 not llmlted to a partlcular emulslon or method ror produclng an emulslon.
An advantage to the use Or water-ln-oll emulslons ln the rormatlon Or pellets 18 that the amount of water added to the mlneral ore concentrate 18 greatly reduced rrom that requlred to dellver polymers ln aqueous solutlons, thus resultlng ln an energy savlngs upon rlrlng Or the pellets. Also, the hydrophoblc llquld or oll ln the lnverted water-ln-oll emulslon system 18 2~ consumed durlng the rlrlng operatlon. The burn out Or D-14,834 the oil droplets from the interior of the pellets increase the porosity of the pellets in much the same manner as does the burning of the organic binder or polymer from the interior of the pellets.
This increase in porosity is believed to improve the release of water vapor from the pellets and decrease the occurrence of thermal shock upon firing of the pellets.
An additional benefit realized by the use of a water-in-oil emulsion system, or other system as hereinafter supplementally described, to deliver a polymer binder to mineral ore concentrate in pelletizing operations is a decrease in the amount of contact time required for sufficient commingling of hte polymer binder with the mineral ore concentrate. The contact time of a polymer after the system is sprayed onto the mineral ore concentrate need only be sufficient to allow activation of the polymer on the surface of the mineral ore concentrate. The amount can vary depending upon the system used and the concentration of the polymer binder within the system as well as the total amount of polymer binder sprayed upon the ~ mineral ore concentrate. In desirable embodiments of this invention, sufficient time for commingling of the polymer binder system into the mineral ore concentrate occur by spraying the water-in-oil emulsion onto the mineral ore concentrate upstream of where the concentrate enters the balling apparatus.

~... .~.

D-14,834 Application of a water-in-oil emulsion, or other system as hereinafter supplementallly described, at the mineral ore comcentrate treatment site can be accomplished by applying the system to the mineral ore concentrate through any conventional spraying or dripping apparatus. The inorganic salts are sprinkled from a vibrating hopper or other dispersing means onto the mineral ore concentrate and the composition is conveyed towards the balling apparatus. Alternatively, salt can be delivered from aqueous solutions of about 5 to about 40 percent solid material depending on the solubility of the inorganic salt and the temperature. The activation of the polymers onto the surface of the mineral ore concentrate is rapid, and because the polymers are evenly spread or commingled throughout the mineral ore concentrate, the time required for sufficient commingling to initiate pellet formation is about one minute or less.
This invention also includes the application of binding polymer systems to mineral ore concentrate that are dry powders. In these embodiments the dry powdered polymers are mixed together optionally with the dry inorganic salt.
The resulting powder composition is sprinkled into the mineral ore concentrate as the concentrate is conveyed towards the balling apparatus. The vibration of the conveyor means and the action of the 01332~14 38 D-14,834 balllng drum commlngles the powders lnto the mlneral ore concentrate. Upon surrlclent contact tlme wlth the molsture ln the mlneral ore concentrate, the polymers are adsorbed onto the surrace Or the concentrate.
Sultable contact tlme can be es~entlally lnstantaneous, but orten 18 between about l mlnute to 3 hours or more.
Further commlngllng occurs ln the mlxlng wlthin the balllng drum. The use Or the dry powder polymer embodlments Or thls lnventlon ellmlnates the need ror emulslon spraylng equlpment. Thls lnventlon also lncludes the appllcatlon Or powdered blnders to a mineral ore concentrate ln conJunctlon wlth an appllcatlon Or lnorganlc salt a~ an aqueou~ solutlon.
The useful range Or the concentratlon Or the polymer on an actlve ba~l~ 18 between about 0.001 percent to about 0.3 percent based on welght o~ bone dry concentrate. The prererred range 18 between about 0.001 percent and about 0.1 percent. These range~ are appllcable for both dry and emulslrled appllcatlons Or polymer blnders. The userul range Or the concentratlon Or the lnorganlc salt based upon the welght Or bone dry concentrate 18 between about 0.001 percent and about 0.5 percent wlth the pre~erred range belng between about 0.005 percent and about 0.3 percent.
The lnventlon 18 rurther understood from the . . , D-14,834 Examples below, but ls not to be llmited to the Examples. The numbered Examples represent the present lnventlon. The lettered Examples do not represent this invention and are for comparlson purposes. Temperatures glven are ln C unless otherwlse stated. The following deslgnatlons used in the Examples and elsewhere hereln have the following meanlngs:

ABBREVIATION DEFINITION
AM acrylamlde Apx. approxlmate CaC03 calclum carbonate cc - cubic centimeter CMC carboxymethylcellulose C2 carbon dioxlde dl/g deciliter per gram F degrees fahrenhelt gm/cc grams per cubic centlmeter gms grams HEC hydroxyethylcellulose IV lntrinsic viscoslty lb pound or pounds mm milllmeters NaA sodlum acrylate NaAMPS sodlum salt of 2-acrylamldo D-14,834 -2-methylpropanesulfonic acid NaCl sodium chloride (NaP03)n sodium metaphosphate where n is 2 or more Na2C3 sodium carbonate Na20 sodium oxlde PAM poly(acrylamide) psi pounds per square inch pressure RPM revolutions per mlnute RV reduced viscosity tonne metric ton U.S. United States VA vinyl acetate wt weight wt % weight percent percent by weight unless otherwise specified .

01332~14 D-14,834 LABORATORY EXPERIMENTAL PROCEDURE
In these Examples taconite pelletlzlng conslsts of a two step procedure. Inltlally, seed balls are prepared from the taconite ore uslng bentonlte clay as a blnder.
These seed balls are passed through screens to obtaln seed balls of a slze that pass through a 4 U.S. mesh screen havlng a 0.187 lnch openlng, but not through a 6 U.S. mesh screen having a 0.132 lnch openlng. The seed balls are then used wlth additlonal concentrate and the blnder of lnterest to prepare the larger green pellets.
Flnlshed green pellets are sleved to be ln a slze range between 13.2mm to 12.5mm. Thls can be accompllshed by uslng USA Sleve Serles ASTM-E-11-70. Following slevlng, the green pellets are tested for wet crushlng strength and wet dropplng strength. Addltlonal green lS pellets are drled (not flred) and tested for both dry crushlng and dry dropping strength. For the examples clted, all testlng was done wlth elther wet or dry green pellets.
Seed ball formatlon ln these examples ls begun wlth a sample of 900 grams (bone dry welght) of taconlte concentrate eontalnlng between 8 to 10% moisture. The concentrate is sleved through a 9, 10, or 12 mesh screen and spread evenly over an oll cloth. Next 7.0 grams of bentonlte clay ls spread evenly over the top of 0133251 l D-14,834 the concentrate and mlxed untll homogenous. The mlxture ls lncrementally added to a revolvlng rubber drum havlng approxlmately a 16 inch dlameter and a 6 lnch cross sectlon. The drum 18 rotated at 64 RPM. Humldlty 18 not controlled ln these Examples. Just prlor to addltlon Or concentrate, the lnslde Or the drum 18 wet wlth water from a spray bottle. Whlle rolllng, several handrulls Or the bentonlte-concentrate mlxture ls added to the drum. Dlstllled water ls added when the rormlng agglomerates begln to develop a dull appearance. As seed pellets are formed, they are screened to ~eparate and obtaln pellets whlch pass through a 4 mesh screen, but not through a 6 mesh screen. Captured flnes are readded to the balllng drum and overslzed seeds are reJected. The procedure of readdlng captured rlnes 18 repeated several tlmes untll surflclent seed pellets of the deslred slze have been produced. ~he seed pellets are then rolled for one mlnute to flnlsh the surrace.
Formed seed pellets can be placed ln a sealed contalner contalnlng a damp cloth ~o as to retard dehydrstlon of the pellets.
Green pellet rormatlon ln these ~xamples 18 begun wlth a sample of 1800 grams (bone dry weight) Or mlneral ore contalnlng bet~een 8 to lOS molsture. The concentrate 18 added lnto a 12 lnch dlameter Clnclnnatl 01332Sl D-14,834 Muller and mlxed ror 1.0 minute. Thereafter, an amount Or blnder to be used ln the Example 18 unlformly dlstrlbuted over the surrace Or the concentrate. In Examples uslng emulslon polymers, the emulslrled polymers are unlrormly dellvered dropwlse rrom a syrlnge. When an lnorganlc salt, such as Na2C03, 18 used ln an Example, lt 18 sprlnkled over the sur~ace of the concentrate. For those examples whlch employ a Na2C03 solutlon, a 30 percent salt solutlon ls used.
~or those examples whlch employ powdered polymers, the powder 18 dry blended wlth the lnorganlc sait and the resultlng mlxture 18 then unlrormly sprlnkled over the concentrate ln the muller. The muller 18 then turned on ror three mlnute~ to mlx the blnder wlth the concentrate. The unlrorm mlxture 18 then screened through an 8 mesh screen.
After molstenlng the lnslde Or the rotatlng balllng drum Or tlre, about 40 grams Or seed pellets are added to the tlre. Then the concentrate and blnder mlxture ls lncrementally red lnto the tlre over a perlod Or six mlnutes wlth lntermlttent use Or dlstllled water spray.
Durlng the lnltlal portlon Or thls proccss, small ~mounts Or the concentrate and blnder mlxture are added each tlme the surrace Or the pellets appear shlny.
Typlcally, the latter portlon Or the slx ~lnute rotatlng 01332~14 D-14 834 perlod requlres an lncreased amount of the concentrate and blnder mlxture when compared to the lnltlal part of the rotatlng perlod. Water spray ls applied each time the surface of the pellets takes on a dull appearance.
After the slx minute rotatlng perlod ls complete, the balllng drum 1B rotated one additional mlnute to "flnlsh off" the pellet surface. No water spray ls used during the final one mlnute perlod. Followlng completlon of thls procedure, the green pellets are screened for testlng purposes to a size between 13.2mm and 12.5 mm.
Compresslon testlng ln these Examples ls performed by uslng a Chatlllon Sprlng Tester of a 25 pound range ~tModel LTCM - Serlal No. 567). Twenty green pellets are crushed in the tester wlthin 30 minutes of pellet completlon at a loadlng rate of 0.1 lnches per second.
The pounds of force requlred to crush each pellet 1B
averaged for the twenty pellets and is herein called-the wet crush strength. An additlonal twenty pellets are dried for one hour at 350F. Whlle these pellets are stlll warm to the touch, the crushing procedure ls repeated to obtaln the dry crush strength average measured ln pounds per square lnch (psl).
Drop testlng ln these Examples ls performed with twenty green pellets whlch are tested wlthln 30 minutes 01 332514 D-14,834 of their formatlon. These pellets are dropped one at a time from a helght of 18 inches onto a steel plate. The number of drops to obtain pellet failure is recorded.
Pellet failure ls determined when a crack ln a pellet of approximately a 0.7 mm or greater occurs. The average for twenty wet pellet drops is reported. Twenty addltional green pellets are drled by the procedure set out for the compresslon test and then each ls dropped from a 3 lnch helght. The average number of drops to 1~ obtaln pellet fallure for twenty pellets is determlned and recorded.
Definltlon of acceptable or target pellet mechanlcal propertles is defined in these Examples, within limits of experimental error, by a comparison to the performance of Peridur, a commercial blnder. Perldur was analyzed to be 68 percent carboxymethylcellulose wlth about 16 percent NaCl and about 16 percent Na2C03.
Peridur ls known to produce acceptable results in some plant scale pelletizlng operatlons at a dose of 1.55 lb product/tonne of concentrate. Slnce the product ls about 68% sodlum carboxymethylcellulose, Peridur ls used at an actlve polymer dose of about 1.05 lb/tonne. Perldur is sold by Dreeland Colloids, 1670 Broadway, Denver, Colorado.
Wet drop numbers above about 2.5 and wet crush . ~1332514 D-14,834 numbers above about 3.0 are useful. Dry drop numbers greater than about 2.0 and dry crush numbers above about 4 are acceptable. Comparisons of pellet mechanlcal -propertles for dlfferent blnders need to be made at approxlmately equal pellet molsture contents. Wet pellet propertles are lmportant because wet pellets are transported by conveyors and are dropped from one conveyor to another durlng thelr movemènt. Dry propertles are lmportant because ln klln operatlons pellets can be stacked 6 to 7 lnches hlgh or more. The pellets at the bottom of such a plle must be strong - enough so as not to be crushed by the welght of the pellets on top of them. Dry pellets are also conveyed - and must reslst breakage upon dropplng.
Unless otherwlse stated ln the followlng examples, the term, water-ln-oll emulslon, refers to a water-ln-oll emulslon contalnlng an lnvertlng surfactant. In these emulslons the oll phase ls Isopar M.

D-14,834 EXAMPLE A
The experlmental procedure descrlbed above was used to prepare and test two samples Or green pellets of taconate.concentrate formed wlth a commerclal CMC/NaCl/Na2C03 blnding agent system. The amount of bindlng agent used and the results are presented ln Table III.
TABLE III
Ib Perldur lb actlve per polymer/ wet wet dry wet %
tonne tonne crush drop crush drop H20 1.18 0.80+ 4.6 2.7 4.2 2.1 ---4.6 2.5 4.8 2.1 9.2 + carboxymethylcellulose EXAMPLE I

The expérlmental procedure descrlbed above was used to prepare and test two samples of green pellets of taconlte concentrate formed wlth a PAM/NaA/VA blndlng agent ln a water-ln-oll emulslon. The mole percent of PAM/NaA/VA ls 47.5/47.6/4.9. The oll used ln the external phase was Isopar M. The lntrlnslc vlscoslty of the polymer was 23 dl/g. The amount of bindlng agent used and the results are presented in Table IV.

0133251~
D-14,834 TABLE IV
.
lb actlve lb emulslon polymer/ wet wet dry dry S
per tonne tonne cruqh drop crush drop H20 1.36~ 0.40 4.0 4.5 4.9 2.7 9.1 0.91 0.27 3.5 3.0 3.6 2.4 9.1 also contalns 0.78 lb Na2C03/tonne Thl~ example show-q that the dual addltlon Or an emulslon contalnlng the polymer derlved rrom acrylamlde, ~odlum acrylate, and vlnyl acetate ln a 47.5/47.6/4.9 mole ratlo along wlth Na2C03 produce a taconlte blnder S whlch ls superlor to the blnder system used ln Example A
whlch employs a CMC/NaCl/Na2C03 blndlng agent. At one halr the actlve polymer dose the PAM/NaA/VA-Na2C03 system gave a hl~her wet drop number than the control blnder Or Example A.

EXAMPLE B
The experimental procedures descrlbed ln Examples A
and I were used to prepare and test the green pellets of taconlte concentrate ln this Example. The pellets Or this Example are rormed with either a commerlcal CMC/NaCl/Na2C03 or HEC/Na2C03 binder system. The concentratlon and te6t results are ln Table V below.

~1332514 .

D-14,834 TABLE V
lb actlve polymer/ wet wet dry dry S
binder tonne crush drop crush drop H20 HEC/Na2C03+ 0.78 3 3 4.0 2.5 ---CMC/NaCl/
Na2C03~+ 1.05 4.0 2.9 5.4 2.8 8.0 + 50/50 mlxture.
~+ 68/16/16 wt% (average Or 3 runs) EXAMPLE II

The experlmental procedures descrlbed in Examples A and I were used to prepare and test green pellets Or taconite concentrate formed with a PAM/NaA/VA blndlng agent in a water-ln-oll emulslon. The mole percent Or PAM/NaA/VA ls 47.5/47.6/4.9. The oil used ln the external phase was Isopar M. The concentration and test results are ln Table VI below.

01332514 D-14,834 5o TABLE VI

lb actlve polymer/ wet wet dry dry S
tonne cr~sh drop crush drop H20 PAM/NaA/VA-Na2CO3~ 0.78 3.3 6.2 6.8 4.3 9.8 Thls ls a 50/50 mlxture; PAM/NaA/VA had an IV of 10.3 dl/g.

Thls Example show~ that the dual addltlon of a 47.5/47.6/4.9 mole ratlo o~ PAM/NaA/VA bindlng sy~tem wlth a lower molecular welght as evldenced by an IV o~ 10.3 ln a water-ln-oll emulslon along wlth Na2C03 produces a taconlte blnder system whlch 18 superlor to the current art employlng comblnatlons Or hydroxyethylcelluloQe/Na2CO3 or carboxymethylcellulose/NaCl/Na2CO3. Note that wet drop number, dry crush and dry drop were all better wlth the PAM/NaA/VA-Na2CO3 blnder system.

The procedure~ ror preparlng and testlng the green pellets ln these Examples were the same as descrlbed ~or Examples A and I. These Examples compare pellet strength resultlng rrom ~arylng concentratlons Or polymer blnder 15systems. The concentratlons and te~t results are ln Table VII below. ~

D-14, 834 o ol .. . . .
Op c~J o a~ 0 0 ~1 P~ o , ~ o ~ , U~ , o . . .
3 C~

_ D 3 ~ U ~ 3 O~
C~ U~ ~ 3 ~ ~I
O~
nl O 'D ~ t~ D O l~ 3 ~t. . .. . . . . ~
~-r~ U~
~n . . . S
t~') 3 ~ t~ 3 tr~
o C
~ ~
Hr~l O

a~ O ~U ~ 0 ~~ _1 0 ~ O ~ ~ ~ ~D Z ~
Ct~t~ O O .- O
.s ~c ~a o _, o o o o P ~3 E~

0 ~
o ~ ~
c ~ ~
- l o ~ 0 0 ~ ~ O O E O
U~ I o o " C~
OC . . ~ 0 _~ ~ ~ o ~

:~ ~ P P ~ 0 ~ ~ C
0 ~ 0 ~ ~ ~ ~ ~ 0 ~n ~ ~ a ~
C~ 2 ~ 8 ~ z D C
~ ~ N S: N ~ ~ ~1 ": 0 :E: 0~C 0 ~ 1~~e 0 ~ 0 P~ Z t:~ ZP~ Z C~ Z ~ Z ~ Z ~ ' K ~ H H

~ 01332S14 ~ D-14,834 These examples show that mechanical properties~of taconite pellets formed wlth a PAM/NaA/VA binding agent in a water-ln-oll emulslon lmprove w1th increaslng dose.
Comparlson of the poly(acrylamlde) based polymer blnder system ln Exàmple III ls made at each concentration to a CMC/NaCl/Na2C03 blnder system ln Example C.

EXAMPLE IV
The procedures for preparlng and testing the green pellets in this Example were the same as described for Example I. This Example compares the effect of lntrinslc vlscoslty on pellet s.trength for.a poly(acrylamlde) based polymer blnder system. The lntrinslc vlscosltles and test results are ln Table VIII
below.

01332~14 D-14,834 TABLE VIII

DOSE: O. 78 LB ACTIVE POLYMER/TONNE
wet wet dry dry IV crush drop crush drop H20 10.8 2.8 8.1 5.4 4.3 10.3 23.0 3.2 11.6 5.6 4.1 10.1 ~ Mole percent of PAM/NaV/VA 47.5/47.6/4.9 and also contalns 0.78 pounds Na2C03 per tonne.

Thls example shows that polymer blnder systems of hlgher lntrlnslc vlscosity produce better mechanlcal pellet propertles wlth taconlte concentrate when the polymer blnder 18 a PAM/NaA/VA terpolymer.

EXAMPLE V
The procedures ror preparlng and testlng the green pellets ln thls Example were the same as descrlbed ~or Example I. Thls Example compares the er~ect on pellet stren6th occurrlng when the mole ratlos Or a polymer's monomers are varled. The mole ratlo~ and the test results are presented ln Table IX below.

D-14, 834 0133251~

.
.
~ I a~ u~ ~ c~
Z ~ N

' U~ O t- ~1 . :~0~ . ' ~ ~ ~ ~U ~ ~ C~l.

x ~ . e oq ~ o ~ ~ ~ ~ ~ 0 ~, a:l ~ L C~ O
~ ~ ~ ~ ~ 3 3 ~ p, E-~ h ~ a~
e :~ .
~, o ~ C~
a~ 0 o O O ~ O o ~
a~ ~ . . . . ~ ~1 C~ ~ ~ ~ ~ ~ ~ o o a~
~, C~
J~ ~ O
C~ C) -. 6q ~ al ~ o O J~ :5 U~
a~ L
3 ~) ~ o O ~
bO 00 bO ~1 ~ ~ 3 fi o a)~: ~ o o u~ _~
c~~ ~D X
J~ ~~ . ~~n 3 ~7 o ~ O
C~ ~ ~ ~ ~ ~ ~ ~: C~
d J ~ ~ ~ R
~ O Z ~ 3 u~ Z ~ ~ ~
:,. ~ a ~Ir~ C~J ~ ~ 3 H 1-~ L ~¢
~e~ ~ . ~ ~ ~: ~
o o o ¢ t_ ~ O ct a~ ....
fi~ 3 ~ a~ ~ L~ ~ J ~)3 l~
0133251~
D-14,834 ~5 .

Tblo Example ~how~ that NaA bet~een about 15 and about 41.1 ~ole percent wao not crltlcal to acnle~e ratl~r~ctory perrormance ln an acrylamide polymer.

EXAMPLES D ~ND VI
T~e procedure~ ror preparlng and tcstlng the green pelleto ln t~lo Example ~ere the ~ame a8 descrlbed ror Exampleo A and I. The concentr~t~ons and test re~ult~
are ln Table X below.

iJ
, ?

D-14,834 TABLE X
DOSE- 0.39 LB ACTIVE PAM COPOLYMER/TONNE
PLUS 0.78 L~ Na2C03/TONNE
Copolymer mole S wet wet dry dry S
Example PAM/NaA crush drop crush drop H20 VII 59/411 3.4 5.5 4.4 2.5 9.1 VII 76/242 3.3 4.2 4.6 2.8 8.5 VII 85/153 3.7 4.9 4.8 2.3 8.1 VII 100/04 3.4 2.5 4.4 3.3 8.0 powder D CMC
Perldur5 4.2 2.6 4.4 2.1 8.2 Control t tl.O5 lb emulsion/tonne).
1. IV ~ approximately 20 dl/g.
2. IV - 17.3 dl/g.
3. IV ~ 16.2 dl/g.
4. IV ~ 15.4 dl/g, thls powder is AD-10 sold by Rhone Poulenc 5. 1.17 lb/tonne (containlng 0.8 lb CMC polymer/tonne).

These Example~ show that acrylamlde copolymers contalning O to at least 41 percent Na acrylate are er~ectlve as blndlng agents ror taconlte concentrate.

~.:

0133251~
D-14,834 EXAMPLE VII
The procedures ror preparlng and testlng the green pellets ln thls Example were the same as descrlbed in Example I. The concentratlons and test results are ln Table XI below.

TABLE XI
Dose: As shown ~ 0.78 lb Na2C03~tonne actlve copolymer polymer mole S dose wet wet dry dry S
PAM/NaA lb/tonne crush drop crush drop H20 89/11 0.78 3.9 4.4 6.8 3.1 9.2 77/23 0.78 3.7 6.9 7.9 3.3 9.1 These Examples show that solld poly(acrylamlde) based copolymers ln powder ~orm are e~rectlve blndlng agents ror taconlte concentrate.

EXAMPLES E AND VIII
The procedures ror preparlng and testlng the green pellets ln these Examples were the same as descrlbed ln Examples A and I. The polymer blnder system used and the te~t results are ln Table XII below.

.

0l332~l~
D-14,834 TABLE XII
Dose of PAM based polymers 0.39 lb active/tonne + 0.78 lb Na2CO3/tonne wet wet dry dry %
Composition crush drop crush drop H20 PAM/N Decyl Acrylamlde 2.7 3.0 4.7- 3.0 8.5 (99/1) nonionlc PAM/Slpomer Q5-801 3.1 2.4 4.4 2.8 8.4 94/6 cationlc CMC/NaCl/
Na2CO 2 (cont~ol) 4.2 2.6 4.4 2.1 8.2 1 Sipomer Q5-80 is Dimethylaminoethylmethacrylate/Dimethyl sulfate quaternary salt.
2 0.8 lb CMC/tonne.

These Examples show that emulslons of nonlonlc poly(acrylamide) based polymers wlth long chaln hydrophoblc groups and cationic modl~led PAM perform well as taconlte binders when compared to CMC based products. The results obtalned from these Examples demonstrate that an emulsion of PAM/NaA/VA is better than or roughly equivalent to a CMC/NaCl/Na2C03 bindlng agent ln both drop tests and compression tests.

0133251~
D-14,834 EXAMPLE IX
The procedures for preparing and testing the green pellets ln thls Example were the same as described ln Example I with the exceptlon that the lnorganic salt used in thls example ls applied as a 30 percent aqueous solutlon. The polymer blnders ln thls example are ln a water-ln-oll emulslon. These tests were conduc~ted on taconlte ore concentrate and demonstrate the effect of applylng the polymer binder emulslon and lnorganic salt solutlon ln different sequences to the mlneral ore concentrate. When these llqulds are applled to the mlneral ore concentrate separately, the flrst liquid ls mixed wlth the mlneral ore concentrate ln a muller. The second llquld ls then added and the total composltlon ls - mlxed for an addltlonal 3 mlnutes. The test results are presented ln Table XIII below.

. 01332514 D-14,834 TABLE XIII
Dose: emulslon 1.1 lb emulsionl/tonne ~ Na2C03 0.81 lb/tonne Total Method of Mlnutes Wet Wet Dry Dry S
Additlon Or Mlxln~ Drop Crush Drop Crush Water Emul~ion2 6 then Na2C03 Solutlon 3 6.7 3.8 2.3 5.2 8.9 Na2C03 Solutlon 6 then Emul~lon 3 8.4 3.7 2.0 4.0 9.1 Emulsion and Na C0 Solutlon Appll~d Together3 6 5.2 3.7 2.2 4.8 8.

1 The emulslon contaln~ 27.6 percent actlve polymer.
2 The emulslon was PAM/NaV/VA ln a mole percent Or 47.5/47.6/4.9.
3 The emulslon and lnorganlc salt solutlon were applled concurrently to the taconlte ore concentrate rrom sepsrate contalners.

D-14,834 Thls example demonstrates that an lnorganlc salt solutlon can be applled ln con~unctlon wlth polymer blnders to effectively agglomerate a mineral ore concentrate.

EXAMPLE X
This Example was conducted on taconite concentrate ln the same manner as Example I. Thls example compares the effectlveness of a blndlng agent ln a water-ln-oll emulslon both with and wlthout an lnvertlng surfactant.
Thls test lnvolved a two-step addition. The Na2C03 powder was added to the taconite concentrate and mixed for three minutes. The emulsion was then added and the entire composition was mixed an addltional three mlnutes. The test results are presented ln Table XIV.

01~32S14 D-14,834 TABLE XIV

Wet Wet Dry Dry S
Drop Crush Drop Crush -Water Emulslon with lnvertlng surractant 5.1 3.9 2.0 4.4 8.5 E ~ ~
surfactsnt 3.7 3.9 2.0 3.6 8.3 ~ Both emulslons contaln PAM/NaA/VA in a 47.5/47.6/4.9 mole ratlo at l.l pounds Or emulslon per tonne and 0.81 pounds Na2C03 per tonne.

,~

~133251~
D-14,834 This experlment demonstrates that acceptable green pellets are formed both with and without an lnvertlng surfactant in the emulsion.

.

0133251~

64 D-14,834 EXAMPLES F AND XI
The rollowln~ Examples were conducted ln rull scale plant wlth a full slze balllng drum and klln. In these Examples 55 tonnes per hour Or taconlte concentrate were conveyed to and processed ln the balllng drum. The selected blndlng agent systems were added by spraylng onto the taconlte ore concentrate Ju~t prlor to enterlng the balllng drum and by vlbratlng the Na2C03 powder onto the taconite ore concentrate. The average contact tlme Or the blnders wlth the mlneral ore concentrate berore enterlng the balllng drum was approxlmately 0.5 to l mlnute. The average slze Or the green pellet~ obtalned were between approxlmately one-rourth to one-halr lnch ln dlameter.
In Example XI an anlonlc water-ln-oll emulslon Or PAM/NaA/VA ln a mole percent Or 47.5/47.6/4.9 was used as a polymer blndlng agent. The quantltles Or blndlng agents used and the results obtalned by the poly(acrylamlde) based polymer blnding agents are detalled ln Table XV. Comparatlve results ~or other blndlng agents are ln Table XVI.

D-14,834 TABLE XV

PAM/NaA/VANa2C03 Wet Wet Dry2 Te~tlgal/ lb/ lb/ lb/ Compresslon 18" Compresslon E~ample Number mln tonne mln tonne psl drop psl IX 1 0.145 1.4~ 0.73 0.80 --- --- ---IX 2 0 0 0.73 0.80 --- --- ---IX 3 0.145 1.45 0.00 0.00 --- --- ---IX 4 0.10 0.94 0.73 0.80 1.5 8.4 2.3 IX 5 0.11 1.05 0.37 0.40 1.6 7.0 1.8 IX 6 0.14 1.34 0.95 1.04 2.1 10.6 2.8 IX 7 0.12 1.12 1.70 1.85 2.1 9.6 3.1 0 16363 2 5 1 4 D-14,834 TABLE XV CONTINUED
Test Avg. Fired3 S Or Flne~ 18" Drop Number Compres~lon That Break S S Mln. after ~tart of blnder addltlon Cont. p~l Under 200 psl FeO H20 10 20 30 1 320 19 0.43 9.6 __ 16.0 7.3 7.6+
2 -- -- -- 9.2 6.0 4.2 3.6 --3 -- -- -- 10.1 4.5 11.1 9.3 --4 194 63 0.35 10.1 8.7 7.8 8.5 --244 50 0.31 9.4 8.o 9.3 8.0 --6 118 85 5.1 -- 10.5 18.7 13.2 6.6+

7 259 42 0.31 9.8 12.5 12.1 11.9 --~, ~ 3 67 D-14,834 TABLE XV CONTINUED
Slze Dlstrlbutlon Or Pellets Test Number Cont. +1/2" ~7/16" +3/8" +11/32" +1/4" -1/4"
1 2.2 43.2 43.7 7.8 1.4 1.8 2 13.6 57.1 19.9 4.8 2.1 2.5 3 2.9 33.5 40.8 14.3 4.8 3.7 4.7 31.8 46.4 8.5 2.8 5.9 4 2.7 27.9 44.6 15.1 4.6 5.1 1.4 45.4 44.3 6.8 1.1 1.0 6 1.2 14.1 58.6 20.2 3.8 2.1 7 1.9 22.5 57.9 12.9 2.8 1.9 1 Samples were obtalned by (1) rllllng a basket with green pellets, (2) transportlng the basket through the klln operatlon, and (3) testlng pellets from the top, mld-top, mld-bottom, and bottom Or the basket.
2 Pellets contaln no molsture, samples are taken Just prlor to klln operatlons.
3 Samples are taken after drylng ln klln.
+ 48 MIN
++ 40 MIN

~!133251~1 D-14,834 ~1 .,1 ~ o~
W ~I
S ~ O . I ~D
I V

.,~

U~
U~
~ ~ I _l o DJ ~ I u~ ~
~ I ~U ~

r Do .
K K O
~ a ~ _, ~ ~: ~ o . o o ~0 _ _ K K
., ~ ~0, ~, ~-~
# ~
_ ~ _ ~ 0 _I
~0 ~ C~ ~0 C _~ 0--0 ~ 0 0 ~ O C 0 0 K
Z O ~ Z O ~ -~ O--g ~ C~ ~C~ C~ ~ ~
~0 P C~ ~0 ~
.,~ ~ ~: 0 e~ 0 ~; ~ C:~ Z--~ z_~ ~ _ ~ #
'~

~, ~
. i~, D-14,834 These Examples show that the 18 inch drop number for wet green pellet~ and the dry compresslon strength Or dry pellets lmprove wlth lncreases ln Na2C03 concentratlon. Varylng the concentratlon Or Na2C03 dld not show a trend ln the compresslon strength Or rlred pellets.

01332514 D-14,834 SUPPLEMENTARY DISCLOSURE
The polymers of this invention may be applied to the mineral ore concentrate as a dispersion in a non-aqueous dispersion medium, that is for example in one or more of the following forms: (i) a water-in-oil emulsion in which oil is the non-aqueous portion of the emulsion, or (ii) a dispersion of fine polymer particles in oil such as may be made by removing water from a water-in-oil emulsion or by methods described in U.S, Patent No.
4,325,861 of Braun and Rosen. "Oil" is used broadly in this context to include any vehicle, preferably an organic vehicle, which is a non-solvent for the polymer. The size of the fine polymer particles is preferably such that, in the selected dispersion medium, they either resist settling and stratification, or they have a tendency to settle or stratify but are easily redispersed before addition to the mineral ore concentrate. The size of the dispersed fine polymer particles required for such stability will therefore depend on the characteristics of the selected dispersion medium, particularly its density and viscosity.

01332~1~ D-14,834 Additional inorganic salts which may be used in this invention include dolomite and magnesium carbonate.
Desirable polymers for use in this invention include those of the previously described formulas wherein R2 includes equivalent cations such as NH4.
The third class of polymers used in this invention includes those polymers in the form of dispersions in oil. A representative but non-limiting list of polymers useful in this form includes those set forth previously in Table I.
The polymer dispersed in oil systems used in this invention may be a dispersion of fine particles of polymer in oil such as may be made by removing water from water-in-oil emulsions of the kind described previously. Dispersions of polymers in oil used in this invention may also be dispersions of fine particles of polymers prepared as described for example in U.S. Patent No.
4,325,861 of Braun and Rosen. Desirable hydrophobic liquids used in these dispersions are the same as the hydrophobic liquids used in water-in-oil emulsions referred to previously.
B

72 D-14,834 While the process of this invention comprises using polymer dispersions or dry powders alone, it also-comprises their use with other materials such as bentonite. In a preferred method of practicing the present invention, the water-in-oil emulsion contains approximately 30 weight percent of a copolymer (prepared from approximately 50 weight percent acrylamide monomer and 50 weight percent sodium acrylate monomer), 35 weight percent water, 35 weight percent Isopar~ M, and a nonyl phenol ethoxylate as a surfactant.
Before spraying onto taconite concentrate, the emulsion may be filtered to remove gels which might clog the spray nozzle. The emulsion is added at the rate of about 0.6 pounds per tonne. In accordance with the invention of Canadian Patent Application Serial No. 509,056-3 filed May 13, 1986, and assigned to a common assignee, bentonite may also be added at the rate of 9 pounds per tonne.
Preferably, the bentonite is added after the emulsion and just before the taconite concentrate enters the pelletizing drums or discs.
The process of this invention may also be used to make flux pellets. These pellets are made I r`' ~

01332514 D-14,834 by adding to the taconite concentrate an inorganic material that tends to reduce the acidity of the resulting pellets. The inorganic material may be one or more of the following dolomite (Ca,Mg)CO3), high calcium dolomite (also known as limestone or calcium carbonate) and magnesium carbonate. These may be added prior to, simultaneously with, or after the addition of the polymer to the particulate material. Flux pellets are sometimes described in terms of their basicity -- the ratio of bases to acids defined as the ratio of weight % (CaO + MgO/
(SiO2 + A12O3). When basicity is measured, flux pellets may typically have a basicity ratio of about 1.0 to 1.1.

In addition to the designation used in the Examples listed previously, the additional abbreviation (Ca,Mg)CO3 means dolomite.

EXAMPLE XII
Following the procedures used for preparing and testing green pellets described above in Example I, dispersions of fine particles of a polyacrylamide polymer in an oil dispersion medium were added to taconite concentrate from the Mesabi range at the rate of 0.36 pounds of dispersion product per tonne , .

D-14,834 (for an effective rate of 0.18 pounds of polymer per tonne). These dispersions contained 50 weight percent light mineral oil, fifty weight percent polymer and essentially no water. In all cases, bentonite was also added at the rate of 9 pounds per tonne. The results obtained are set forth on Table 17.
These dispersions varied in the polyelectrolyte charge density that they exhibited, as shown under the column headed "charge" in Table 17. The non-ionic polymer used in Test 1 was obtained as a homopolymer of acrylamide which applicants believe had an I.V. of about 15. The anionic polymers of Tests 2 and 3 were obtained as copolymers of acrylamide and sodium acrylate; I.V., about 15. The polymers of Tests 4 and 5 were prepared from acrylamide and quaternary salts of dimethyl-aminomethyl methacrylate; I.V., about 7 to 15.

As a control, a water-in-oil emulsion which contained 30 weight percent of a copolymer prepared from acrylamide monomers and sodium acrylate monomers (approximately 50/50 weight percent) was added at the rate of 0.6 pounds per tonne (for an effective rate ,~

of 0.18 pounds of polymer per tonne) with bentonite added at the rate of 9 pounds per tonne. The results are also set forth on Table 17.

% H20 Ionic Green Green Dry in Test Character Charqe Drop Crush Crush Pellets 1 Non-ionic None 5.2 4.711.4 9.4 2 Anionic Med. 10.1 4.4lO.9 9.6 3 Anionic High 6.5 4.1 9.9 9.4 4 Cationic Med. 5.6 4.713.3 9.4 Cationic V. High5.4 4.911.5 9.5 Control Anionic Med. 7.0 4.7 9.6 9.7 The procedures for preparing and testing pellets used in the following Examples XIII to XVI

were the same as described for Example I. The weights per tonne in these examples are based on the weight of taconite concentrate after removal of all moisture.

EXAMPLE XIII

Relatively high sodium carbonate systems, e.g. those having approximately 2.5 to 3 lb/tonne of added Na2CO3, may be used with the polymer systems of this invention to obtain improved green ;

01 332514 D-14,834 drop performance. In this example, polymer is used in the form of a water-in-oil emulsion containing approximately 30 weight percent of a copolymer (prepared from approximately 50 weight percent acrylamide monomer and 50 weight percent sodium acrylate monomer), 35 weight percent water, 35 weight percent Isopar M, and a nonyl phenol ethoxylate as a surfactant. Polymer delivered as a water-in-oil emulsion and Na2CO3 delivered as a powder were added to a taconate concentrate in the amounts and with the results shown in Table 18.

lb.
lb emul- Na2C3 sion per per green green dry % H2O
tonne tonne drop crush crush in pellets 0.8 3.0 5.4 4.0 7.9 8.7 EXAMPLE XIV
In some cases it may be desirable to use reduced levels of Na2CO3 in order to reduce the sodium content of the pellets. Sodium in the pellets is believed to lead to the creation of sodium cyanides in the furnace which, insufficiently large amounts, lead in turn to corrosion of the furnace ~;, 01332514 D-14,834 walls. Therefore, some furnace operators prefer to operate at least then about 0.075% by weight of sodium, which may be expressed as Na2O 0.075%
sodium corresponds to about 3 lb/tonne of Na2CO3 if there is no other significant source of sodium added or in the taconite concentrate. Most preferably one may operate at sodium levels of about 0.03% or less of sodium expressed as Na2O (i.e., less than about 1.2 lb/tonne of added Na2CO3. In order to reduce sodium we have used dolomite [(Ca,Mg)CO3 or CaCO3] in place of Na2CO3 with the polymer of Example XIII and obtained the results shown in Table 19. This table shows that dolomite is not as effective as an equal weight of Na2CO3 but that a slightly higher dose used with a somewhat higher dose of polymer required to achieve the same green drop. This experiment shows a dosage of polymer and dolomite found to achieve green drop comparable to that achieved w/Na2CO3 in Example XVII.

lb emul- lb dolo- % H2O
sion per mite per green green dry in tonne tonne drop crush crush pellets 0.8 3(1) 4.3 3.6 3.8 9.2 1.0 6(1) 5.3 3.3 3.2 9.4 (1) Delivered from 20% slurry in water.

"~

~1332514 D-14,834 EXAMPLE XV
We have found that by the combination of both Na2CO3 and dolomite at lower levels with dolomite and the polymer of Example XIII, the levels of both green drop and dry crush are unexpectedly increased to improved levels, as shown in Table 20.
The table also illustrates that limestone (CaCO3) an be substituted for the dolomite, if desired. We believe that magnesium carbonate may also be substituted for dolomite and that combination of these inorganic salts will be comparably useful.

lb. lb lb lb emulsion dolomite limestone Na2C03 % H20 per per per per green green dry in tonne tonne tonnetonne drop crush crush pellets 0.8 6.0(1) -- 1.2(2) 6.1 3.9 9.1 8.6 0.6 5.0(1) -- 1.2(2) 5.2 4.5 8.5 8.5 0.8 -- 6.o(3) 1.2(3) 5-0 4.1 8.0 8.6 (1) Delivered from 20% slurry in water (2) Delivered from powder.
(3) Delivered together as Na2C03 dissolved in sufficient water to make a 35% slurry of the limestone.

EXAMPLE XVI
Table 21 shows that pellets with outstanding green properties may be obtained when using the 01332514 D-14,834 polymer dispersion of Example XIII in flux pellets.
Table 41 also illustrates that the omission of Na2C03 affects both the green drop and dry crush of the pellets.

lb/tonne % H20 green green dry in Dolomite Limestone Emulsion Na2C03 drop crush crush pellets 112(1) 112(1) 1.0 3.o(2) 9.0 4.3 9.1 9.2 112(1) 112(1) 1.O l.2(2) S.6 4.2 9.0 9.0 112(1) 112(1) 1.O 3 o(3) 6.6 4.3 7.1 9.2 112(1) 112(1) 1.0 0.0 4.7 3.5 3.4 9.6 (1) Added from a 1/1 blend as a 50% slurry in water to 60%
taconite slurry (in water) prior to filtration and prior to the additional polymer and sodium carbonate.
(2) Added from a water solution downstream of the filtration of the taconite/dolomite/limestone slurry.
(3) Added from a water solution upstream of the filtration of the taconite/dolomite/limestone slurry.
B

Claims (39)

1. A process of producing pellets consisting essentially of:
(a) selecting a water-soluble polymer either in a water-in-oil emulsion or as a dry powder of poly(acrylamide) or poly(ethylene oxide) based polymer;
(b) mixing a binding quantity of said polymer with a taconite concentrate;
(c) pelletizing in a balling drum the mixture of step (b) to form green pellets; and (d) indurating said green pellets with heat.

2. The process of claim 1 in which the polymer is applied as a dry powder.

3. The process of claim 1 in which the polymer is contained in the aqueous portion of a water-in-oil emulsion.

4. The process of claim 1 wherein said polymer is a poly(acrylamide) based polymer.

5. The process of claim 4 wherein said polymer contains repeating units of the following formula:

wherein R2 is an alkali metal ion, f and g are from 5 to about 90 percent, f + g = 100, and d is from about 1,000 to about 500,000.

6. The process of claim 4 wherein said polymers are derived from at least one of the following groups of monomer units: acrylamide, methacrylamide and derivatives thereof of the formula where R13 is a hydrogen atom or a methyl group;
R14 is a hydrogen atom, a methyl group or an ethyl group;
R15 is a hydrogen atom, a methyl group, an ethyl group or -R16-SO3X, wherein R16 is a divalent hydrocarbon group having 1 to 13 carbon atoms and X is a monovalent cation.

7. The process of claim 1 wherein said polymer is applied to said particulate material at an active polymer concentration between about 0.001 to about 0.3 percent by weight.

8. The process of claim 1, wherein an inorganic salt is commingled with said particulate material, said particulate material being mineral ore concentrate.

9. The process of claim 8 wherein said inorganic salt is an alkali metal or alkaline earth metal salt of carbonates, halides, or phosphates, or a mixture thereof, and said mineral ore concentrate is taconite concentrate.

10. A product of the process of claim 1.

11. The process of claim 1 wherein green pellets of mineral ore are obtained by agglomerating said particulate material and said green pellets are then fired by a means for applying heat sufficient to indurate said ore.

12. A product of the process of claim 11.

CLAIMS SUPPORTED BY SUPPLEMENTARY DISCLOSURE

13. A process of agglomerating a particulate material, consisting essentially of commingling said particulate material with a binding amount of a water-soluble polymer wherein said polymer is applied to said particulate material as a dispersion in a non-aqueous dispersion medium.

14. The process of claim 13 in which fine particles of the polymer are dispersed in a dispersion medium which is a non-solvent for the polymer.

15. The process of claim 13 wherein said polymer is a poly(acrylamide) based polymer.

16. The process of claim 15 wherein said polymer contains repeating units of the following formula:

wherein R? is an alkali metal ion, f and g are from 5 to about 90 percent, f + g = 100, and d is from about 1,000 to about 500,000.

17. The process of claim 15 wherein said polymers are derived from at least one of the following groups of monomer units: acrylamide, methacrylamide and derivatives thereof of the formula where R13 is a hydrogen atom or a methyl group;

R14 is a hydrogen atom, a methyl group or an ethyl group;
R15 is a hydrogen atom, a methyl group, an ethyl group or -R16-SO3X, wherein R16 is a divalent hydrocarbon group having 1 to 13 carbon atoms and X is a monovalent cation.

18. The process of claim 13 wherein said polymer is applied to said particulate material at an active polymer concentration between about 0.001 to about 0.3 percent by weight.

19. The process of claim 13, wherein an inorganic salt is commingled with said particulate material, said particulate material being mineral ore concentrate.

20. The process of claim 19 wherein said inorganic salt is an alkali metal or alkaline earth metal salt of carbonates, halides, or phosphates, or a mixture thereof, and said mineral ore concentrate is taconite concentrate.

21. The process of claim 20 wherein said inorganic salt includes less than 3 lb/tonne of added Na2CO3 and at least one member selected from the group consisting of dolomite, magnesium carbonate and calcium carbonate.

22. The process of claim 21 wherein the Na2CO3 is added to a flux slurry before filtration of taconite concentrate.

23. A product of the process of claim 22.

24. A product of the process of claim 13.

25. The process of claim 13 wherein green pellets of mineral ore are obtained by agglomerating said particulate material and said green pellets are then fired by a means for applying heat sufficient to indurate said ore.

26. A process of producing pellets consisting essentially of:
(a) selecting a water-soluble polymer dispersed in a non-aqueous dispersion medium;

(b) mixing a binding quantity of said polymer with a taconite concentrate;
(c) pelletizing in a balling drum the mixture of step (b) to form green pellets; and (d) indurating said green pellets with heat.

27. The process of claim 26 in which fine particles of the polymer are dispersed in a dispersion medium which is a non-solvent for the polymer.

28. The process of claim 23 wherein said polymer is a poly(acrylamide) based polymer.

29. The process of claim 28 wherein said polymer contains repeating units of the following formula:

wherein R? is an alkali metal ion, f and g are from 5 to about 90 percent, f + g = 100, and d is from about 1,000 to about 500,000.

30. The process of claim 28 wherein said polymers are derived from at least one of the following groups of monomer units: acrylamide, methacrylamide and derivatives thereof of the formula where R13 is a hydrogen atom or a methyl group;
R14 is a hydrogen atom, a methyl group or an ethyl group;
R15 is a hydrogen atom, a methyl group, an ethyl group or -R16-SO3X, wherein R16 is a divalent hydrocarbon group having 1 to 13 carbon atoms and X is a monovalent cation.

31. The process of claim 26 wherein said polymer is applied to said particulate material at an active polymer concentration between about 0.001 to about 0.3 percent by weight.

32. The process of claim 26, wherein an inorganic salt is commingled with said particulate material, said particulate material being mineral ore concentrate.

33. The process of claim 32 wherein said inorganic salt is an alkali metal or alkaline earth metal salt of carbonates, halides, or phosphates, or a mixture thereof, and said mineral ore concentrate is taconite concentrate.

34. The process of claim 33 wherein said inorganic salt includes less than 3 lb/tonne of added Na2CO3 and at least one member selected from the group consisting of dolomite, magnesium carbonate and calcium carbonate.

35. The process of claim 34 wherein the Na2CO3 is added to a flux slurry before filtration of taconite concentrate.

36. The process of claim 26 including the additional steps of selecting an inorganic material that tends to reduce the acidity of taconite concentrate in an amount sufficient to result in a flux pellet.

37. The process of claim 36 wherein sodium carbonate is commingled with said inorganic material selected to create the flux pellet.

38. A product of the process of claim 26.

39. The process of claim 26 wherein green pellets of mineral ore are obtained by agglomerating said particulate material and said green pellets are then fired by a means for applying heat sufficient to indurate said ore.