CA2017886A1 - Procedure for dust control in granulated materials - Google Patents

Abstract

ABSTRACT

To control and bind dust in granulated materials a solution of molasses and a concentrated earth-alkaline-chloride solution is sprayed on.

Description

~7~38~

The lnv~ntlon addro~s~ ~ procedur~ ~o: e ~he preventlon of th~
form~tlon of du~t ~u~ng. ~h~ lo~ing ~1 ~ ran~portatlon of granular materlals or p~l:Let~ p~cl~ ~l,y granular fertlllz~r~.
F~rtlllzer~ ar~ m~nufac'c~ur~d~ on ~ ~ve~ t ln~a~lng ~c~le~ ln granular ~or~ and ar~ 'cran~portsd ln 1~ ~o~ bulk l~dq, ~ry-pre~ grar~ula~lon ls th~ mo3t common p~ ,o~e~s u~ed to manuacture thes~ qrartulates. Th~ pro~e~ ~orc~s~ l ;h~ ~ontained ~ to ~orr~
a hard shell around the materl~l ~o bo g~nul~ed. A prefe~red granular slze o~ 1.0 to ~.0 ~ then ol~taln~d through cru~hlng and ~iftlnq~
The ~act that g~anulatlon aldlng mater~ ~ are a~de~ to th~
lngredlent r~ater~als mlxtu~ ~n the pr~ Idl3~tlon o~ ~all kernel qxanulat~s ~8 well kno~n~ ~he DE-~S 2~ , ~1 585 d~s~r~bes the addltion of org~nl~ or lno~qanlc b~ndl~ ~g a~ent~, suctl a~
mola~se~, starch, calclum chlo~id~a a~ ~ell a~ alkaline and aart~ lk~311ne-3ulph~ta ~nd nltrat~, In the compac~lng of ~hom~s-phospha~e ln th~ ~m~un~ of 2 tc 3 per~ent. ~n addl~lorl, ~ertaln t~mperature range~ ~nd treal~ ~ .times durlng. the comp~tlng p~ocess and d~prln~ the follc ~-u~ trea~ments are re~ulated ~
The ~E-PS 36 18 058 d~ rlbes a ~rocedu ~o ~or th~ granulatlon of wa~er soluble fsrtlllzer~ wl~h hlgh Kle ~e~te ~ont~nt~ nlfled Ly the f~ct, th~t ~olubl~ an~fo~ ea~lly colloSd ~olu~le 9ubatancers from the cl~s o~ ~ono~ dl o ~ ~oly-~accharid~ and~or the derlved slngle hydro~hlle a~ da~ . to th~ materla~ to be granulated ln ~olld or ~lutlon for~. !rhie ~rnount~ ad~ed rang~
from 0.1 to 5 perc~nt. ~n ~ddltlon, 5~ ccharo~ n 3011d c:r ~a~
~ugar rlch molas~e~ may lil~ u~od.
The DE-~Y 11 '77 177 de~c~ibo~ the a~dlt lon of rn~gno~ium sul~h~ta and magnes~u~ ~:hlorl~e ~ulutlon~ ~18 gra nul~tlon aldlng ~u~ anc~ the l)~ 08 33'04 303 ~e crlb ~ the utll~atlor~ o~
magno~ chl~rlde ~olut~on a~ a bln~ln g ~gent ln the productlon of pell~s made ~rom cruiihed ~teel ~urn !~ce and ate~l prodl~ctlon s ludge .
~hc ~ran~ es produced ~y t~le common m~nu~acturlng p~oce~se~
especial~y aa a re~ul~ o:~ cru~shln~, havf~ Rharp edg~ and ~orner3 which ar~ gxoun~ of ~ ~u~ing ~he load~ng ~nd tran~por~lnq of th~
granulclt~. Thls resu~s ~n the cre~tio n o~ dU~t, whl~h i~
~nde~lIdbl~ ~u~lrlg the tran~port and en ~ appllcation o~ the gr~r~ulat~s and lead~ to ~na~ept~ble en ~ironmental con~equence~.
~t ~ known, that ~he p~v~ntion of the! al~ove ~entlon~
phe~omenon i~ be~nq ~tt~rnpted th~ough t ~e l~tlng o~E~ of ~xt~emely ~1n~ Xernel~ 1~! g~anulateO I 1 pr~ctlce howe~,relr~ thi~
treatlQent ~B not 8U~ lelnt to remov~ ~ ~r~ace ~u~t ~ r~1cle~ o~
to impro~e the resl~tiln~ to du~t ~orm~ tlon of the edg~3~ {~orners dnd ~ur facc~ o~ ~he g~anula~s~ .
A proc~dure to ln~prov~ th~ ~ur~a~e ~Rarlresl~tance of Kali 88~

fertll~zer ~nulate~ knovn ~om DD P~ 136 956. ~ter the ~ranulatlon proce~, th~ K~ rtlllz rs granulat~3 ~re ~lven a follow-uE) ~re~t~ent ;:onsl~tln~ of du~t ~emoval ln ~n al~
.lgltator~ followed ~y the appllcatlon ~ ~ sur~ace tre~tment ~lth water or water based ~dd'ltlve~ ~nd 'che drylng ~nd coollng of th~
~hus tr~ated granulate~. The b~ fo $he pr~cedur~ ls th~2 ~act th~t the re~Ralnln~ un~tabl~ edga~ or c rner~ ~f the ~nulat~
su~ace can ~e 9trang~hehed through ab oPbtlon or r~cry~tallzation an~ th~t th~ overall sllrfa~ ~trength o~ th~
granulate can be l~p~oved.
The ~E-OS 30 03 BB3 8upp~e~nt~ the fl~ Idlngs of the p3~evlously di~cu3~ed p~'cent appll~atl~n through ~ le ~b~ervatlon that an optlmal ~urface ~trength qain can be ~ ~ined, ~o~dln~ to OS, at a temperature range ~ro~ ~ to lOO ~ legre~ ~elsius, in ~o~binatlon with ~ minl!num treat~ent ~ ~o o~ lO ce~ond~, in an atmosphere wlth high ~Qis'cure ~ont~nt.
The tre~l:ment procedure ~e~crlbed 2Ibov r~aulre~ exten~ve exp~ndlture ln ad~ltlon to tho granul~ lon and si$tlng eguSp~ent and i8 only appllcab1e a~ th~ granul~t ~r~du~or~ locatlonO sln~e the he~t requlr~d by ~he pro~es~ 18 2~ yproduc:t~ o~ granulat~
produc~on. ~h~ pro~edu~e Is not ap~1 c~ble, ~ven ~,rhen disr~gar~ing th~ regulre~l inve~t~ent at d malnten~n~e co~ts, fvr ~ranulated Kall ~ro~uctY~j ~?hlch are ~tc red fo~: prc~longed perlod3 of tlme ln piles at mlddlemen and ar~ t ~en r~load~d. It ls kno~n that prolonged ~torage ~rlo~ and the a~3oclat~ physical e~fects, such ~8 sto~ge pre~ur~ and c hans~6 ln the ~ol~tu~e ~ontent o the a~blent ~s~mo ph~e, ne~ ~ivoly a~f~ct gr~nul~to~
treated ln the abovo ~en~ioned ~rocedur e.
5~he ch~llenge underlyln9 thl~ invontlon V~ to develoEI a ~tcl~ed~re for the pre~n~l~n o~ du~ ~o rm~tion durlng the loa~lng an~ tran~port~tl~n of yr~nul~te~ ~r pel l~s, o~peclally ~ertlllzer granulates, whlch llrould optl m21lly n~e~t 'che requlrem~nts of belng ~nu1ron~en'c~1ly ~ rl~n~ly, allo~ing for long storage ~e~ ~od~ of the trea'ce~ gr~nulat e~, and belng e~y to apply .
Thl~ accompll~had by t:hi 1nvent10n through the addi~10n o:~ a 11~au1d mlxture Iqust ~n~c~ol/b~nd1ng ~1 ~ture~ o~ org~nic or 1r~u~anlc ~l~bstanco~ In ~t~r ~olution to the granulat~s~ ~here t~le ~ubstance aro ~ully ~olubl~ ln on~ ~nothe~ ~nd llh~re the organlc ~ubstancP for~s ~h2. ~u~t bln~ln 3 agent ~nd ~he ~nor~an~c ~u~sta~e control~ th~ mai~tu~e ~ontent o~ the o~ the m1xture .
The ap~licablo du~t csnti~l~b1nd~ng sllIx ture mu~t st1ck t~ the granul~t~ surfa~ dtt~3 ~ust not 41~ol~r~ o~ d11uto through the ab~orbt10n o~ mol tur~ fr.om th~ atmo~ph ~r~. In ~ddit~on~F th~
m~xture ~ust not glv~ up ~ol~tur~ to th ~ po1nt o~ lov~ ng it~
~sticky~ property dur1n~ :the ~Iry1ng ~ro ~e~lur~. In ~eneral sub3tan~es are utlli~çd th~ exh1blt re Latlvely high vl~osity a~
room tem~ atur~ and pO~S~3 wal:er r~pel Io~t pro~ert1es. ~hese vi~cou~ ~ul~tance~ ~h~uld, also ~xhib1t ~ ~gh ~ h polnt, s1n~:e i .

Z~3~3L7~ 3 to achl~vQ optl~un~ co~re~ag~ a ~r~y-on¦ te~erature o ~round ~û
ce l 51 u3 1~ requ l r~d .
The long E3tor~g~ p~rlQd2~ o~ th~ treate~ ~ ~ranulate 1~ due to the lor3gevlty o th~ ~u~t blln~ing ef~ec:t o E ~he lnvorlted du3t con tr ~ ~b l nd i ng ml xtU~e . i Molas~s, whlch ~ ~ the s~cond ~ta~e ~ ~ ~ugar in bcet ~u~ar p;odu~t ion, 1~ e~pec~ sultabl~ to a~la the organlc substance, slnce lt exhlblt~ ~h~ ab'Dv~ me~nt~on~d ~ualltle~. Fo~ th~
lnorqanlc :~ub~tan~s Ca~ nd M~C12 ar~ F ~3pocl~11y ~ultablo;
Ob~ec~ of thls invehtlon 1 a ho~ ~g~n~ouu mlxtu~e o~
molass~ ~lth ~7 pe~cent ~suSIax co~ itont ~nd a solut~on CaC12 w~th conc~ntràtls~n of 30-~0 p~rc~nt CaC12 or a solution o~ MgC12 ~Ith 23-33 perc~ !n~ MyC12, ~hl~h Dptl~nally me~ts th~ chall~nge~ faco~ b,y d d~ !at ~ontrol/~indlng pr oduct .
~he manu~ tur ing of the hQmogeneoua ~ x~uLe can take place at roon~ temperature in ~n a~lt~'co~ o~ulpp el contalne~.
The ~nlxln~ o~ commerclally av~lla~ la~ with a pH ~igurQ o~
a . 2 to 8 . 7 ~ith a CaCl~ ~olutlon, wh~c ~l~o ha~ a p~ f lgur~ of ~pproxl~at~ly ~.0, cau~e~ 3 choalcal re ~ctlon~ vtllch 15 Rignifled throu~h the redu~t~ on of . ttie pJI f l~ure to 6 . ~ ~or th~ tYo comE~onent mixture. 1~ c~nnot be ~ CO~ nt~d that 'ch~ rea~:tlon is r~s~ns 1ble ~or the fact thAt tl-~ mola~ ~e~ ~rt o~ th~ ~lxtur~
rema~n~ ~table. Thl~ ~a~lllta~o~ the ~lHtlv~ly long ~torage perlod~ that c~n be aktafn~t3 u~lng th~ d~t control/bindlng mlxture, o~mpar~d to the'b~haviour o~ ~ l~re rnol~e~ under t~e sam~ con~tion~. In ~d~lon, tho mlxl q reduce3 tho vl~o~slty thu:s a1lowlng ~rob-em çrY~ ~umplns~ an~ ~aylng o~ the du~t contro1~b~ndIng ~ixture, ~Irlthout heatln , e~ren in 10w~r tom~ernt~Jrt:~ range~.
Tho applic~tlon onto the through ~l~tln ~lne du~t ~r~e granul~t~
can, dependlng on pr~per .pre~ug~ ane n DZ~cle ~electlon/ take pldce at roo3n te~s?craturq. In C0~ 18 ~n to other purely org~nlc dust ~inding ~ub~tanc~ preh~atlng 1~ n Dt necessarlly rqqulre~.
~he ~l~n-3llng o~ tho mlxtur~ ~9o~ not ~r ~s~nt any health or hyglene proble~o f or empl~oyoe~ ontc~ -t wlth lt .
~t wa:~ o~serve~l~ that the a~ldltlon o~ 0 .1$ and 1.0 ~ei~ht pert~ t, bas~d on the gr~n~lat~ to be S Fe~te~,. pxoved to he partlcularly ~ffe~tlve. In the c~e o~ It~ll fertllizbrs the amount o~ du~t controlfbi.'n~lng E~iXtUre rahge~ ~r~la 3 . 2 to O . 4 welght percent, ba~e~ on .the gx~nulate o be t~eate~ u~ed and the optlln~l ef~ctlvene~s ~chlevq~ h ~ ~re3cribed tolei~ance r~nge for the ra~d m~te~ ~a,l content ~St20 i ~ not ex~eeded in th~
aL)~ Atlon on Kall ~rtlllzer Slranulat:l c~

The du~t control ~o he qchloYe~ d~t ~ Dlned ln ~h~ ~ollo~lng mann~r:
~ample~ of ~he g~ ulat~ to be ~o n~ltl~n are fr~d o alny ~tt~ch¢d partic~les 'ch~ugh ;~tln q. Th~n the du~t control ~'bindlng ~ix'cu2~e td b~ t2st~ la ~vonly ~str1bute~ dn~
~p~ay~d onto tho 2dOg ~ les. A Eter the appllcAt~n ~f th~
mlxt~re, 1 pe~cent, b,a~e~ on the ~o~bln~d grhnu~alr w~l~ht, du~t ~ cO . ~ m~ D~d to th~ ~a ~ e~ an~ tlse comb~ne~
~mple~; ~re ~lxe~ n a ~ot~tln~ t ~; 1a~ for f lv~ ml~lu~
Ths re~ultln~ sa~p~s arc teste~ l~f~e:r ~ to~gç peLlod o~
l, 7 and 20 d~y~, ~y ~l.t1~ th~ ~ntlre ~ontent~ o~ the flask on an Alplne al~9tr~a~ ~ach 1n~ with a ~.063 mm sle~e, Th~ t~n~ perl~d mu~t b~ exactl y three mlnute~.
Afterwa~ he ~us~ la~en sl~Ye 5 Ellter p~per~ 19 ~eig~ed or ln th~ ca~e of ~ol~bl~ ~u~t, ~u~h a6 alkallne-~hloride, f lu~h~d out and th~ a~oun~ ~eter~ ne~ throu~h tltration .
The du~t control~l,n~ng p~r~ta 3e~ a~e calculAte~ ba6e~ on th~ re~ultlng 1~u~.e~.

In the ~xam~l~a sho~n ln th~ follo~ln~ t~bl~ 4 Kg o ~u~t control~bln~in~ mlxtur~ ~ro u~ @r Lnoo ~g o~ kal1um-~ulphate granulatQ ~ -O. ~
T~le: ~u~t ~ontrol ~el~it~ to unt~ea~e~ ~ample~ p~cent La~erzo~t - ~toro~e pcrlod~ Loesung = ~olutl~n, Mela~s~ - mola~se~ Nullprohe = Vntre~ to~ 3am~ Tage = d~y~

The r~ulto, ln co~p~rl~on to th~ un~ated ~p~e ~ho~ th~t V~L~
good du~t control~b1n~l~9 ls possL~le ~h~n the ~ixture.b~t~n molasses and salt ~o~ut~;~n l~o~ l~ the 50~ : 50~ ran~e. ~tray1ng from t~ optl~u~ r~tlc to, ~o~ ~x3mple 60~ molasse~ and ~0~ ~alt solutlon or vlse ~ers~ ~oe~ not ~lynl~ Ic~ntly a~ect ~ho e~ectl~enes~ o{ th~ pro~uct~. thU~ mak 1~ ~xt~eme a~cura~y ~n the m~xlng p~oce~s unncce~aary.
Th~ Pollow1ng ap~llc~tl~n exa~pl~ d~r~be th~ lnYentlon wlthout llmltlnq lt ~ny way. .
EXAMPL~
A ~ranulat~ m~nu~a~turedl ~y ~r~ gran pl4tlon ~n~ ~lfte~ in a o~1oY-Up p~oce~ ls ~tqre~ uncondltio ~ in a ~arehou~e.
l~ependent o~ the 3t~r~e ~ nn~ th, ~ or~ ln~epen~n~ o~ t~
re~lnlng mate~ials t~p~r~ture, the ml 3terlal~ p~lor to~ loa~lngO
i~ ~re~ pour~d into ~ ~lev~ to r~ove ~lpe du~t par~lclos. The next p~:OCe!S5 treat~ the ~ranula~e ~lth ~tu~t controlfbln~lng mixture prior to it b~ln~ d~o~lted ~nl to the tr2nspo~t conta~ner b~ the convey~r belt. The ~r~e ~ourln~ a ~ranul~t~ l~ spray~d wlth the 6u-t Qontrol/blnd~ng mlxt3r~ u~ln~ y noezle- located so r#

that th~ 3~ray con~ nclt)~e the p~urin~ ~nul~l:e on all ~
Thi6 18 ~ollowed by ~ redl~ tln~ z~ r tc) thorou5~hly ~ix th0 tr~a~ted gr;!~nul~ta . Th~ ~pray ~r~ ur~ th ~t 1~ u~ed r~n~s3 ~ 3 to 6 bar. .
The medIan ~c~mperature ~i~ th~ du~t ~ontro ~ nd~ mlxtu~e l~
roo~n tempe~ature, A mlxtur~ 1~ S0~ m~la~ 58~ an~ 50~ w~ter b~fi~d C~!12 ~o1~tlon coné~1nlny 3~0-~0 ,pR~cent C~ ~C12 or 50~ Mg~12 solutlon contalnlng 23-33 ~rc~n~C Mg~12 1 ~loyed ln an ~moun~
o~ 0. 3 ~eight ~erc~nt~ l:a~eid ~n th~ ~r~nu ~e to b~ ~ondltlorled.
~ ..
granulate ~n~nu~ctu~e~ by~ pre~8 ~r~nula lon and ~ ted in a fol10w-up proc~s~ i~ 3e~t ~i r~s:tly to 'che l~adlng proce~.
F`ol10~1ng the requ~r~ t,~n~ to r8~0Y~ lnæ du~t paxt~c1~ h~
condltioning m~erla1 1~ a~plle~ n ex nt~le 1. H~attng of th~
condltloning ~ater~a~ 1~ not Iequlr~d in h~3 Ca30 ~ue ~o the tempe~ure u~ the ~us'c propuceJ ~r~nulat , i~ a ~pr~y pressu~e of ~t least S to ~ bi~ is a vatlabl~.

Claims (8)

1. Procedure for the prevention of dust generation during the loading and transport of granular materials or pellets, especially fertilizer granulates, signified by the fact that a liquid mixture (dust control mixture) made up of an inorganic and an organic substance in water solution is added to the granulates. The substances are fully soluble in one another.
The organic substance preforms the dust binding function and the inorganic substance controls the moisture content of the mixture.

2. Procedure according to claim 1, signified by the fact, that the dust control/binding mixture is made up of molasses and a watery salt solution.

3. Procedure according to claim 2, signified by the fact that the salt solution is a CaC12 or NgC12 solution,

4. Procedure according to claim 1, signified by the fact, that the amount of dust control/binding mixture ranges from 0.15 to 1.0 weight percent of the materials to be treated.

5. Procedure according to claim 1, signified by the fact that the amount of dust control/binding mixture ranges from 0.2 to 0.4 weight percent of the materials to be treated, for Kali fertilizers.

6. Procedure according to claim 2, signified by the fact, that the mixture ratio, between molasses and CaC12 or MgC12 solution, ranges from 1: 0.5 to 1 : 2.

7. Procedure according to claim 3, signified by the fact, that the CaC12 solution has a concentration of 30-40% CaC12, and that the MgC12 solution has a concentration of 23-33% MgC12.

8. Procedure according to claim 1, signified by the fact, that the granulate is a Kalium-chloride fertilizer.