US2973864A

US2973864A - Process for beneficiation of asphaltite material

Info

Publication number: US2973864A
Application number: US480289A
Authority: US
Inventors: Phillip E Mcgarry
Original assignee: International Minerals and Chemical Corp
Current assignee: International Minerals and Chemical Corp
Priority date: 1955-01-06
Filing date: 1955-01-06
Publication date: 1961-03-07
Anticipated expiration: 1978-03-07

Description

P. E. MCGARRY Filed Jan. 6, 1955 March 7, 1961 PRocEss FOR BENEFICIATION oF ASPHALTITE MATERIAL x Fusil, w

United States Patent() PROCESS FOR BENEFICIATION OF ASPHALTITE- MATERIAL Filed Jan. 6, 1955, Ser. No. 480,289

9 Claims. (Cl. 209-166) This invention relates to the benetication of uraniumbearing asphaltite ore. More particularly, it relates to the benecation of rock impregnated with bituminous material bearing uranium components. Still more particularly, it relates to a flotation process for dolomitic formations imprognated with uranium-bearing bitumens.

Asphaltite or bituminous rocks such as gilsonite, grahamite, wurtzilite, etc., are mined in various sections of the United States. VIn the western states there are numerous occurrences of dolomite formations containing uranium-bearing asphaltite material. The percentage of asphaltite material present in these ores is relatively small, generally less than about 10% and usually being .of the order of about 1% to about 5%. The uranium analyzed as U3O8 is present in quantities generally of the order of about 0.01% to about 0.06% by weight of the ore. Chemical recovery methods are not economically feasible for use on such'low grade uranium ore materials.

It is an object of this invention to provide a relatively inexpensive method of recovering the bituminous material and the uranium compounds associated therewith in a concentrated form.

It is still another object of this invention to provide an economical feasible method for preparation of an asphaltite concentrate useful as a feed material for chemical extraction processes for the recovery of uranium.

These and other objects will be apparent to those skilled in the art from the following description and a'ccompanying drawing which is a diagrammatic sketch of a beneciation process in accordance with the present invention.

Now it has been discovered that the asphaltite ore rnaterials can be subjected to ore otation operations in the absence of collectors and the gangue depressed soV that a beneciated uranium-bearing bitumen concentrate may be recovered.

The method as applied to dolomitic ore such as is foundV in New Mexico and Utah, for example a limestone ore impregnated with between about 1% and about 2% of bitumen, consists of crushing or grinding the ore to liberate the bitumen fraction, recovering an 'aqueous pulp, aerating the pulp with or without frother material present; or alternatively first aerating the pulp without frother present followed by treatment in the presence of frother material, conditioning the flotation concentrate with dispersant for nullifying the effect of contaminants on the limestone gangue, and subjecting the treated concentrate to aeration and agitation to separate limestone gangue from the final bitumen 'otation' concentrate. By frother material is meant a foam forming agent such as the alcohol, isobutyl carbinol or foam forming agent plus froth modifiers such as the frother pine oil plus the modifier such as fuel oil.

Run of the mine ore as received is subjected to jaw crushing, cone crushing, yrod milling and sizing operations to produce a pulp having particles of a size generally smaller than about l mesh or about 20 mesh.

N Alinatented Mar. 7, 1961 The mesh of grind Vfor sizing may shift somewhat depending upon the mesh size for liberation of the particle mixture, but the mesh of grind will seldom be coarser than above 4 mesh or finer than about 100 mesh.

The pulp of, for example, -20 mesh size particles is dewatered to the proper pulp density for conditioning, if it is to be reagentize'd, in suitable equipment such as Dorr classifiers, cyclones, Akins classifiers, and the like. Pulp is concentrated to a solids content generally in the range between about and about 75% solids by weight, and preferably to between about and about by weight.

if the pulp is to be subjected to agitation and aeration without reagentizing, then the dilute pulp is Vpassed to flotation apparatus or concentrated pulp is diluted to a solids content of about 20% to about 40% by weight, preferably to between about 25% and about 30% by weight. Generally, it is desirable for this flotation operation that the slurry `be at or near neutrality, preferably at a p-H in the range between about 5 and about 9.

-If a reagentized type flotation is to be effected, the frother material may be added to the dilute pulp, but preferably is added to a thick pulp. Effective frothers for this operation are hydrocarbons, such as fuel oil; alcohols, such as straight chain aliphatic alcohols of between yabout 4 and about 8 carbon atoms, for example, isobutyl carbinol hexyl alcohol and the like; and cyclic alcohols such as the terpineols, more commonly used in an impure form known as pine oil. Such frothing materials may be used individually or in mixtures, and are known in the trade by their chemical names or sold under tradenames such as American Cyanamids Aerofroth mixtures, Sharples Pentasol 23,V and the like.

Flotation of the bituminous material may be carried out in suitable apparatus such as Fagergren or Denver Y flotation machines, or equivalent apparatus arranged so as to have one or more sepa-ration stages.

From the flotation operation wherein the slurry is agitated and aerated there is recovered a bituminous concenv trate and a basically dolomite tail. The tail product usually is discarded. The concentrate from the first or rougher flotation is usually subjected toa cleaner or a second otation operation with or without change in the reagent conditions. `Concentrate from this'preliminary separationV operation is subjected to treatment with dispersants, one' of whose purposes'isV to clean the gangue material suring tank, Vthe Vslurry is partially freed of dispers-ants by Y dewatering and washing operations.` This rougher or f cleaner concentrate is subjected to one or more stages of recleaner operation to produce a final flotation concentrate. VFeed to this recleaner operation consists generally of concentrated slurry :adjusted to la solids content ofthe order o-f about 20% to about 30% solids. Tail products from the ore cleaner operation rnay be discarded; orif high enough in `U3O8 content the tail product may be re-" cycled, for example, to a prior-l'lotatiorrstage, for example, to the rougher. t The invention will be more clearly understood from thetollowingexample which is given by" way of illustration and without any intention that the in-1 vention be limited thereto. l

Example I Percent by Weight 96 Dolomite Asphaltite 1.5 to 2 Quartz 1 Mica 1 UaOa content 0.037

This ore was crushed, ground and size to produce a flotation feed approximately 100% of which passed through a 20 mesh standard screen. The -20 mesh material was mixed with water to produce a slurry of approximately 65% by weight solids content. The slurry was divided into four equal portions, A, B, C and D. Portion A after agitation in a conditioning tank for five minutes was diluted to a solids content of approximately 30% and introduced into aDenver subaeration flotation machine. For each 1000 parts by weight of dry solids fed to the flotation yoperation there was recovered 14 parts by weight of dry solids in the overflow or concentrate product. This concentrate analyzed 0.76% U3O8, which represents a recovery of approximately 30% of the U3O8 present in the feed.

Example Il Portion B from Example I Was agitated in the same conditioning tank for 5 minutes after there was added to the slurry 0.04 pound per ton of solids of pine oil. After conditioning, the conditioned concentrate was introduced into the same Denver subaeration flotation machine. For each 1000 parts by weight of dry solids feed there was recovered as a concentrate or overflow product 34 parts by weight of solids. This concentrate contains 0.67% UaOS, which represents a recovery of approximately 65% of thc U3O3 present in the feed.

Example III Portion C from Example I was introduced into the conditioning tank and 0.07 pound per ton of dry solids of pine oil and 0.6 pound per ton of Bunker C fuel oil were added. After agitation for 5 minutes, the conditioned slurry was diluted to a solids content of approximately 30% and introduced into the same Denver subaeration flotation machine. For each 1000 parts by weight Iof dry solids fed to the machine there was recovered 68 parts by weight of dry solids as a concentrate. This concentrate contained 0.44% U3O8, which represents a' recovery of approximately 86% of the USOS in the feed. This concentrate was introduced into the conditioning tank of Example I and 5 pounds of sodium hexametaphosphate added per ton of dry solids. After 5 minutes agitation in the conditioning tank the scrubbed slurry was dewatered and washed in an Akins` type classifier. The washed solids were slurried with water to have a solids content of approximately 30%, and the slurry was then floated in the same Denver subaeration flotation machine. For each 1000 parts by weight of dry solids fed to the initial flotation operation there was recovered l0 parts by weight of dry solids. This final concentrate contained 2.3% USOS, which represents a recovery of approximately 70% of the UaOS in the original feed. By drying and igniting this otation concentrate in a muffle furnace a product assaying approximately 22% U3O8 was produced.

.Having thus described the invention what I claim is:

1. A method for the beneficiation of uranium-bearing asphaltite ore which comprises comminuting the ore to liberation of the bituminous constituents, converting the liberated ore to an aqueous pulp and agitatiug and aerating the pulp in the absence of a collector to effect flotation of a bituminous concentrate, scrubbing the concentrate in slurry form with dispersants for bituminous material, washing the scrubbed slurry free of contaminants and dispersants and aeratng and agitating the scrubbed concentrate in the absence of a collector to effect flotation and to recover a second bituminous concentrate containing the uranimum constituents.

2. A method for the beneficiation of uranium-bearing asphaltite ore which comprises comminuting the ore to liberation of the bituminous constituents, converting the liberated ore to an aqueous pulp, conditioning the aqueous pulp in the absence of a collector with frothcr material, agitating and aerating the pulp to effect flotation of a bituminous concentrate, scrubbing the concentrate in slurry form with dispersants for bituminous material, washing the scrubbed slurry free of contaminants and dispersants and aerating and agitating the scrubbed concentrate in the absence of a collector to effect flotation and to recover a second bituminous concentrate containing the uranium constituents.

3. A method for the beneficiation of uranium-bearing asphaltite ore which comprises comminuting the ore to liberation of the bituminous constituents, converting the liberated ore to an aqueous pulp and agitating and aerating the pulp in the absence of a collector at s. pH in the range between about 5 and about 9 to effect otation of a bituminous concentrate, scrubbing the concentrate in slurry form with dispersants for bituminous material, Washing theA scrubbed slurry free of contaminants and dispersants and aerating and agitating the scrubbed concentrate in the absence of a collector to effect flotation and to recover a second bituminous concentrate contain ing' the uranium constituents.

4. A method for the beneficiation of uranium-bearing asphaltite impregnated limestone which comprises comminuting the ore to liberation of the bituminous constituents, converting the liberated ore to an aqueous pulp, conditioning the aqueous pulp with frother material, agitating and aerating the pulp in the absence of a collector to effect flotation of bituminous concentrate, scrubbing the concentrate in slurry form with dispcrsants for bituminous material, washing the scrubbed slurry free of contaminants and dispersants and aerating and agitating the scrubbed concentrate in the absence of a collector to effect flotation and to recover a second bituminous concentrate containing the uranium constituents.

5. A method for the beneficiation of uranium-bearing asphaltite ore which comprises comminuting the ore to liberation of the bituminous constituents, converting thc liberated ore to an'aqueous pulp, conditioning the aqucout pulp with frother material, agitating and aerating the pulp in the absence of a collector to effect flotation of a bituminous concentrate, scrubbing the concentrate in slurry form with sodium silicate, washing the scrubbed slurry free of contaminants and sodium silicate and act ating and agitating the scrubbed concentrate in the obsence of a collector to effect flotation `and to recover a second bituminous concentrate containing the uranium constituents.

6. A method for the benefcation of uranium-bearing asphaltite ore which comprises comminuting the ore to liberation of the bituminous constituents, converting the liberated ore to an aqueous pulp, conditioning the aqueous pulp with frother material, agitating and aerating the pulp inthe absence of a collector to effect flotation of a bituminous concentrate, scrubbing the concentrate in slurr;y form with sodium hexametaphosphate, washing the scrubbed slurry free of contaminants and sodium and sodium hexametaphosphate and aerating and agitating the scrubbed concentrate in the absence of a collector to effect flotation and to recover a second bituminous con` centrate containing the uranium constituents.

7. A method for the beneflcation of uranium-hearing asphaltite impregnated limestone which comprises cornminuting the' ore to -a size such that the largest particles fall in the range between about 10 mesh and about 20 mesh, converting the comminuted ore to an aqueous pulp, conditioning the aqueous pulp with about 0.04 pound of pine oil per ton of dry solids, agitating and aerating the pulp in the absence of a collector to eect otation of r a bituminous concentrate, scrubbing the concentrate in slurry form with between about 5 pounds and about 10 pounds of sodium hexametaphosphate per ton of dry solids, washing the scrubbed slurry free of contaminants and sodium hexametaphosphate and aerating and agitating the scrubbed concentrate in the absence of a co1- lector to effect otation and to recover a second bituminous concentrate.

8. A method for the benelciation of uranium-bearing asphaltite impregnated limestone which comprises comminuting the ore to a size such that the largest particles fall in the range between about mesh and about 20 mesh, converting the comminuted ore to an aqueous pulp, conditioning the aqueous pulp with about 0.07 pound of pine oil per 'ton of dry solids and about 0.6 pound of Bunker C fuel oil per ton of dry solids, agitating and aerating the pulp in the absence of a collector to effect otation of a bituminous concentrate, scrubbing the concentrate in slurry form with between about 5 pounds and about 10 pounds of sodium hexametaphosphate per t0n of dry solids, washing the scrubbed slurry free of contaminants and sodium hexametaphosphate and aerating and agitating the scrubbed concentrate in the absence of a collector to elect otation and to recover a second bituminous concentrate.

9. A method for the beneiiciation of uranium-bearing asphaltite impregated limestone which comprises cornminuting the ore to a size such that the largest particles fall in the range between about 10 mesh and about 20 mesh, converting the comminuated ore to an aqueous pulp, conditioning the aqueous pulp with about 0.07 pound per ton of pine oil and about 0.6 pound per ton of Bunker C fuel oil, agitating and aerating the pulp in the absence of a collector to effect otation of a bituminous concentrate, scrubbing the con- References Cited in the le of this patent UNITED STATES PATENTS 1,454,838 Borcherdt May 8, 1923 2,130,144 McClave Sept. 13, 1938 2,161,010 Breerwood June 6, 1939 2,363,315 Grothe Nov. 2l, 1944 2,389,727 Herkenhoi Nov. 27, 1945 2,469,422 Weinig May 10, 1949 2,507,012 Heilmann May 9, 1950 2,594,929 Howell Apr. 29, 1952 OTHER REFERENCES Denver Equipment Company Handbook, 1954, Denver Equipment Company, pages 582-609.

Taggart: Handbook of Mineral Dressing, 1945, pages 12-35.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION A Paten@ Nq, 2973e64 I March n i961 l Phillip ,E McGarry vIt is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column lv line 20 for "'imprognated" read am impregnated fm; column lI line 9Y strike out "in the absence of a collector and insert the same after vpulpm in line l()U seme column; line 64H strike outl "and sodium"o Signed and sealed this 19th day of September i961' (SEAL) Attest:

ERNEST w. SWIDER f DAVID L. LADD Attesting Officer Commissioner of Patents USCOMM-DC

Claims

1. A METHOD FOR THE BENEFICIATION OF URANIUM-BEARING ASPHALTITE ORE WHICH COMPRISES COMMINUTING THE ORE TO LIBERATION OF THE BITUMINOUS CONSTITUENTS, CONVERTING THE LIBERATED ORE TO AN AQUEOUS PULP AND AGITATING AND AERATING THE PULP IN THE ABSENCE OF A COLLECTOR TO EFFECT FLOTATION OF A BITUMINOUS CONCENTRATE, SCRUBBING THE CONCENTRATE IN SLURRY FROM WITH DISPERSANTS FOR BITUMINOUS MATERIAL, WASHING THE SCRUBBED SLURRY FREE OF CONTAMINANTS AND DISPERSANTS AND AERATING AND AGITATING THE SCRUBBED CONCENTRATE IN THE ABSENCE OF A COLLECTOR TO EFFECT FLOTATION AND TO RECOVER A SECOND BITUMINOUS CONCENTRATE CONTAINING THE URANIMUM CONSTITUENTS.