# US 4,393,028 A · Method of removing uranium from a slurry containing molybdenum

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- Number: US 4,393,028 A
- Document ID: US4393028A
- Status: Granted
- Kind: A
- Application number: 06/273,175
- Filed: 1981-06-12
- Granted: 1983-07-12
- Earliest claimed: 1981-06-12
- Assignees: Wyoming Mineral Corporation
- Inventors: Thomas J. Crossley
- Web page: https://patentgrep.com/patent/US4393028A

## CPC

- C01G 39/00: Compounds of molybdenum
- C22B 34/34: Obtaining molybdenum {(treatment or purification of solutions by adsorption on solids C22B3/24, by liquid-liquid extraction C22B3/26, by ion-exchange extraction C22B3/42; preparation of molybdenum involving liquid-liquid extraction, adsorption or ion-exchange C01G39/003)}
- C22B 60/0278: {by chemical methods (C22B60/0256, C22B60/026, C22B60/0265 take precedence)}
- C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20)
- C22B: PRODUCTION AND REFINING OF METALS (electrolytic C25); PRETREATMENT OF RAW MATERIALS

## Abstract

Disclosed is a method of removing uranium from a slurry containing a water-insoluble molybdate and a Group II element, usually calcium. The pH of the slurry is raised with an alkali metal hydroxide and maintained at a level sufficiently high to solubilize insoluble molybdenum compounds. This will generally require a pH of at least 10 which can be achieved by adding sodium hydroxide. Carbonate ion is then added to the slurry in an amount at least sufficient to precipitate the cation of the insoluble molybdenum compound. And finally, the solid portion of a slurry, which now contains calcium carbonate and sodium uranate, is separated from the liquid portion, which contains a soluble molybdenum compound.

## Claims

### Claim 1

A method of separating uranium from molybdenum contaminated with said uranium comprising:
(1) preparing an aqueous slurry of said uranium contaminated molybdenum which comprises calcium, about 40 to about 60% of a water-insoluble molybdate, and about 0.1 to about 0.6% uranium calculated as U.sub.3 O.sub.8 ;
(2) raising and maintaining the pH of said slurry about 10 with an alkali metal hydroxide;
(3) adding sufficient carbonate ion to said slurry to precipitate calcium carbonate and calcium uranate; and
(4) separating said precipitated calcium carbonate and calcium uranate from the liquid portion of said slurry, which contains said molybdenum.

### Claim 2 (depends on 1)

A method according to claim 1 wherein the source of said carbonate ion is carbon dioxide.

### Claim 3 (depends on 1)

A method according to claim 1 wherein the source of said carbonate ion is sodium carbonate.

### Claim 4 (depends on 1)

A method according to claim 1 wherein said alkali metal hydroxide is sodium hydroxide.

### Claim 5 (depends on 1)

A method according to claim 1 wherein said pH is raised above 12.

### Claim 6 (depends on 1)

A method according to claim 1 wherein said water-insoluble molybdate is calcium molybdate.