# US 2016/0355406 A1 · Methods To Recover Cesium Formate From A Mixed Alkali Metal Formate Blend

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- Number: US 2016/0355406 A1
- Document ID: US20160355406A1
- Status: Published application
- Kind: A1
- Application number: 15/244,095
- Filed: 2016-08-23
- Published: 2016-12-08
- Earliest claimed: 2013-12-03
- Assignees: Cabot Corporation
- Applicants: Cabot Corporation
- Inventors: Bart F. Bakke
- Web page: https://patentgrep.com/patent/US20160355406A1

## CPC

- C01D 17/003: {Compounds of alkali metals}
- C01D 5/06: Preparation of sulfates by double decomposition
- C01D 17/00: Rubidium, caesium or francium compounds
- C07C 51/02: from salts of carboxylic acids
- C07C 51/43: by change of the physical state, e.g. crystallisation
- C07C 51/487: by treatment giving rise to chemical modification (by chemisorption C07C51/47)
- C09K 8/05: containing inorganic compounds only, e.g. mixtures of clay and salt
- C22B 3/44: by chemical processes (treatment or purification of solutions by liquid-liquid extraction C22B3/26, by ion-exchange extraction C22B3/42)
- C22B 3/46: by substitution, e.g. by cementation
- C22B 26/10: Obtaining alkali metals
- C09K 2208/00: Aspects relating to compositions of drilling or well treatment fluids
- C01D: COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts of peroxyacids C01B15/00; sulfides C01B17/22; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds other than ammonia and cyanogen, containing nitrogen and other non-metals C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; phosphides 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; cyanides C01C3/08; salts of cyanic acid C01C3/14; salts of cyanamide C01C3/16; thiocyanates C01C3/20)
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C22B: PRODUCTION AND REFINING OF METALS (electrolytic C25); PRETREATMENT OF RAW MATERIALS

## Abstract

Methods to recover or separate cesium formate or rubidium formate or both from a mixed alkali metal formate blend are described. One method involves adding cesium sulfate or rubidium sulfate to the mixed alkali metal formate blend in order to preferentially precipitate potassium sulfate from the mixed alkali metal formate blend. Another method involves adding cesium carbonate or cesium bicarbonate or both to preferentially precipitate potassium carbonate/bicarbonate and/or other non-cesium or non-rubidium metals from the mixed alkali metal blend. Further optional steps are also described. Still one other method involves converting cesium sulfate to cesium hydroxide.

## Claims

### Claim at position 1

1-60. (canceled)

### Claim 61

A method to convert at least a portion of cesium sulfate in solution to cesium hydroxide in said solution, said method comprising adding potassium hydroxide to said solution to form potassium sulfate precipitate and cesium hydroxide in said solution; and
separating at least a portion of said potassium sulfate precipitate from said solution to obtain a resulting solution containing cesium hydroxide.

### Claim 62 (depends on 61)

The method of claim 61, further comprising a) reducing water content from said resulting solution in order to precipitate additional potassium sulfate and b) separating at least a portion of said additional potassium sulfate precipitate from said resulting solution, and optionally repeating a) and b) one or more times.

### Claim 63 (depends on 62)

The method of claim 62, wherein said removing water is achieved by heating said resulting solution.

### Claim 64 (depends on 62)

The method of claim 62, wherein said repeating of a) and b) occurs at least once and said removing water is achieved by heating.

### Claim 65 (depends on 61)

The method of claim 61, wherein said solution containing said cesium sulfate is at a temperature or raised to a temperature of about 50° C. or higher, so as to preferentially precipitate potassium sulfate and form cesium hydroxide in said solution.

### Claim 66 (depends on 61)

The method of claim 61, further comprising a) heating said resulting solution to a temperature of from about 50° C. to boiling point of said resulting solution in order to reduce water content and precipitate additional potassium sulfate and b) separating at least a portion of additional potassium sulfate precipitate from said resulting solution, and repeating a) and b) at least once.

### Claim 67 (depends on 61)

The method of claim 61, wherein said cesium sulfate in solution comprises from about 1 wt % to about 100 wt % cesium sulfate based on the weight of alkali metal salts present in said solution.

### Claim 68 (depends on 61)

The method of claim 61, wherein said cesium sulfate in solution comprises from about 60 wt % to about 99 wt % cesium sulfate based on the weight of alkali metal salts present in said solution.

### Claim 69 (depends on 61)

The method of claim 61, wherein said cesium sulfate in solution comprises from about 90 wt % to about 99 wt % cesium sulfate based on the weight of alkali metal salts present in said solution.

### Claim 70 (depends on 61)

The method of claim 61, wherein said potassium hydroxide is added in an amount to react with from about 10 wt % to 100 wt % of cesium sulfate present in said solution.

### Claim 71 (depends on 61)

The method of claim 61, wherein said potassium hydroxide is added in an amount to react with from 80 wt % to 99.5 wt % of cesium sulfate in said solution.

### Claim 72 (depends on 61)

The method of claim 61, wherein said potassium hydroxide is added in an amount to react with from 95 wt % to 99 wt % of cesium sulfate in said solution.

### Claim 73 (depends on 61)

The method of claim 61, wherein said potassium hydroxide is added as one addition to said solution.

### Claim 74 (depends on 61)

The method of claim 61, wherein said potassium hydroxide is added as multiple additions at separate times to said solution.

### Claim 75 (depends on 61)

The method of claim 61, wherein said adding is continuous, semi-continuous, or by single addition prior to said separating.

### Claim 76

A method to convert at least a portion of cesium sulfate or rubidium sulfate or both in solution to cesium hydroxide or rubidium hydroxide or both in said solution, said method comprising adding potassium hydroxide to said solution to form potassium sulfate precipitate and cesium hydroxide or rubidium hydroxide or both in said solution; and
separating at least a portion of said potassium sulfate precipitate from said solution to obtain a resulting solution containing cesium hydroxide or rubidium hydroxide or both.

### Claim 77 (depends on 76)

The method of claim 76, further comprising a) reducing water content from said resulting solution in order to precipitate additional potassium sulfate and b) separating at least a portion of said additional potassium sulfate precipitate from said resulting solution, and optionally repeating a) and b) one or more times.

### Claim 78 (depends on 61)

The method of claim 61, wherein said method is conducted in the absence of a barium compound.

### Claim 79 (depends on 62)

The method of claim 62, wherein said method is conducted in the absence of a barium compound.

### Claim 80 (depends on 76)

The method of claim 76, wherein said method is conducted in the absence of a barium compound.

### Claim 81 (depends on 77)

The method of claim 77, wherein said method is conducted in the absence of a barium compound.