# US 7,744,845 B2 · Synthesis of lithium zirconate

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 7,744,845 B2
- Document ID: US7744845B2
- Status: Granted
- Kind: B2
- Application number: 12/064,274
- Filed: 2006-08-25
- Published: 2008-09-18
- Granted: 2010-06-29
- Earliest claimed: 2005-08-25
- Assignees: Magnesium Elektron Limited
- Inventors: Hazel Stephenson
- Web page: https://patentgrep.com/patent/US7744845B2

## CPC

- B01J 20/28078: {Pore diameter}
- B01J 20/0211: {Compounds of Ti, Zr, Hf}
- B01J 20/041: {Oxides or hydroxides}
- B01J 20/06: comprising oxides or hydroxides of metals not provided for in group B01J20/04
- B01J 20/08: comprising aluminium oxide or hydroxide; comprising bauxite
- B01J 20/28057: {Surface area, e.g. B.E.T specific surface area}
- B01J 20/28069: {Pore volume, e.g. total pore volume, mesopore volume, micropore volume}
- B01J 20/3078: {Thermal treatment, e.g. calcining or pyrolizing}
- B01J 20/3433: {of sorbents or filter aids other than those covered by B01J20/3408 - B01J20/3425}
- B01J 20/3483: {by thermal treatment not covered by groups B01J20/3441 - B01J20/3475, e.g. by heating or cooling}
- B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites
- C01G 25/00: Compounds of zirconium
- C04B 35/48: based on zirconium or hafnium oxides, zirconates, {zircon} or hafnates
- C04B 35/62675: {characterised by the treatment temperature}
- B01J 2220/42: Materials comprising a mixture of inorganic materials (materials coated or impregnated on a carrier B01J20/32)
- C01P 2002/72: by d-values or two theta-values, e.g. as X-ray diagram
- C01P 2004/64: Nanometer sized, i.e. from 1-100 nanometer
- C01P 2006/12: Surface area
- C01P 2006/14: Pore volume
- C01P 2006/16: Pore diameter
- C04B 2235/3203: Lithium oxide or oxide-forming salts thereof
- C04B 2235/3206: Magnesium oxides or oxide-forming salts thereof
- C04B 2235/3217: Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
- C04B 2235/3225: Yttrium oxide or oxide-forming salts thereof
- C04B 2235/3418: Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint
- C04B 2235/442: Carbonates
- C04B 2235/5409: expressed by specific surface values
- C04B 2235/5436: micrometer sized, i.e. from 1 to 100 micron
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- 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)
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS

## Abstract

A process is disclosed for the preparation of lithium zirconate and doped lithium zirconates for use as regenerable carbon dioxide sorbants by wet mixing zirconium hydroxide with lithium carbonate and then calcining the mixture. Due to the improved physical properties resulting from the disclosed preparation process, the lithium zirconates produced by this process are capable of absorbing carbon dioxide at high rates and in large amounts.

## Claims

### Claim 1

A process for the production of lithium zirconate comprising the steps of:
wet mixing zirconium hydroxide with lithium carbonate, and
calcining the mixture to form undoped said lithium zirconate having a formula, Li2ZrO3, or doped said lithium zirconate having a formula, LinM′2-nZr1-2nO3, where n is at least 0.01 and M′ is one or more of Al, Na, Si, K, Mg and Y, and said doped and undoped lithium zirconate is in at least one of a tetragonal or monoclinic phase.

### Claim 2 (depends on 1)

A process as claimed in claim 1 wherein the wet mixing is effected in an aqueous medium.

### Claim 3 (depends on 1)

A process as claimed in claim 1 wherein the zirconium hydroxide is doped with a hydroxide of one or more of potassium, magnesium, sodium, lithium, yttrium, aluminum and silicon before being mixed with said lithium carbonate.

### Claim 4 (depends on 1)

A process as claimed in claim 1 wherein one or more of potassium, magnesium, sodium, lithium, yttrium, aluminum and silicon salts are added during the mixing of zirconium hydroxide and lithium carbonate, the salts being capable of undergoing pyrolysis to form their corresponding oxides.

### Claim 5 (depends on 4)

A process as claimed in claim 4 wherein the salts are carbonate salts.

### Claim 6 (depends on 1)

A process as claimed in claim 1 wherein the calcination temperature is at least 700° C. but less than 800° C.

### Claim 7 (depends on 6)

A process as claimed in claim 6 wherein the calcination temperature is at least 775° C., but less than 800° C.

### Claim 8 (depends on 1)

A process as claimed in claim 1 wherein conditions of said calcining produce said doped or undoped lithium zirconate having a total pore volume of at least 0.002 cm3/g.

### Claim 9 (depends on 8)

A process as claimed in claim 8 wherein said conditions of said calcining produce said doped or undoped lithium zirconate capable of absorbing 4.85 mol/kg of carbon dioxide.

### Claim 10 (depends on 8)

A process as claimed in claim 8 wherein said conditions of said calcining produce said doped or undoped lithium zirconate having a surface area of at least 0.49 m2/g.

### Claim 11 (depends on 8)

A process as claimed in claim 8 wherein said conditions of said calcining produce said doped or undoped lithium zirconate having a mean pore diameter of less than 75 nm.

### Claim 12 (depends on 1)

A process as claimed in claim 1 comprising drying the mixture prior to said calcining.