Conversion of alkali metal sulfate to the carbonate
US4309398A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 1, 1979 |
| Grant date | Jan 5, 1982 |
| Priority date | — |
| Expiry date | Oct 1, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01F11/00
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for converting potassium sulfate to potassium carbonate in which a mixture of potassium sulfate and calcium oxide are reacted at a temperature in the range of between about 700.degree. C. and about 800.degree. C. with a gaseous mixture having a minor amount of hydrogen and/or carbon monoxide in a diluent with the calcium oxide being present in an amount not greater than about 20 percent by weight of the potassium sulfate to produce an aqueous mixture of potassium sulfide, potassium bisulfide, potassium hydroxide and calcium sulfide and a gaseous mixture of steam and hydrogen sulfide. The potassium and calcium salts are quenched to produce an aqueous slurry of soluble potassium salts and insoluble calcium salts and a gaseous mixture of steam and hydrogen sulfide. The insoluble calcium salts are then separated from the aqueous solution of soluble potassium salts. The calcium salts are dried to produce calcium sulfide, calcium bisulfide and steam, and then, the calcium sulfide and calcium bisulfide are converted to the oxide and recycled. The soluble potassium salts are carbonated to produce potassium carbonate which is concentrated and the precipitated crystals separated. T…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.