Method for producing soluble potassium sulfate
US10981838B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 2017 |
| Grant date | Apr 20, 2021 |
| Priority date | — |
| Expiry date | Nov 13, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/80
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Method for producing soluble potassium sulfate by recrystallization of crude potassium sulfate wherein the crude potassium sulfate contains an amount of potassium, calculated as K2O, of about 15 wt % or higher, and the resulting potassium sulfate crystalline material conforms with the following characteristics: the amount of insoluble material is less than about 0.05 wt %, a 1 wt % solution of the potassium sulfate has a pH below about 6, and/or 1 pH unit lower than the pH of the crude potassium sulfate, the fraction obtained after crystallization has an average particle size within the following parameters: (i) d90<about 0.6 mm, (ii) d10>about 0.02 mm, and (iii) dust amounts to about 0.4 wt % or less, whereby the resulting potassium sulfate contains more than 51% potassium, calculated as K2O.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.