Method and apparatus for sequencing-batch purification of potassium nitrate from solid waste produced by glass-strengthening process
US8956424B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 17, 2013 |
| Grant date | Feb 17, 2015 |
| Priority date | — |
| Expiry date | May 19, 2033 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01D9/16
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Provided is a method and an apparatus for purifying potassium nitrate from the solid waste produced by a chemical glass-strengthening process. In the method, the solid waste is melted into a liquid waste at first. Potassium nitrate of various purity grades can be obtained by batch processing the liquid waste through stepwise cooling processes of cooling the liquid waste to a first temperature facilitating the potassium nitrate contained in the liquid waste to be crystallized at a first rate and then cooling the liquid waste to a second temperature close to the freezing point of the potassium nitrate at a second rate that is slower than the first rate. The recovered potassium nitrate from the solid waste can be recycled and reused.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.