Process of producing defluorinated product from low BPL phosphate rock
US4423015A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 4, 1982 |
| Grant date | Dec 27, 1983 |
| Priority date | — |
| Expiry date | Feb 4, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S71/03
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
In a process for producing a defluorinated product containing calcium, sodium and phosphorus, by calcination of a mixture of phosphate rock, with caustic soda, phosphoric acid and water, an improvement comprises maintaining the amount of phosphoric acid in the mixture such that the ratio of phosphorus in percentage by weight on a dry basis in said mixture-to-the phosphorus desired in percentage by weight in the calcined product is substantially equivalent to the ratio of the calcium in percentage by weight on a dry basis in the mixture-to-the calcium in percentage by weight in the calcined product. The process is especially useful where the phosphate rock has a bone phosphate of lime analysis of about 73% or less (e.g., about 71.5%), and also where the caustic soda is added to a mixture of phosphate rock and phosphoric acid prior to the addition of water.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.