Process for removing particulate impurities from aqueous phosphoric acid
US4443421A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1982 |
| Grant date | Apr 17, 1984 |
| Priority date | — |
| Expiry date | Mar 16, 2002 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D37/00
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An emobodiment of a process for filtration of a slurry containing fine particles is a process comprising: PA0 (a) filtering phosphoric acid containing sludge-forming particulate impurities through a fabric filter whereby particulate impurities are separated from the phosphoric acid and retained on the surface of the fabric filter to form a filter cake comprising particulate impurities and entrained phosphoric acid; PA0 (b) contacting the filter cake with a wash fluid (e.g., water) to remove a major portion of the entrained phosphoric acid from the filter cake, thereby forming a washed filter cake; and, PA0 (c) removing the washed filter cake to expose a fresh surface of the fabric filter, for contacting with additional phosphoric acid containing particulate impurities. Preferably, the washed filter cake is removed by the introduction of pressurized air to the side of the fabric filter opposite the washed filter cake.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.