Recovery of phosphorus from sludge
US4457845A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 11, 1982 |
| Grant date | Jul 3, 1984 |
| Priority date | — |
| Expiry date | Aug 11, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/907
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Phosphorus is recovered from the phosphorus sludge formed in the electrothermal production of phosphorus by contacting the sludge with a hydrophobic surface with sufficient force to cause the droplets of phosphorus in the sludge to coalesce and accumulate on the surface, from which it can become detached in the form of large phosphorus drops. One such recovery process involves contacting the sludge, under hydrostatic or other pressure, with a porous membrane formed of a hydrophobic material, through which passes coalesced phosphorus from the sludge, the water and the bulk of the impurities of the sludge being restrained against passage. Other coalescing procedures involve shearing the sludge between sliding hydrophobic surfaces and passing the sludge between hydrophobic surfaces in rolling contact. Typical hydrophobic materials are polyethylene, polypropylene, and rubber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.