Method of producing phosphorus pentoxide in a kiln with reduced carbon burnout
US4397826A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 10, 1982 |
| Grant date | Aug 9, 1983 |
| Priority date | — |
| Expiry date | May 10, 2002 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B25/12
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for producing phosphorus pentoxide from phosphate ore includes the steps of mixing phosphate ore containing silica with solid carbonaceous material and a silica fluxing agent to form a feed mixture and thereafter forming the feed mixture into pellets. Alternatively, pellets may be formed using phosphate ore containing silica and carbonaceous material which are then coated with a silica fluxing agent. The pellets are heated by exposure to radiation eminating from an oxidation zone within a kiln to a temperature enabling the silica fluxing agent to promote melting of the silica proximate to surface areas of the pellet in order to seal internal portions of the pellet from the oxidizing zone and thereby reduce premature oxidation of the carbonaceous material in the pellet. Thereafter the pellets are heated to a temperature sufficient to reduce the phosphate in the pellets by reaction with the solid carbonaceous material to form elemental phosphorus vapor. Sufficient oxygen-containing gas is introduced into the kiln to cause oxidation of the elemental phosphorus vapor within the oxidation zone to produce phosphorus pentoxide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.