Production of hydrofluoric acid from phosphate-containing fluorspar
US4078047A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 30, 1976 |
| Grant date | Mar 7, 1978 |
| Priority date | — |
| Expiry date | Dec 30, 1996 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B7/192
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
In the reaction of phosphate-containing fluorspar with sulphuric acid to produce gaseous hydrofluoric acid, withdrawing the hydrofluoric acid and condensing it, the improvement which comprises adding to the fluorspar a reactive iron compound in an amount approximately equivalent to the phosphate content whereby the phosphate content of the condensed hydrofluoric acid is markedly diminished. The reactive iron compound can be contained in another fluorspar which is blended in the first fluorspar in the requisite amount and/or it can be an iron oxide, fluoride or sulphate, or a hydrated or hydratable iron compound added to the phosphate-containing fluorspar in about 0.2 to 5% by weight calculated as Fe.sub.2 O.sub.3 content and based on the fluorspar.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.