Process for the treatment of a calcium aluminophosphate
AssigneeGroupement Franco-Senagalais d'Etudes et de Recherches Industrielles
InventorsClaude Magnier, Jean Grosbois
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Abstract
A process for treating a rock essentially constituted by calcium aluminophosphate, comprising the treatment of the ground rock with a concentrated sulfuric acid in stoichiometric excess with respect to calcium and aluminum, at a temperature of above about 120.degree. C., for a time between a few minutes and about 5 hours, followed by controlled water take-up. Subsequently, a residue containing substantially all the calcium and the aluminum of the rock and a solution of the acids serving to digest a tricalciumphosphate charge are separated. The process is particularly suitable for the treatment of Thies phosphate ore.
Claims19
A process for the treatment of phosphatic rock, essentially constituted by calcium aluminophosphates and containing iron and other cations in small concentrations, which process comprises:
- (a) subjecting the ground rock to calcination treatment in the presence of concentrated sulfuric acid in stoichiometric excess with respect to the aluminum, calcium and iron contained in the starting rock for a time between about a few minutes and about five hours and at a temperature above about 120.degree. C. to obtain a paste which contains aluminum sulfate and iron sulfate in substantially anhydrous form, phosphoric acid and sulfuric acid;
- (b) subjecting the paste obtained in step (a) above to controlled take-up by means of water or an aqueous solution comprising phosphoric or sulfuric acid or both to obtain two phases, the first phase being a solid residue substantially containing aluminum, calcium and iron from the starting rock and the second phase comprising aqueous phosphoric and sulfuric acid solution;
- (c) separating the second phase obtained in step (b) from the first phase obtained in step (b) to obtain an aqueous solution comprising a mixture of sulfuric and phosphoric acid.
Dependencies are inferred from the claim text.