The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 26, 2020
Filed:
Jun. 22, 2017
Prayon Technologies, Engis, BE;
Thomas Henry, Heers, BE;
Tibaut Theys, Faux-les-Tombes, BE;
PRAYON TECHNOLOGIES, Engis, BE;
Abstract
A method for preparing calcium sulphate comprising a production of DCP by the attack of a source of phosphate by an acid, a digestion of the isolated DCP by the sulphuric acid under conditions giving rise to the formation of a first slurry of gypsum suspended in an acidic aqueous phase having a content of free SOequal to or less than 1.5% and a content of free PO, a conversion of at least part of said first slurry by heating to a temperature greater than 80° C. and potentially by adding sulphuric acid, with solubilisation of the gypsum crystals and recrystallisation of the solubilised calcium sulphate in a second slurry of α-calcium sulphate hemihydrate crystals suspended in an aqueous phase based-on phosphoric acid, wherein the content of free SOis less than 10% by weight, and a separation between said aqueous phase and a filter cake based on particularly pure α-calcium sulphate hemihydrate.