METHOD, APPARATUS AND USE OF CHELATING AGENTS FOR THE PURIFICATION OF CALCIUM SULPHATE

摘要

A chemical process for the purification of CaSO4 utilises the ability of an aqueous solution of a chelating agent to selectively dissolve CaSO4, in that the initial extraction can be carried out at certain pH and CaSO4 can be recovered by titration to a different pH (usually a lower pH) following a mechanical treatment, such as centrifugation or filtration, to separate the aqueous chelate solution from insoluble material. Also claimed are an apparatus and the use of chelating agents therefor.