Preliminary laboratory studies on Eppawela apatite-II

Investigations carried out earlier showed that the phosphate in Eppawela apatite can be converted into a citric acid soluble form by treatment with soda ash. In the present series of experiments apatite obtained from the grinding plant at Eppawela was used. Calcination of this powdered apatite at 1400⁰C complete conversion of P₅O₅ to citric acid soluble form was obtained. The chemical and the energy dispersive spectrometer analyses of the powdered sample of apatite showed that it contains alumina, iron oxide and silica as main impurities. These impurities favoured the conversion of P₅O₅.in apatite to citric soluble form. Treatment of pure apatite with red clay containing alumina, iron oxide and silica also showed a positive effect on the conversion of P₅O₅ to citric soluble form.