Dry mechanochemical conversion of SrSO4 to SrCO3

The effect of milling time on the dry conversion of celestite, SrSO4, to SrCO3 using sodium carbonate in a planetary type ball mill was investigated. After milling, the powders were leached in distilled water at room temperature and the solids then washed with 1 N HCl to separate the products. X-Ray diffraction analysis showed that SrSO4 started to transform to SrCO3 within 10 min of milling and the extent of conversion increased with milling time reaching >90% after 30 min. A <99% conversion of celestite to SrCO3 was obtained in 30 min by increasing the molar ratio of Na2CO3:SrSO4 to 1.3:1. (C) 2009 Elsevier B.V. All rights reserved.