Ball milling induced reduction of SrSO4 by Al
- Authors: Setoudeh, N. , Welham, Nicholas
- Date: 2011
- Type: Text , Journal article
- Relation: International Journal of Mineral Processing Vol. 98, no. 3-4 (2011), p. 214-218
- Full Text: false
- Reviewed:
- Description: The reduction of celestite concentrate to SrS using Al has been shown to be induced by mechanical activation. A thermodynamic appraisal showed that the reaction between SrSO4 and Al is highly exothermic and should be self-sustaining. XRD analyses showed that reaction started only after milling for an induction time of 30-35 min, after induction only product peaks were present. Increasing milling time up to 60 min had no significant effect other than refining the crystallite size. The aluminium product was not Al 2O3 as expected but mixed phases such as Sr 3Al32O51, SrAl4O7 and SrAl2O4 which were thought to be formed by an adventitious oxidation process. © 2010 Elsevier B.V. All rights reserved.
Dry mechanochemical conversion of SrSO4 to SrCO3
- Authors: Setoudeh, N. , Welham, Nicholas , Azami, S. M.
- Date: 2010
- Type: Text , Journal article
- Relation: Journal of Alloys and Compounds Vol. 492, no. 1-2 (2010), p. 389-391
- Full Text: false
- Reviewed:
- Description: 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. © 2009 Elsevier B.V. All rights reserved.