Conversion process for strontium sulfate in carbonate rich celestite ores to strontium carbonate using sodium carbonate in an air/vapor-lift loop reactor

摘要

This invention relates to a low energy hydrometallurgical process for the production of strontium carbonate of chemical and glass grade from carbonate rich celestite ores typically having around 28% combined strontianite, calcite, dolomite and other carbonates. This process avoids negative environmental impact usually associated to calcining technology and involves fewer processing stages than prior art hydrometallurgical processes. Thus, in two stages which provide: (1) the acid wash of the celestite ore in an acid medium to eliminate carbonates present other than strontium carbonates and (2) the conversion of the thus enriched celestite to strontium carbonate in an air/vapor-lift loop reactor using a sodium carbonate aqueous medium, a step permitting recovery of sodium sulfate as a by-product. Thus, an almost complete conversion of the strontium sulfate present in the enriched ore is achieved.