Carbothermic reduction of high-grade celestite ore to manufacture strontium carbonate

The conversion of celestite (SrSO4) to strontium sulphide (SrS) by the carb othermic reduction process was investigated as a route for the production o f SrCO3 from high-grade Turkish celestite ores. Experiments were conducted in the temperature range 900-1400 degrees C and metallurgical-grade coke wa s used as the reducing agent. The effects of reduction temperature, amount of carbon and roasting time were studied. The products of reaction (black a sh) were examined, mainly with the use of X-ray diffraction and name atomic absorption spectrometry. The results include data on recoverable Sr obtain ed as strontium carbonate precipitate. The conversion reaction is complete at 1300 degrees C, and it begins at lower temperatures. In addition to sulp hate-sulphide conversion, all alkali earth metals found in the ore can be t ransformed to carbides in the process of reduction, especially when the roa sting time and amount of carbon added to concentrate are increased. The red uction reaction seems to be very fast and it is concluded that the manufact ure of SrCO3 is feasible from the roasted product.