Rationalization of the up-grading circuit of celestite for advanced applications

The conversion of celestite into other strontium compounds, mainly strontium carbonate, is a necessary step for many industrial applications. However, the impurities need to be removed to achieve a suitable celestite grade (> 90% SrSO4) for the conversion process.Therefore, this paper is aimed at celestite separation from calcite using gravity separation (i.e., jig and shaking table). The jig was used to deal with coarse sizes (− 15 + 2.0 mm) while shaking table was used to deal with finer sizes (− 0.5 + 0.080 mm) or cleaning the jig tailings after further regrinding to − 0.5 mm. Moreover, the shaking table separation was evaluated in terms of its operating parameters using statistical design of experiments. Starting from the primary crushed − 0.5 + 0.080 mm fraction contains 44.91% SrO (79.58% SrSO4), a celestite concentrate 51.88%SrO (91.93% SrSO4) was produced at optimum conditions; i.e., 25%, 3 cm, 25 l/min, and 6 degree for pulp density, stroke length, water flow rate, and table slope, respectively.

Figure optionsDownload as PowerPoint slideAlthough celestite is the most common strontium mineral, it cannot be used directly in its sulfate form. The celestite conversion into other strontium compounds needs impurities removal. Celestite beneficiation from calcite impurities depends on their textural interaction. The microscopic investigation revealed that the liberation increases with particle size fineness which explains the higher recovery of tabling than jigging.