Direct Conversion of Celestite to SrCO3 by Wet Milling

Effect of the high energy ball milling on the direct conversion of celestite to strontium carbonate (SrCO3) was studied. Celestite ore was ground by a planetary ball mill with sodium carbonate (Na2CO3) solution. Experimental study carried out to determine the effects of milling time (5, 10, 15, 30, 60, and 120 min) and Na2CO3 concentration (1, 1.25, 1.5, and 2 M) on the precipitation efficiency. Volume of carbonate solution was calculated for the stoichiometric amount of sulfate in celestite and solid material/ball weight ratio is selected 1/10 as constant. After filtering, washing and drying the precipitated SrCO3 sludge was analyzed by X-Ray Diffractometer (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The conversion rate of celestite to SrCO3 increased systematically with extending milling time. The strontium carbonate in the product can be concentrated up to 99.8% by 120 min wet milling of celestite in 2 M Na2CO3 solution.