A novel method for the preparation of strontium carbonate from celestite ore has been investigated. The ore is reduced by brown coal at a temperature of 1000 deg C for a period of 3 h. The reduced product is leached with water at a liquid solid ratio of 3 is to 1 at 90 deg C and the slurry is then leached with hydrochloric acid at a solid : liquid ratio of 2 is to 1. By controlling the pH at 1.5-2 and adding 20 percent H_2O_2 at the rate of 0.5 dm~3/m~3 of solution the oxidation process HS~-S~o is accomplished. Barium is precipitated with dilute sulphuric acid; and more than 90 percent Ca~(2+) + Mg~(2+) (and Fe) is removed when the pH is increased to 12. Addition of 1.2 times the theoretically required amount of NH_4HCO_3 at a solution strength of 2 mol/1 at 60 deg C and at pH in the range 9-11 results in the precipitation of SrCO_3. The precipitate is washed and dried at 220-250 deg C. The proposed flowsheet is simple, has low consumption of acid and alkaline reagents, gives a high recovery of strontium and accepts a wide range of raw material.
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