Abstract:

With the rapid development of electronics,nonferrous metals,aerospace and other industries,the market demand for strontium and strontium salts is increasing.With strontium-containing industrial waste residue from the production of strontium carbonate by carbon reduction as raw material,hydrochloric acid and ammonium chloride as leaching agents,the effects of leaching time,leaching temperature and the amount-of-substance ratio of hydrochloric acid to ammonium chloride on the leaching rate of strontium in the waste residue were investigated.On the basis of single factor experiment,Box-BehnKen response surface analysis method with 3 factors and 3 levels was used to optimize the leaching process of strontium,and the optimal process conditions were determined.Results showed that: under the optimal conditions of amount-of-substance ratio of hydrochloric acid to ammonium chloride ratio of 4.32,leaching time of 104 min and leaching temperature of 33 ℃,the average value of strontium leaching rate was 95.15%,the standard deviation was 0.146 2,the relative standard deviation was 0.153 7% and the relative error was only 0.17%.The order of influence of the selected factors on strontium extraction rate from big to small was as follows：extraction time,amount-of-substance ratio of hydrochloric acid to ammonium chloride and extraction temperature.It was provided a reference for the recovery and utilization of strontium resources in strontium residue.

Key words: strontium carbonate, strontium slag, leaching process