自贡地下卤水蕴含丰富的钠、镁、锂、溴、锶等，可用于生产原盐、镁盐和溴素等工业产品，是碱工业和盐产业重要的液态矿产资源。针对自贡地下卤水富含锶的特点和食盐生产工艺现状，开发了富锶食盐。通过优选草酸作为卤水净化剂，实现卤水除钙镁的同时保留更多的锶，优化的卤水净化工艺：将5.2 mL浓度为 0.7 mol/L的草酸以5 mL/min匀速滴加到45 ℃的100 mL卤水中，调节pH至8.0，搅拌反应30 min后加入0.3 mL质量浓度为2 g/L相对分子质量为800万的聚丙烯酰胺，静置1 h。优化工艺得到的净化卤水经高温蒸发后制得的食盐（以100 g干基计）中锶含量为37.5 mg，是现市售食盐中锶含量的20倍，锶盐其他各项指标均符合GB 2721—2015《食品安全国家标准 食用盐》，新工艺实现了自贡卤水锶的综合利用，也为市民提供富锶功能盐的选择。

Underground brine in Zigong contains rich sodium，magnesium，lithium bromide，strontium，etc.It can be used to produce raw salt，magnesium salt，bromine and other industrial products，which is an important liquid mineral resource for the alkali industry and salt industry.In response to the characteristics of rich strontium in underground brine in Zigong and the current status of salt production technology，strontium rich salt was developed.By optimizing oxalic acid as brine purifying agents，calcium and magnesium were removed from brine，and more strontium was retained.The optimized brine purification process was as follows：adding 5.2 mL of oxalic acid with concentration of 0.7 mol/L at a constant rate of 5 mL/min to 100 mL of brine at 45 ℃，adjusting the pH to 8.0，stirring for 30 min，adding 0.3 mL of polyacrylamide with mass concentration of 2 g/L and molecular weight of 8 million，allowing the final solution to stand for 1 h.The strontium content in the table salt（100 g dry basis） prepared by high-temperature evaporation of purified brine obtained by optimizing the process was 37.5 mg，which was 20 times of the strontium content in the currently available table salt.The strontium salts and other index requirements complied with the national standard（GB 2721—2015）.The new process realized the comprehensive utilization of strontium in Zigong brine，and also provided citizens with the choice of strontium rich functional salts.