以吉兰泰南线船采二层盐为原料,用氨碱废液和淡水混配后溶采反应脱除硫酸根并生产纯碱用液体盐。采用中试研究优化工艺条件,在中试最佳工艺条件的基础上,确定了聚丙烯酰胺对二水硫酸钙沉降效果的影响。中试研究结果表明最佳工艺条件为:洗渣工序氨碱废液与淡水的体积比为1∶9、洗渣停留时间为2.5 h、制卤停留时间为3 h,反应罐二级脱硫工序n（硫酸根）∶n（钙离子）为1∶0.75、停留时间为5 min。二次沉降过程中聚丙烯酰胺的添加量为62.5 mg/L时,二水硫酸钙的沉降效果较好,液体盐透光率≥80%。优化工艺条件下可达到企业制碱用液体盐标准,其中钙离子的质量浓度≤2 g/L、硫酸根的质量浓度≤5 g/L、氯化钠的质量浓度≥305 g/L,同时采用该工艺能够实现资源综合利用。

Taking the second layer salt from the ship of Jilantai south line as the raw material,the ammonia alkali waste liquid and fresh water were mixed and then the solution extraction reaction was used to remove sulfate radical and produce liquid salt for soda ash.Pilot scale research was used to optimize the process conditions.On the basis of the optimum process conditions of pilot test,the influence of polyacrylamide on the sedimentation effect of calcium sulfate dihydrate was determined.The results of pilot study showed that the volume ratio of ammonia alkali waste liquid to fresh water in the slag washing process was 1∶9,the residence time of slag washing was 2.5 h,the residence time of brine making was 3 h,the optimal n（sulfate）∶n（calcium ion） for the secondary desulfurization of the reaction tank was 1∶0.75,and the residence time of the secondary desulfurization of the reaction tank was 5 min.When the amount of polyacrylamide added in the secondary sedimentation process was 62.5 mg/L,the sedimentation effect of calcium sulfate dihydrate was better,and the light transmittance of liquid salt was≥80%.Under the optimized process conditions,the liquid salt standard for enterprise soda production could be reached,in which the mass concentration of calcium ion was ≤2 g/L,the mass concentration of sulfate radical was≤5 g/L,and the mass concentration of sodium chloride was≥305 g/L.at the same time,the comprehensive utilization of resources could be realized by using this process.