利用氨碱生产废液进行浓海水净化软化工艺的研究

摘要

淡化后副产的浓海水应用于氨碱法纯碱生产中替代传统的淡水化盐,可以有效利用浓海水中资源,降低生产成本,但由于其中含有浓度较高的易结垢离子(Ca2+、Mg2+、SO42-),需要进行净化软化预处理.文章针对现有的浓海水净化软化过程中,处理工艺复杂、成本较高等问题,探讨了利用氨碱生产中副产的废液进行浓海水精制的工艺,并优化了关键工艺参数和技术条件,使处理后的水质符合制碱生产的要求.最佳处理条件为:Ca(OH)2与Mg2+摩尔比0.9～1.0,pH值≥10.61,蒸氨废液添加比例40％ (v/v),结晶促进剂添加量10％ (w/v),Ca2与Co32-摩尔比1.0～1.1.%The concentrated seawater can be utilized as alternative water resource in soda industry either to lower the water consumption or to reduce the raw material cost by recovering NaCl from waste liquid.However,the pretreatment of removing scale ion (Ca2+,Mg2+,SO42-) before the concentrated seawater use is relatively complicated and high cost.Hence,the study has developed a process for concentrated seawater refining by the waste liquid from the soda production and investigated its optimum condition:Ca (OH)2/Mg2+ =0.9 ～ 1.0,pH ≥ 10.61,proportion of deammoniation waste liquid adding to 40％ v/v,10％ w/v crystallization promoter input,and Ca2+/CO32-=1.0 ～ 1.1.