卤水复分解法制备纯碱——盐析结晶、产品质量、盐析剂循环

Double decomposition for producing soda ash from brine——salting-out crystal,quality of producting,salting-out agent circulation

介绍了一种采用添加盐析剂的方法从卤水、碳铵中制备纯碱的新工艺。采用BaCl2-Na2CO3-NaOH法净化卤水，使其中主要杂质Ca2^＋、Mg2^＋、SO4^2-降低到1×10^-4％，达到反应要求。卤水与碳酸氢铵复分解反应制取碳酸氢钠和氯化铵，碳酸氢钠结晶率一般为70%--79%，加入盐析剂可以使碳酸氢钠结晶率提高到90%以上。煅烧碳酸氢钠得纯碱，产品符合GB210．1—2004Ⅱ类一等品要求。加入的盐析剂无需蒸发，可循环使用，耗能低，工艺简单，流程短，无污染。

This article introduces a new technology for the preparation of soda ash with brine and ammonium bicarbonate with addition salting - out agent. Purification of brine using the method of Ba- C12 - Na2CO3 - NaOH is to reduce the significant impurities including Ca2^＋、Mg^2＋ 、SO4^2- to 1 × 10^-6 to meet the requirement of reaction.In the production of soda ash and ammonium chloride with brine and ammonium bicarbonate by double decomposition, the crystallization rate of sodium bicarbonate is generally 70% --79%. The crystallization rate of sodium bicarbonate could be increased to 90 % and above with addition of salting-out agent. Soda ash produced by calcining sodium bicarbonate complies with the quality requirements of GB210.1 - 2004 Ⅱ. Salting - out agent doesn＇ t need evaporation and can be used circularly. This process has many advantages, such as low energy consumption, simple and short process flow and pollution free.