盐析效应对卤水制纯碱的影响

The Effect of Salt on Preparation of Soda Ash with Brine

卤水和固体碳酸氢铵复分解反应得碳酸氢钠沉淀和氯化铵溶液，碳酸氢钠经煅烧得纯碱。采用BaCl2-Na2CO3-NaOH法净化卤水，使其中主要杂质Ca^2＋、Mg^2＋、SO4^2-降低到20ppm，达到反应要求。研究了盐析效应对复分解反应的影响，盐析剂的加入使碳酸氢钠结晶率从70％～79％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。

Brine reacts with ammonium bicarbonate （solid） to obtain sodium bicarbonate and ammonium chloride liquor and then, soda ash can be obtained by calcining sodium bicarbonate. The brine was purified by method of BaCl2 -Na2CO3 -NaOH in order to make the main impurity including Ca^2＋ ,Mg^2＋ ,SO4^2- to be reduced to 20ppm for achieve the requirement of reaction. Study on the effect of salt on double decomposition reaction of brine and ammonium bicarbonate was investigated. The addition of salting-out agent improved the crystallization rate of sodium bicarbonate from 70% - 78% to above 90%. We got the soda ash by calcining sodium bicarbonate and the product met the quality requirements of GB210.1-2004 Ⅱ.