First,brine is reacted with ammonium hydrocarbonate to obtain the sodium hydrocarbonate and the ammonium chloride solution,and then filtrated.

• 卤水制备纯碱分两步进行,第一步用卤水、碳酸氢铵反应得到碳酸氢钠微溶析出和氯化铵溶液,过滤。