芒硝和碳酸氢铵复分解法制取纯碱工艺研究

Technology of soda ash by double decomposition method with mirabilite and ammonium bicarbonate

介绍了以芒硝和固体碳酸氢铵为原料，采用复分解法制取纯碱的工艺。芒硝和碳酸氢铵在适宜的条件下反应得重碱和母液。重碱经煅烧得纯碱，母液经蒸发得硫酸铵。产品均符合国标要求。探讨了影响纯碱质量的因素，确定了适宜的工艺条件：物料配比（硫酸钠与碳酸氢铵质量比）为1：1．2；反应温度35—40℃；反应时间1h；煅烧温度220～240℃；煅烧时间80min；蒸发温度80℃。此工艺用芒硝代替氯化钠为原料，使原料利用率高，生产成本低，工艺简单，投资少，利润高，无三废排放。

Introduced the method of preparing soda ash by double decomposition method with mirabilite and ammonium bicarbonate （ solid）. Mirabilite reacted with ammonium bicarbonate under the proper conditions to obtain sodium bicarbonate and mother liquor. Soda ash was obtained by calcining sodium bicarbonate. Ammonium sulphate was obtained by evaporating mother liquor. The product met the relative national standard. The factors influencing the quality of soda ash were obtained, and the feasible process conditions were confirmed：material mass ratio [ m（Na2SO4 ） ： m（NH4HCO3 ） ] was 1： 1.2; reaction temperature was 35 - 40 ℃ ; reaction time was 1 h ; calcining temperature was 220 - 240 ℃ ; calcining time was 80 min, and evaporating temperature was 80 ℃. The mirabilite replaced the salt as the raw material in the technology, which made raw material utilization ratio high and production cost low. The technology is simple with less investment, higher profits, and no discharge of the three -wastes.