Abstract: There exist hundreds of soda lakes in Inner Mongolia Autonomous Region and other provinces of China, with their main constituents Na2CO3, NaHCO3, NaCl and Na2SO4. If the brine is processed by simple carbonization to precipitate NaHCO3 as an intermediate product and the mother liquor is discarded, the utilization of sodium will be rather low. An ammoniation-carbonation process was proposed[5], in which a large proportion of NaCl and Na2SO4 will be converted to NaHCO3 also. In addition, NH4Cl and the unreacted Na2SO4 may be separated as final products from the NaHCO3 mother liquor. For the purpose of optimizing operation, the phase diagram of Na+, NH4+//HCO3-, Cl-, SO42-, H2O system at 35℃ was studied and some operating problems were discussed. The phase diagram showed that in order to raise the NaHCO3 yield, the[2NH3]/([Cl22-]+[SO42-])ratio in the ammoniated brine must be increased. Take the Dabusu Soda Lake brine as example, if the[2NH3]/([Cl22-] +[SO42-]) ratio is raised to 0.738, the sodium utilization UNa would be increased to 78.9%. But this is the limit value for [2NH3]/([Cl22-]+[SO42-]) ratio. If it is exceeded, NH4HCO3 would be precipitated together with NaHCO3.

摘要： 将盐碱湖的卤水氨化,然后碳酸化,可以大大提高钠利用率.为了研究其最适条件,特研究了Na~+、NH_4~+/HCO_3~-、Cl~-、SO_4~(2-)、H_2O体系相图,并以此对如何提高钠利用率进行了讨论.