铬酸钠碳氨转化过程中铬的析出形式

Crystals in conversion process of sodium chromate with ammonia and carbon dioxide

根据测定的Na+,NH+4//CrO42-,HCO-3-H2O体系相图对铬酸钠碳氨转化过程中CrO42-析出形式进行分析,并结合实验研究提出相应的分离方法。结果表明铬酸钠碳氨转化过程中首先析出碳酸氢钠,铬会依次以铬酸铵钠和铬酸铵结晶形式析出,利用铬酸铵钠结晶与碳酸氢钠结晶的粒度和密度差别可用水力旋流器分离。

The crystals of chromates were determined in the conversion process of sodium chromate with ammonia and carbon dioxide according to the phase diagram of Na+,NH4+//CrO42-,HCO3--H2O system in this paper,the results show that NaHCO3,NaNH4CrO4·2H2O,(NH4)2CrO4 were produced in turn during the carbonization process,the granularity and density of three crystals were different obviously,three crystals could be separated with hydrocyclones.