铬盐清洁生产工艺中铝硅的脱除

Separation of aluminum and silicon in clean production process for potassium dichromate

研究铬盐清洁生产工艺中铝硅的脱除。理论计算表明:CaO加入浸出液中不会有致癌物铬酸钙的生成。结果表明:在反应温度为70-90℃时,添加适量的CaO,浸出液中的铝硅可以脱除到要求值。无铁渣存在时脱铝硅产物为Ca2.93Al1.97Si0.64O2.56(OH)9.44,有铁渣存在时为Ca3AlFe(SiO4)(OH)8。铁渣的存在可以加速铝硅脱除反应的速度,提高铝硅的脱除率,而溶液中K2CO3的浓度对CaO脱除铝硅的影响不大。

The separation of Al and Si in the clean production process for potassium dichromate was studied. The thermodynamic calculation results indicate that there is no produce of poisonous CaCrO4 when CaO is added into solution. When the amount of CaO addition adequately and reaction temperature between 70℃ and 90℃, the concentrations of Al and Si in solution can decrease to required value. The main product is Ca2.93Al1.97Sio.6402.56（OH）9.44 when reaction without iron residue, while it is Ca3AlFe（SiO4）（OH）8 when reaction with iron residue. The exist of iron residue can accelerate the rate of separate reaction, and improve the separation amount of Al and Si from solution. The concentration of K2CO3 in solution has no obvious effect on the separate reaction.