铟置换含铝废液制备聚合氯化铝的工艺和应用研究

以铟生产厂含Al2O3为3.69%的AlCl3废液为原料,采用直接中和法制备含钠的聚合氯化铝(PAC)溶液,研究了制备PAC的优化工艺条件、各因素对PAC性能和在处理蔗渣造纸中段废水时混凝效果的影响规律.结果表明,pH和熟化时间足主要影响因素,制备PAC时优化的工艺条件为:pH为3.0,反应温度为70℃,搅拌反应时间为...

Technology and Application Research of Polyaluminium Chloride Prepared from Aluminium-containing Waste Liquid in Indium Cementation

The sodium-bearing polyaluminium chloride(PAC) was prepared by direct neutralization method using the AlCl3 waste solution containing 3.69 % of Al2O3 provided by an indium producation enterprise.The optimum technological conditions in the preparation of PAC and the influence rules of each factor on the PAC performance and coagulation effect in the treatment of bagasse papermaking middle-stage wastewater were investigated.The results showed that pH value and aging time are the key factors.The optimum technological conditions for preparing PAC were: pH value 3.0,reaction temperature 70 ℃,reaction time 60 min,aging time 5 d.Under these conditions,the basicity,Al2O3 content were 50.8 % and 3.31 %,respectively.In the treatment of bagasse papermaking middle-stage wastewater,the removal rates of turbidity,chroma,and COD reach 94.2 %,93.8 %,and 45.5 %,respectively under the conditions of PAC dosage 350 mg/L and pH 6～7.Although the Al2O3 content of PAC was lower than the national standard,it also has good coagulation effect in the treatment of bagasse papermaking middle-stage wastewater.