利用铝土矿和铝酸钙制备聚合氯化铝的研究

Study on the preparation of PAC coagulant from bauxite and calcium aluminate

对利用铝土矿和铝酸钙采用二步法制备聚合氯化铝的工艺进行了研究.考察了制备聚合氯化铝的各种影响因素,确定了一段溶出的最佳条件:铝土矿焙烧温度650 ℃,焙烧时间1 h,酸浸温度85～95 ℃,盐酸质量分数20%,酸浸时间2 h;二段溶出过程中可以根据不同的盐基度要求控制铝酸钙的加入量.除浊实验结果表明,二步法制备的聚合氯化铝具有良好的混凝性能.

The preparation of PAC from bauxite and calcium aluminate by two - step method is studied and various effecting factors of preparation are also investigated. The optimum conditions for the first step are as follows ： the calcining temperature of bauxite 650 ℃, calcining time 1 h, the acid leaching temperature 85 -90 ℃, HCl concentration 20%, and leaching time 2 h. For the second step, the adding amount of calcium aluminate can be controlled according to the different basicity of PAC. The test results of turbidity removal show that the PAC prepared by two - step method has a good flocculation properties.