镍冶炼废水处理方法

METHOD OF WASTEWATER TREATMENT FROM NICKEL METALLURGY

在镍冶炼过程中产生大量的废水，其中含有镍、铜、钴等金属离子．这种冶炼废水在排放前必须加以处理，以便回收有价金属元素和防止污染环境．作者采用中和－混凝法处理镍冶炼废水，并对方法进行了热力学分析，对混凝机理进行了研究．理论计算结果表明：Ni2＋，CU2＋，Co2＋开始沉淀的pH值分别为7．47，6．00和7．68；若沉淀到1mg／L以下时，所控制的pH值分别为8．48，7．01和8．70．通过实验获得的最佳条件为：pH＝9．0，聚合硫酸铁用量为镍含量的2倍，聚丙烯酰胺用量为4mg／L；处理后，废水中ρNi＜0．13mg／L，ρCo＜0．01mg／L，ρCu＜0．005mg／L．

A vast amount of wastewater is produced in nickel metallurgical process,which contains metal ions of Ni2+,Cu2+ and Co2+. This matellurgical wastewater must be treated before draining in order to recover the above valuable metals and prevent environmant pollution. In this paper wastewater from nickel metallurgy has been treated by using neutralization-flocculation. The principle of the method has been analyzed thermodynamically and the mechanism of flocculation has been discussed briefly. It is shown from the results of theoretical calculation that the initial pH of precipitation of Ni2+,Cu2+,Co2+ is 7.47, 6. 00 and 7. 68 respectively; if precipitated to less than 1 mg/L,the controlling pH is 8. 48,7. 01 and 8. 70 respectively. The optimal conditions obtained from tests are as fllows: pH 9. 0,amount of polyferric sulfate used 2 times of nickel content in the wastewater and polyacylamide 4 mg/L. After treatment the concentration of the species in wastewater,ρNi<0. 13 mg/L, ρCo<0. 01 mg/L, ρCu<0.005 mg/L.