Environmental assessment of filter cake wastes in zinc processing plants

In this paper, results of the study on heavy metals solubility behavior of Ni-Cd filter cakes in Iranian Zinc Mine Development Company (IZMDC) plants are investigated. The effects of pH, temperature, liquid/solid ratio and contact time on the release of heavy metals (Zn, Cd, Ni and Pb) into water media was examined. Also, “Extraction procedure tests” approved by EPA were applied to the residues. Moreover, statistical data analysis was performed and the most important parameters for dissolution of Zn, Cd, Ni and Pb were found to be the pH and L/S.. The concentration of Cd and Pb in the extracts obtained from filter cakes by applying EPA extraction procedures at pH ۵ are over ۱.۰ and ۵.۰ mg/L, which are toxicity limits, respectively. The concentrations of other metals in the solution are above the limits given by various quality standards for surface water.

کلیدواژه ها:

Zinc wastes ، Ni-Cd purification filter cakes ، EPA extraction tests ، Heavy metal pollution