Study On Comprehensive Utilization Of Zinc Kiln Slags

In this paper, the main methods recovering valuable elements from zinc-leaching residues are reviewed. The advantages and disadvantages of the methods are pointed out, a noval technology to recovery valuable elements from zinc-leaching residues is developed. Through a series of experiments to compare the advantages and disadvantages between process of reducing sulfuration smelting and process of molten chlorination, and select the reducing sulfuration smelting technology as the method to recover the valuable elements from kiln slag. In addition, to comprehensively utilize of kiln slag, we also study the occurrences of valuable elements in kiln slag by means of electron microscope, scan electron microscope and energy spectrum.The smelting method of reduction sulphidation smelting and metallic matte beneficiation for extracting Ga and Ge ferroalloy powder is developed for kiln slag with higher contents of Ga and Ge. Lab tests have been done with higher recoveries of Ga and Ge. Zn and Ag in the slag can be also recovered comprehensively. At the time of reduction sulphidation smelting, 86%~90% of Ga, 90% of Ge and 80~90% of Ag go into the matte while 94~95% of Zinc volatilizes. At the time of magnetic separation of metallic matte, 91% of Ga and 96.5% of Ge go into ferroalloy powder while over 85% of Ag, Cu and Pb enter into non-magnetic products. The beneficiation-metallurgy recoveries of Ga and Ge are 87% and 95% respectively. The Ga and Ge grades of the ferroalloy are 1900 g/t and 830 ~ 950 g/t , respectively. The concentration factors of Ga and Ge are 4.75 and 4.15~4.75, respectively. The related results will provide an effevtive guidance to recovery Ga and Ge from zine kiln slags.