Proceedings of the International Seminar on Mineral Processing Technology - 2006, Chennai, India. pp. 112 - 118. Characterization Studies on Lead-Zinc Tailings from Rampura—Agucha Mines K. Udaya Bhaskar, M. Ravi Raju, K. Kosala Rao, P. Banerjee, J.K. Srivastava' and J.P. Barnwal Regional Research laboratory, Hoshangabad Road, Bhopal — 462026 Corresponding author: Dr.K. Udaya Bhaskar Email: kubhaskar2001 @yahoo . com Chemical Engineering Department, Ujjain Engineering College, Ujjain - 456001 Abstract The process tailings of base metal industries contain considerable amounts of acid generating 'pyrite and sulfides of other minerals. The recovery of sulfide minerals from the tailings not only will have environmental advantage but will also result in conservation of mineral wealth. For any such recovery activity, it is essential to characterize the tailings for physical, chemical and mineralogical characteristics. In the present study, typical lead-zinc tailings sample from the operating plant at Rampura-Agucha mines of Hindustan Zinc Limited was collected and characterized for size distribution, size by size chemical composition and mineral phase analysis through X-ray diffraction method. The size-by-size metal contents indicated increasing levels of silver and pyrite with decreasing particle size and the lead and zinc bearing minerals are segregated at relatively coarser size fractions. Microscopic studies of the coarser fractions have indicated that the lead and zinc minerals are in unliberated form. The XRD study has indicated that quartz is the major mineral phase followed by pyrite, sphalerite, galena and silver. The overall tailings sample was found to contain 19.41% of pyrite, 2.02 % of zinc, 0.69 % lead, and 26.94 ppm of silver contents. INTRODUCTION Lead and zinc are important non-ferrous minerals. In India major lead-zinc deposits are located in Rajasthan state. Among the reserves in Rajasthan State, the deposit at Rampura-Agucha in Bhilwara district is a promising one.. The deposit has an ore reserve of 61.1 million tons, with an average grade of 1.50% of lead and 4.5% of zinc (Bull, 1981). In general lead-zinc ores are concentrated adopting grinding followed by sequential flotation technique in which lead minerals are floated in the first stage further followed by flotation of zinc minerals (Gokhale et.al., 1983). During flotation, pyrite is rejected into the tailings by adding suitable depressants like sodium sulfide and cyanides. In this process some portions of sulphide minerals of lead, zinc and precious metals like silver and cadmium are also lost into the tailings as metal losses. The sulphides of these minerals entering the tailings generate acids, which leach away the heavy metals and further contaminate ground water. It is estimated that for every 141,374 tons of zinc and 45,655 tons of the lead metals recovery, the tailings generated would be around 6.935 million tons. Having realized the importance of mineral conservation and environmental point of view, a test work has been conducted to characterize the lead-zinc process plant tailings of Rampura-Agucha Mines to obtain information on mineralogy, size distribution and size-by-size metal composition. Characteristics like particle size distribution, size-by size metal composition and mineralogical data are a reliable guide that will give some idea on the performance of different mineral processing 112