Metal Recovery and Inorganic Eco-Materials from Tailings by Leaching-Sintering Processes

Abstract

Integrated tailings utilization of metallic ore is an overall situation associated with additional resourse storage, cleaning exploitation of mine, and environmental concerns. The purpose of the present work is to study and develop several corresponding recycling routes for tailings in accordance with chemical component and paragenesis state of minerals. Four typical gangues are collected from Chinese western dominant mine, discharged after mill run from rare earth metal ore, iron ore containing titanium and vanadium, nonferrous paragenetic ore (Pb, Zn, Sn, Sb, and other nonmetallic elements), and multimetal bonanza ore, respectively. To meet the demands for national recycling economics, it is necessary to design for recycled materials involving recovery of metal and preparation of advanced ecological ceramics through several novel approaches. Experimental results indicate that Ce, Y, and Nb rare metals have been leached from those tailings, and high performance Ca–Sialon can be synthesized from the as-discarded residues. A newly metal bonded ceramic eco-material, identified as Fe₃Si–TiCN–MgAl₂O₄ by XRD are discovered, whose fracture tougness is 12 MPa·m^1/2, which is successfully prepared by Carbonothermal Reduction Nitride route using iron–titanium tailing ore based on thermodynamics calculation. Zinc oxide and lead oxide powders can be extracted from nonferrous mineral tailings by hydrometallurgy process, regarded as fresh precursory powders for Pb(Zn_1/3Nb_2/3)O₃ functional ceramics, whereas magnetic Fe₃O₄ nanopowders are refined, originated from multimetal tailing ore by leaching-separating-precipitation. In addition, a practicing software, Search and Analysis System on Recycling of Solid Waste, has been developed to promulgate common knowledge to worldwide readers (Web site: http://recycling.net.cn).

Keywords:

• Ceramic
• Eco-material
• Ferrous
• Hydrometallurgy
• Leaching
• Metal
• Nanopowder
• Ore
• Rare earth
• Recovery
• Recycling
• Sintering
• Software
• Tailings
• Thermodynamic

ACKNOWLEDGMENTS

The research work is financially supported by Natural Science of Funding of China (Grant No. 50332010) and by National key technologies R&D of China (Grant No. 2006BAB12B03-05).