Emerging technologies in extraction and processing of metals

Abstract

The growing need to conserve energy and materials and prevent environmental pollution led to an increased demand for better understanding of potential as well as existing processes. In this context, thermodynamic and transport modeling of materials and processes provides a rapid and cost-effective means of conducting and minimizing the complexity of experimental investigations and developing innovative and environmentally friendly metallurgical processes. This presentation concentrates on some fundamentals on new technologies as extractive metallurgy of copper, lead, aluminum, and other nonferrous metals and processing of nanocomposites. The newer routes of copper smelting and modeling of impurities in copper and lead slags and mattes are reviewed. The copper smelting capacity increased by a factor of 10 during the last three decades, the smelting rate increased by a factor of 6, and the process fuel equivalent decreased by a factor of 2. The a priori prediction, with no adjustable parameters, of impurity capacities of S and As in copper slags and S in lead slags, based on the Reddy-Blander model, is reviewed. Excellent agreement between the model-predicted capacities data and laboratory experimental and industrial data was observed. The model is an invaluable tool for optimization of process parameters in the efficient removal of impurities from the nonferrous-metals smelting and refining processes. A new in-situ processing technology for the production of a lightweight alloy matrix with ceramic particle reinforcements such as SiC in aluminum alloy matrix composites by bubbling reactive gas is reviewed. Thermal plasma processing of a nanoscale aluminum alloy matrix with TiC and TiN composites is discussed. The in-situ formed reinforcements are thermodynamically stable, and the composite particles are of uniform size. The optimum process parameters for the production of composite powders by thermal plasma are discussed. A low-temperature aluminum production and refining process using ionic liquids as electrolytes is reviewed. This newly developed aluminum production process has many advantages over the current industrial process, and the energy consumption is closer to the thermodynamic limit of aluminum production.