New Developments in Pyrometallurgy
Research and development in pyrometallurgy continue to attract attention from the scientific and engineering community as a result of the irreplaceable role of pyrometallurgy in the extraction and processing of metals for society. Development of energy-efficient and environmentally friendly pyrometallurgical processes continues to be pursued in the advancement of metallurgical technology and to contribute to continuous innovations in the field. In this section of the journal, ten articles are presented to address many new and diverse fields in pyrometallurgy. In the first article titled ‘‘Highlights of the Salt Extraction Process,’’ Aida Abbasalizadeh et al. discuss the characteristics, achievements, and future potential of a new process using molten (chloride) salts for the recovery of metals from several primary and secondary resources. The process has been identified for application in a broad range of areas, such as the treatment of metallurgical slags, recovery of lead from cathode ray tube glass, and recovery of rare earth metals from magnet scrap. It is considered a promising process for the recovery of strategic metals with the apparent advantage of being environmentally friendly. This could be one technology to watch. In the next article, Mohassab Yousef MohassabAhmed and Hong Yong Sohn report on the effect of water vapor on slag chemistry associated with a novel flash ironmaking technology in their article titled ‘‘Application of Spectroscopic Analysis Techniques to the Determination of Slag Structures and Properties: Effect of Water Vapor on Slag Chemistry Relevant to a Novel Flash Ironmaking Technology.’’ The University of Utah has been studying this process for many years, and this article serves as an update on aspects of this important work. The CaOMgO-SiO2-Al2O3-FeO-MnO-P2O5 slag system with the CaO/SiO2 ratio ranging from 0.8 to 1.4 was selected for the new flash process operating temperatures between 1550 C and 1650 C. It shows that water vapor significantly affects the chemistry of the slag and strongly affects the phase equilibria in the slag as well as the equilibrium distribution of elements (e.g., S, P, and Mn) between slag and molten metal. These results may provide a useful guide for controlling the quality of the produced iron, the iron loss into the slag, and the lining erosion. The next article titled ‘‘Thermodynamic Analysis of Looping Sulfide Oxidation Production of MoO2 from Molybdenite for Energy Capture and Generation’’ by Joseph D. Lessard et al. reports on the new looping sulfide oxidation process. Building on an earlier JOM article, it describes the selective and efficient production of MoO2 from MoS2 concentrates through the conversion of MoS2 to MoO2 with O2 and MoO3. The fourth article is concerned with new developments in nickel laterite technology. In this article titled ‘‘Carbothermic Reduction of Nickeliferous Laterite Ores for Nickel Pig Iron Production in China: A Review,’’ Mingjun Rao et al. review new developments in laterite metallurgy, in particular, in the so-called Krupp Renn process for producing a type of nickel pig iron from several nickel laterite ores. It shows that the relatively low temperature (below approximately 1300 C) solid-state reduction of nickeliferous laterite ores followed by magnetic separation offers an interesting route for producing a ferronickel at potentially lower cost by eliminating high-temperature electric furnace smelting. Conventional technologies are also reviewed. The article includes several interesting graphs presenting statistical data on the nickel market. The measurement and control of pyrometallurgical processes are vitally important issues. Jan Matousek, in the fifth article in this series titled ‘‘Oxidation Potentials in Iron and Steel Making,’’ Zhiwei Peng and Phillip J. Mackey are the guest editors for the Pyrometallurgy Committee of the TMS Extraction & Processing Division, and coordinators of the topic ‘‘New Developments in Pyrometallurgy’’ in this issue. JOM, Vol. 65, No. 11, 2013