International Process Metallurgy Symposium in Honour of Professor Pekka Taskinen - Metallurgy as a tool for challenges in circular economy

This International Process Metallurgy Symposium in Honour of Professor Pekka Taskinen was already the second honorary symposia in Aalto University School of Chemical Engineering, Department of Chemical and Metallurgical Engineering, so it was already a tradition. It truly was International Symposium having presenters from more than ten nationalities. The title of this Symposium includes a sub-title of “Metallurgy as a tool for challenges in circular economy”, which emphasizes the important role metallurgy and metallurgists have in solving the resource deficit in metals and minerals. We have already seen the shift from “traditional” raw material research towards recycled materials and their impact on metallurgical processes. Another emerging or growing trend is the need and request for zero waste processes. All this underlines the importance of fundamental metallurgical research, knowledge and education

Pulsed laser deposition of CdWO4CdWO_4 thin films

Thin $CdWO_4$ films were produced on various substrates by pulsed laser deposition. A method of producing transparent films of high structural and optical quality on MgO substrate was developed. It is based on deposition of an amorphous film from a non-stoichiometric $CdWO_4$–CdO target and a consequent crystallization of the film in oxygen atmosphere at 750 °C. The quality of the films produced was verified by x-ray diffraction, electron probe microanalysis, scanning electron microscopy, Raman and optical spectroscopy

Equilibrium of Copper Matte and Silica-Saturated Iron Silicate Slags at 1300 °C and PSO2 of 0.5 atm

Experimental study on the phase equilibria between copper matte with silica-saturated iron silicate slags was conducted at 1300 °C and PSO2 = 0.5 atm. The high-temperature isothermal equilibration in silica crucibles under controlled flowing CO-CO2-SO2-Ar was followed by quenching in an ice–water mixture and direct phase composition analyses by an electron probe X-ray microanalyzer. The equilibrium compositions for matte and slag, as well as the distribution coefficients, were displayed as a function of matte grade. The data set obtained at PSO2 = 0.5 atm and the previous study at PSO2 = 0.1 atm by the authors enabled an investigation on the impacts of PSO2 as well as Al2O3 and CaO additions on phase equilibria in the multiphase copper matte smelting system. Thermodynamic calculations using MTDATA software were performed to compare the experimental results with modeling. The present results enrich the fundamental thermodynamic information for the matte/slag/tridymite/gas equilibria in the primary copper smelting process at high PSO2.Peer reviewe

Recovery of Precious Metals (Au, Ag, Pt, and Pd) from Urban Mining Through Copper Smelting

With the aim of investigating deportments of precious metals in pyrometallurgical processing of waste electrical and electronic equipment, the distributions of selected precious metals (gold, silver, platinum, and palladium) between copper matte and three different silica-saturated slags (pure FeOx-SiO2, FeOx-SiO2-Al2O3, and FeOx-SiO2-Al2O3-CaO slag) were investigated at 1300 °C in controlled flowing CO-CO2-SO2-Ar gas atmosphere by a high-temperature isothermal equilibration technique. The phase compositions were analyzed by Electron Probe X-ray Microanalysis and Laser Ablation-High Resolution Inductively Coupled Plasma-Mass Spectrometry. It was shown that the distribution coefficients of gold, platinum, and palladium between matte and slag (Lm/s(Me) = [Me]in matte/(Me)in slag) were very high and increased with increasing matte grade. The distributions to the matte phase were increased by adding basic oxides alumina and lime into the acidic silicate slags. The experimentally measured distribution coefficientsLm/s(Me) followed the order of platinum > palladium > gold > silver. The present experimental results can be used for upgrading thermodynamic databases for the complex recycling processes through nonferrous smelting.Peer reviewe