Along with the increasing demand for the TiO2 pigment, the ilmenite smelting process has also become significant because it can utilize both rock- and sand-type ilmenite. However, due to the high liquidus temperature of the TiO2 slag system, the smelting process is highly energy consuming. In the present study, the viscosity of molten ilmenite slag was estimated using molecular dynamic simulations at a high temperature to achieve an appropriate and efficient slag design. To verify the validity of the simulation technique, experimental measurements were performed in parallel and their results were compared. The effects of FeO and Na2O addition on viscosity of TiO2 slag were also investigated. The addition of Na2O as a flux enhanced the ilmenite smelting process by not only lowering the liquidus temperature but also slowing the drastic viscosity increase. Statistical information obtained from the molecular dynamic simulations revealed a three-dimensional TiO6 octahedral network structure. The relationship between viscosity and structural change with varying FeO and Na2O concentrations was explored considering the coordination number of Ti and various bonding types.
14 January 2020 in ACS Sustainable Chemistry & Engineering
This study delves into the application of oxidative refining for the recovery and concentration of precious metals, namely palladium (Pd) and gold (Au), from waste electrical and electronic equipment by WEEE recycling, leveraging pyrometallurgical techniques. The primary objective is to optimize refining parameters, encompassing variations in gas pressure, temperature, and gas composition, to maximize the extraction and purification of precious metals from recycled materials. Through an array of comprehensive characterization techniques, encompassing microstructural analysis, elemental composition assessment, and metal concentration measurement, this study scrutinizes the potential of oxidative refining. The conclusive findings underscore the remarkable potential of oxidative refining in augmenting the efficiency and effectiveness of metal recovery from waste printed circuit boards (PCBs), with a pronounced emphasis on the concentration of Pd and Au. This research not only highlights the promise of oxidative refining but also concludes that optimizing process parameters, such as a N2/O2 mixed gas pressure of 4 L/min, a process time of 40 min, and a temperature of 1400 °C, is imperative for achieving the highest efficiency in metal recovery from electronic waste, especially precious metals like Pd and Au. It further contributes to the sustainable management of electronic waste and the strategic extraction of valuable precious metals.
1 August 2019 in Metallurgical and Materials Transactions B