New Directions in Mineral Processing, Extractive Metallurgy, Recycling and Waste Minimization: An EPD Symposium in Honor of Patrick R. Taylor: Mineral Processing
Sponsored by: Society for Mining Metallurgy and Exploration, TMS Extraction and Processing Division, TMS: Pyrometallurgy Committee, TMS: Hydrometallurgy and Electrometallurgy Committee, TMS: Materials Characterization Committee, TMS: Energy Committee, TMS: Recycling and Environmental Technologies Committee
Program Organizers: Ramana Reddy, University of Alabama; Corby Anderson, Colorado School of Mines; Erik Spiller, Colorado School of Mines; Edgar Vidal, NobelClad; Camille Fleuriault, Eramet Norway; Alexandra Anderson, Gopher Resource; Mingming Zhang, Baowu Ouyeel Co. Ltd; Christina Meskers, SINTEF
Thursday 8:30 AM
March 23, 2023
Room: 33C
Location: SDCC
Session Chair: Edgar Vidal, NobelClad; Tao Wang, Rio Tinto
8:30 AM Invited
Titanomagnetites: Ores of the Future?: Thomas Battle1; 1Extractive Metallurgy Consultant
There is a solid-solution series between magnetite (Fe3O4) and the iron-titanium mineral ulvospinel (Fe2TiO4). There is a large volume of this mineral series in many locations in the world. At one extreme, this is a valuable iron ore; at the other, a titanium ore. But in between? Pat Taylor and his research group have worked in the processing of titanomagnetites and a major accessory mineral to these systems, ilmenite (FeTiO3). The development of technologies for processing of these ores - for minor contained elements such as vanadium and chromium, as well as iron and titanium - will be discussed, as well as future prospects.
9:00 AM
NbC-containing High Carbon Steel Grinding Media Development: Casey Brown1; John Heerema2; Charles Enloe3; Erik Spiller4; John Speer1; Emmanuel De Moor1; 1Colorado School of Mines, Advanced Steel Processing and Products Research Center; 2Gerdau Long Steel; 3CBMM; 4Colorado School of Mines
The purpose of this work was to assess the effect of niobium alloying and NbC eutectic carbides in the microstructure on the performance of steel grinding media. Grinding is essential in the mining industry to promote mineral liberation in extracted ore and accounts for approximately 40% of all mining energy costs. Laboratory-prepared heats were produced via vacuum induction melting of industrial bar stock with a composition of Fe-1.0C-0.96Mn-0.22Si-0.26Cu-0.11Ni-0.50Cr-0.005V-0.012Nb and incremental alloying of Nb with concentrations of 0.01, 0.25, 0.5, and 1.0 wt %. NbC has been reported to reach hardness values up to 3000 HV. SEM examination revealed eutectic NbC networks that were broken up and distributed within the microstructure during hot rolling. Dry sand/rubber wheel (DSRW) testing was performed to evaluate wear resistance as a function of Nb alloying. Results showed a 65% decrease in mass loss between the 0.01 and 1.0 wt pct Nb alloys.
9:20 AM
Evaluating Waste Reprocessing: Framework Development: Joseph Trouba1; Nina Zaronikola1; Roderick Eggert1; Elizabeth Holley1; 1Colorado School of Mines
Mining wastes are increasingly proposed as sources for critical minerals, with reprocessing incentivized by both waste minimization and critical element recovery. One problem often encountered results from employing elemental assays as evidence for potential recovery without explanation of why the valuable components went unrecovered to begin with. Slags, tailings, and other mining wastes form during processes designed to maximize profit. For reprocessing to be economically possible, something must have changed from when they were generated.The objective of this work is to provide a framework, based on industrial examples, for evaluating waste reprocessing projects by identifying the key variables that must change to positively impact project viability. Factors discussed include technological developments, constituent economic value, awareness of secondary resources, ESG influences, and government policy. Critical element recovery is the focus of this work, but the conclusions can be applied much more broadly.
9:40 AM
Investigation of Heavy Metal Levels in Tin Mine Wastes and the Implication to Mine Closure Plan: A Case Study of Rutongo Mine, Rwanda: Jean Ishimwe1; Abubakary Salama1; Kenneth Sichone2; Kenneth Sichone3; 1University of Dar es Salaam; 2Harvest University; 3University of Rwanda
Rwanda has not experienced any mine closure since mining operations started in the 1930s. To date, there is no information on good practice mine closure procedures despite the presence of old mining operations. Therefore, this study is the first of its kind to scrutinise the closure plan for Rutongo, a tin mine that has existed for over 80 years and is approaching its mine life. The study seeks to quantify heavy metal levels in mine wastes and suggest a closure plan for waste rock dumps (WRDs) and tailings storage facility (TSF) so as to reduce contamination effects during and after cessation of operations. Geochemical characterization using X-Ray Fluorescence (XRF) and Inductive-Coupled Plasma Mass Spectroscopy (ICPMS) was conducted. Results indicated the presence of pyrite and arsenopyrite, the deleterious elemental concentration ranging from 120 mg/kg to 710 mg/kg As, 10.32 mg/kg to 22.35 mg/kg Co and 8.6 mg/kg to 128 mg/kg Cr. When these results are benchmarked against various soil quality standards, it is evident that the mine wastes are contaminated by As and a critical concentration of Cr and Co. A mine closure plan with remediation and containment strategies for bio-accumulation of As, Cr and Co and use of covers that have a capillary barrier to minimise water percolation, and a top soil that supports vegetation backed by hyper-accumulators was recommended.
10:00 AM Break
10:20 AM Cancelled
Processing of Luanshya Copper Smelting Slag: Yaki Namiluko1; Yotamu Hara1; Rainford Hara1; Nachikonde Fumpa1; Agabu Shane1; Makwenda Ngomba1; Ireen Musukwa1; Ronald Hara1; 1Copperbelt University
Copper smelting slag from Luanshya of the Copperbelt province of Zambia with about 2 weight% copper, 0.2 weight % cobalt, 0.8 weight % chromium, 6 weight% sulphur and 18 weight% iron, the remainder being silica, aluminium, calcium and magnesium oxides, was processed. Sulphur is mostly present in elemental form. The presence of sulphur and chromium makes this slag an environmental hazard. Mineralogical examination showed that chromium and cobalt are predominantly present in chromite and complex fayalite phases, respectively. However, copper is mainly present in the sulphide or matte form. Copper was upgraded to more than 25 weight % via a combination of screening, magnetic separation and froth flotation. Sulphur was recovered as a concentrate at a grade of 73 weight % via pre-flotation. Reductive roasting followed by magnetic separation or acidic leaching were carried out. Chromium was upgraded by a factor of 8 in the weakly magnetic fraction. Recovery of 55 – 70 % for cobalt was obtained after acidic leaching of reductively roasted samples.
10:40 AM
Separation of Li and Co from LiCoO2 Cathode Material through Aluminothermic Reduction Using Different Aluminum Sources: Chemical Grade, Swarf, and Dross: Deddy Nababan1; Reiza Mukhlis1; Yvonne Durandet1; Leon Prentice2; M. Akbar Rhamdhani1; 1Swinburne University of Technology; 2CSIRO Manufacturing
The worldwide ever-increasing vehicle uptake escalates the number of end-of-life lithium-ion batteries that need to be managed. Aluminothermic reduction is considered as an alternative approach for separating Li and Co from LiCoO2, the most common material used as batteries’ cathode. The current study evaluates the potential use of three different aluminium sources (chemical grade, waste swarf, and waste dross) as reductants for the aluminothermic reduction process. Systematic thermodynamic analyses have been carried out using the FactSage thermochemical package to identify the optimum conditions and the reaction products at various temperatures. Selected experiments were carried out to demonstrate the process. In the case of reduction with chemical grade aluminium, Co could be extracted as Co metal or Co-Al alloy; while Li is distributed to Li (g) and slag. The impurities in the waste swarf and Al dross were found to affect the Co and Li products and their separation mechanism.
11:00 AM
Towards Framework Development for Benchmarking Energy Efficiency in Foundation Industries: A Case Study of Granulation Process: Shoaib Sarfraz1; Ziyad Sherif1; Mark Jolly1; Konstantinos Salonitis1; 1Cranfield University
The foundation industries include glass, metal, ceramics, cement, paper and chemical sectors that support the demands of our modern lives. On the other hand, these industries are energy intensive. Energy requirements in foundation industries can be reduced by analysing and comparing the actual energy consumption of individual processes with their theoretical minimum value. In this study, a model has been proposed that can be used to calculate the theoretical minimum energy consumption of one such individual process i.e., granulation - A common process among the foundation industries which accounts for an average of 10-15% of the total energy consumption. A framework has also been developed that can be used by foundation industries to benchmark their energy efficiency and that provides an insight into the practical and theoretical potential for reducing their energy requirements.