Papers by Labone Godirilwe
The minerals, metals & materials series, 2024
International Journal of the Society of Materials Engineering for Resources
A pre-treatment method for upgrading gold from a polymetallic gold-zinc-lead ore by flotation was... more A pre-treatment method for upgrading gold from a polymetallic gold-zinc-lead ore by flotation was studied. X-ray diff raction analysis of the gold sulfi de ore showed that quartz, calcite, pyrite, sphalerite, and galena are the main constituents of the ore. The composition of the polymetallic ore contained 6.49 ppm Au, 3.48% Zn, 1.25% Pb, 17.98% Fe, and 20.36% S. Due to the complexity of the polymetallic ore, the gold recovery is generally low. The objective of this study is to develop a primary fl otation process to recover gold in a bulk sulfi de concentrate. The eff ects of particle size, collector type, fl otation time, and the slurry pH on the recoveries and grades of gold, zinc, and lead were investigated. The developed fl otation process consisted of rougher, scavenger, and cleaner stages. High recovery of gold was found to be linked with a high recovery of Pb which was achieved by the utilization of a mixture of collector AERO 7249 and PAX. The gold fl otation kinetics were fast with more than 50% of gold recovered within 5 minutes of fl otation. Under optimized fl otation conditions with rougher, scavenger, and cleaner stages, a total gold recovery of 88.36 % and a fi nal gold grade of 60.97 ppm were obtained. A total gold enrichment ratio of 9.4 was achieved, confi rming the viability of the fl otation method in upgrading the gold from the polymetallic sulfi de ore prior to further processing.
In pursuit of carbon neutrality, the demand for metals that are necessary for the development of ... more In pursuit of carbon neutrality, the demand for metals that are necessary for the development of clean energy technologies is rapidly increasing. Metallurgical waste, such as slag, presents a promising secondary source of these key metals. This research aims to develop an eco-friendly hydrometallurgical process to recover Cu, Ni, and Co from discarded copper/nickel slag. The high-pressure acid leaching (HPAL) was used to selectively leach Ni, Cu, and Co from the fayalite slag, yielding high leaching efficiencies of 99.9%, 89.4%, and 99.9%, respectively, with low Fe and Si tenors to the pregnant leach solution (PLS). The solvent extraction (SX) technique utilizing LIX 984N was used to selectively extract and enrich copper from the dilute PLS to about 23 g/L Cu with a very low Fe concentration of 0.05 g/L. Potassium amyl xanthate (PAX) solution was used to form Ni and Co xanthate complexes from the raffinate solution. Nickel was selectively recovered using ammonia solution, while coba...
International Journal of the Society of Materials Engineering for Resources
Passivation behavior of high silver containing copper anodes was investigated using slowly cooled... more Passivation behavior of high silver containing copper anodes was investigated using slowly cooled Cu-1%Ag anodes of diff erent lead (Pb) concentrations. The addition of Pb distributes silver in the Pb phase and reduces the amount of silver that is solidly soluble in copper and, thus, generates a fi ne silver powder on the anode surface which is a main contributing factor of passivation. Electrorefi ning experiments were conducted using a synthetic electrolyte containing 40 g/L Cu 2+ and 180 g/L H 2 SO 4 , at 60°C. SEM-EDS analysis was used to study the resulting anode slime and showed that increasing Pb content altered the anode slime structure from fi ne and compact to porous and less adherent to the anode surface. Utilizing a Cu-1%Ag-0.2%Pb anode yielded the longest passivation time with a low and stable cell voltage of 0.1V. The slime morphology was characterized by precipitated metallic silver particles either as inclusion or loosely present on the surface of the abundant complex Cu-Ag-Pb sulfate type of compounds. Because of the economic importance of silver recovery from the anode slime, understanding its behavior during electrorefi ning will enable operating with high impurity anodes especially in secondary copper processing where metallic impurities can result from e-waste and copper alloy scrap.
Metals, 2021
The flotation tailings obtained from Bor Copper Mine contain pyrite (FeS2) and chalcopyrite (CuFe... more The flotation tailings obtained from Bor Copper Mine contain pyrite (FeS2) and chalcopyrite (CuFeS2), these sulfide minerals are known to promote acid mine drainage (AMD) which poses a serious threat to the environment and human health. This study focuses on the treatment of mine tailings to convert the AMD supporting minerals to more stable forms, while simultaneously valorizing the mine tailings. A combination of hydrometallurgical processes of high-pressure oxidative leaching (HPOL), solvent extraction (SX), and electrowinning (EW) were utilized to recover copper from mine tailings which contain about 0.3% Cu content. The HPOL process yielded a high copper leaching rate of 94.4% when water was used as a leaching medium. The copper leaching kinetics were promoted by the generation of sulfuric acid due to pyrite oxidation. It was also confirmed that a low iron concentration (1.4 g/L) and a high copper concentration (44.8 g/L) obtained in the stripped solution resulted in an improve...
Minerals Engineering, 2021
Abstract The increase of impurities and complexity of copper ores are among the recent challenges... more Abstract The increase of impurities and complexity of copper ores are among the recent challenges in the mining industry. Complex carbonaceous sulfide ores are extremely difficult to treat due to their mineralogical complexity and impurities of organic carbon and carbonates. This study focuses on the development of a hydrometallurgical process for efficient copper extraction from complex carbonaceous sulfide ore which contains chalcopyrite, carbonates (dolomite and calcite), and carbonaceous gangue minerals. Characterization of the ore sample and leach residues was conducted using XRD and EPMA analysis, while ICP-OES was used for the determination of total dissolved metals in solution. High-pressure leaching of complex carbonaceous sulfide ore in oxygenated sulfuric acid solution was performed and the influence of leaching parameters such as sulfuric acid concentration, temperature, total pressure, and pulp density was studied. The extraction of copper increased with increasing temperature, sulfuric acid concentration, and total pressure. On the other hand, an increase in pulp density resulted in a decline in copper extraction due to an increased slurry viscosity and resistance in the diffusive mass transfer of reactants. Selective dissolution of copper from iron can be achieved by controlling free acidity in the pregnant leach solution (PLS). Under these leaching conditions: 100 g/L, 1 M H2SO4, 160 °C, 1.0 MPa total pressure, the highest copper and iron extractions achieved were 97.55% and 95.37%, respectively. Precipitation of copper from the PLS by NaSH sulfidization was investigated and more than 99.9% of copper was recovered at a Cu: NaSH molar ratio of 1:1.8.
Minerals Engineering, Nov 30, 2023
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Papers by Labone Godirilwe