Mehmet Ali Topçu

Bio: Mehmet Ali Topçu is an academic researcher from Karamanoğlu Mehmetbey University. The author has contributed to research in topics: Copper & Leaching (metallurgy). The author has an hindex of 5, co-authored 13 publications receiving 57 citations.

Optimization of gold recovery from copper anode slime by acidic ionic liquid

Abstract: Hydrometallurgical gold recovery from primary or secondary sources is mainly based on a cyanide process, which is very dangerous for the environment due to the high toxicity levels. In view of the environmental effect, the present study proposes a new green solvent called 1-ethyl-3-methyl-imidazolium hydrogen sulfate (EmimHSO4) ionic liquid (IL) to recover gold from copper anode slime (CAS). The optimum leaching conditions for maximizing gold recovery were determined by orthogonal array (OA) of Taguchi’s experimental design method. OA L16 (44) including four parameters with four levels each, was used to examine the effects of IL concentration (20%, 40%, 60%, 80% v/v), temperature (25, 50, 75, 95 °C), time (½, 1, 2, 4 h) and solid/liquid ratio (1/10, 1/15, 1/20, 1/25 g/mL) on leaching efficiency of the gold recovery. Statistical analysis of variance (ANOVA) was used to determine the relevance between experimental conditions and gold recovery. The selective leaching tests results showed that gold recovery up to 89.07% was attained on laboratory scale under the optimum leach conditions: 80% IL concentration, 75 °C, 4 h and 1/25 g/mL solid/liquid ratio. According to these results, EmimHSO4 IL provides a very good ambiance for the oxidative leaching of gold and can be offered as an alternative leaching agent instead of harmful cyanide-based solvents.

Investigation of an alternative chemical agent to recover valuable metals from anode slime

Abstract: Anode slime (AS) including high content of precious metals is a by-product obtained after the electro-refining stage in copper production. In this study, it is aimed to recover Cu, Au, and Ag from the AS by using 1-butyl-3-methyl-imidazolium hydrogen sulphate ([Bmim]HSO4) ionic liquid (IL) as a green solvent. The effects of IL concentration, temperature, reaction time and pulp density on recovery of valuable metals were statistically investigated. A high copper recovery of 87.52% was obtained under optimum condition as in 60% (v/v) [Bmim]HSO4 at 50 °C after 2 h, pulp density at 40 g/L (1/25 solid/liquid ratio). Also, a remarkable gold recovery as 97.32% has been achieved in 80% (v/v) [Bmim]HSO4 at 95 °C after 4 h, pulp density at 40 g/L. Temperature and IL concentration were detected as the most effective parameters for copper and gold recovery from AS, respectively. Silver could not be recovered from the AS due to the lower solubility in [Bmim]HSO4 IL media. According to experimental results, [Bmim]HSO4 could be offered as an alternative leaching agent, instead of conventional solvents, to recover valuable metals from copper anode slime.

Investigation of zinc extraction from different leach residues by acid leaching

Abstract: With different properties, zinc is one of the most important non-ferrous metals and it is used in various application areas, especially as an anti-corrosion agent In Turkey, zinc production was based on zinc carbonate ores (ZnCO3), at Cinkur plant from establishment to 1997 due to high reserves of zinc carbonate After that, zinc concentrate coming from Iran was used in this plant over the last two decades Thus, two different leach residues called as Turkish leach residue (TLR) and Iranian leach residue (ILR) were accumulated more than one million ton in Cinkur stock piles In this study, it is aimed to investigate zinc recovery for each leach residue by use of sulphuric acid (H2SO4) and to compare the TLR and the ILR Initially, detailed chemical, mineralogical and thermal analyses of these different leach residues were carried out In order to investigate the effect of acid concentration and reaction duration on zinc recovery, leaching experiments were carried out at following conditions: 95 °C, 100 g/L pulp density and 600 rpm stirring rate According to the characterization results, the chemical compositions for both residues are nearly similar; however, experimental results show that zinc recovery per cent of the ILR was higher than that of TLR for all experimental durations and acid concentrations This may be due to the presence of Zn-containing compounds in the both residues at different percentages

Minimizing of copper losses to converter slag by a boron compound addition

Abstract: In copper production, the concentrate obtained after ore-flotation follows by pyrometallurgical route; Smelting, Converting and Fire Refining stages to obtain the anode plates. In this production process, a significant amount of copper (4–8 %Cu) goes to converter slag (CS) which is the most serious problem facing the copper sector. Therefore, in this study, it was aimed to minimize the copper losses to CS in converter stage by adding calcined colemanite (CC) which is a boron compound. After characterization of CS in detail, effect of the reaction temperature and CC addition were experimentally investigated. Then, thermochemical calculations of the slag with the addition of CC were carried out by using the Equilib and Phase Diagram modules of the FactSage thermochemical software. Experimental results show that the amount of copper losses to the CS can be decreased from 4.45% to 1.2% by adding 2% CC to the converter slag at the temperature of 1250 °C for 3 h reaction time.