Mineral Processing
S. Feizollahi; A. Azizi
Abstract
The extraction behavior of Cu(II) ions from a real sulfate liquor obtained from the heap leaching stage of a copper oxide ore was investigated using a chelating reagent, Chemorex CP-150 in kerosene. A comparative study was also carried out on the extraction capability of Cu(II) ions using other solvents ...
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The extraction behavior of Cu(II) ions from a real sulfate liquor obtained from the heap leaching stage of a copper oxide ore was investigated using a chelating reagent, Chemorex CP-150 in kerosene. A comparative study was also carried out on the extraction capability of Cu(II) ions using other solvents including D2EHPA and Cyanex 272.Chemorex CP-150 demonstrated an effective and selective extraction performance of copper with the amount of extracted Fe less than 15%. Also the results obtained indicated that more than 66.4% and 96.99% of Cu were transferred to the organic phase in a single extraction stage using 15% (v/v) Chemorex CP-150 at the A:O phase ratios of 1:1 and 1:4, respectively. In addition, the McCabe-Thiele diagram exhibited that two extraction stages were required to achieve the maximum amount of Cu at a 1:1 phase ratio under the optimal conditions (25 °C, pH 2.5, and 20 min contact time). Also, thermodynamic data proved that the extraction process was slightly endothermic (ΔH = 7.62 kJ/mol), indicating the relatively smaller heat effects on the formation of a single complex species (CuR2). Stripping of copper from the loaded organic phase was also conducted, and it was found that ~99.38% copper could be recovered using 165 g/L H2SO4 at a 2:1 A:O phase ratio after 5 minutes stripping.
Seyed M. Seyed Ghasemi; A. Azizi
Abstract
The leaching kinetics of a low-grade zinc oxide ore in different acid media was investigated with respect to the experimental variables including acid concentration, temperature, liquid to solid (L/S) ratio, and stirring speed. The results obtained showed that the leaching reagent concentration and the ...
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The leaching kinetics of a low-grade zinc oxide ore in different acid media was investigated with respect to the experimental variables including acid concentration, temperature, liquid to solid (L/S) ratio, and stirring speed. The results obtained showed that the leaching reagent concentration and the reaction temperature exerted significant effects on the extraction of zinc, whereas the L/S ratio and stirring speed exhibited a relatively moderate effect on the leaching rate. The maximum leaching rate with inorganic acids was obtained to be 90.76%, while the maximum zinc recovery with citric acid was determined to be 88.68%. It was found that the zinc leaching process followed the kinetic law of the shrinking core model. It was distinguished that the dissolution rate was controlled by diffusion through the fluid film in the HNO3 medium with the activation energy of 4.38 kJ/mol, whereas when dissolution was performed in the presence of HCl, H2SO4, and citric acid, an intermediate process (i.e. a physico-chemical process) was the rate-controlling step.
