TN689 : Optimizing the operational parameters affecting the copper oxide leaching of Fariman copper mine
Thesis > Central Library of Shahrood University > Mining, Petroleum & Geophysics Engineering > MSc > 2017
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Abstarct: In this research, copper oxide leaching of Fariman copper mine were investigated by various leaching agents including ammonium chloride, hydrochloric acid, nitric acid, citric acid and especially sulfuric acid. Leaching process kinetics and the influence of important operational parameters such as acid concentration, liquid to solid ratio, stirring speed, time and leaching temperature on the copper recovery were studied. Also, response surface methodology and central composite design were used to optimize the leaching process and to evaluate interactions between factors. The result showed that sulphuric acid was the most suitable leaching reagent. Copper leaching kinetics baxsed on shrinking core models indicated that the liquid film diffusion model (R2=0.969) and surface chemical reaction (R2=0.9752) have the highest correlation coefficients to experimental data. The activation energy was obtained 11.47, 26.69, 16.25 kJ/mol for liquid film diffusion, product laxyer and surface chemical reaction models, respectively, and it was determined that copper leaching rate follows from liquid film diffusion model. Evaluation of factors affecting the copper leaching indicated that the stirring speed, liquid to solid ratio and leaching temperature have the most influence on copper recovery by sulphuric acid solutions. Meanwhile, the modeling results baxsed on response surface model demonstrated that a quadratic model are fitted to experimental data and copper sulphuric acid leaching are strongly affected by interactions of temperature with acid concentration, stirring speed and liquid to solid ratio. Also, the findings showed that the leaching optimum conditions suggested using Design Expert software are achieved at parameters levels: sulphuric acid concentration of 12.92%, stirring speed of 600 rpm, liquid to solid ratio of 10 ml/g, solution temperature of 50 °C and leaching time of 79.98 min. Under these conditions the recovery of copper was 90.63%. Additionally, in order to confirm the validity of the model, three confirmation experiments were conducted at the predicted optimum conditions, which the average of copper recovery for three experiments was achieved 91.09%, and this indicates the suitability and accuracy of the model.
Keywords:
#Fariman copper oxide ore; Leaching; Kinetics; shrinking core model; activation energy; response surface method Link
Keeping place: Central Library of Shahrood University
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Keeping place: Central Library of Shahrood University
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