Study of production of copper from malachite ore by application on hydrometallurgical methods

In this study, the production of copper was examined by applying hydrometallurgical methods to malachite mineral which is one of the oxidizied copper ores. The first step of the hydrometallurgical methods is leaching. The leaching and kinetics of malachite (CuCO3.Cu(OH)2) ore were investigated using perchloric acid solutions. In the runs, the perchloric acid concentration (C), the particle size (PB), the solid to liquid ratio (K/S), the stirring speed (KH) and the reaction temperature (T), have been chosen as variable parameters. Perchloric acid concentration, solid size, stirring speed, solid/liquid ratio and temperature were chosen as variable parameters on leaching process. It was determined that the leaching rate increased with increasing perchloric acid concentration, temperature and agitation speed, as well as decreasing particle size and solid-to-liquid ratio. It was observed that the dissolution of iron in the ore was substantially affected from acid concentration. By controlling of the reaction conditions, it was found that the amount of copper passing to the solution medium can be high and the amount of iron can kept at low levels. It was found that the leaching reaction followed the mixed kinetic control model. The activation energy of this leaching process was calculated to be 34.69 kJ/mol. As a result, the kinetic expression including the reaction parameters used in this leaching process can be written as follows: [1-(1-X_Cu )^(2/3) ]^2= 0.00014.(C)^0.643.(PB)^(-1.554).(K⁄S)^(-0.842).(KH)^2.155.exp⁡((-4172)⁄T)t Second process step is the solvent extraction. The winning and kinetics of solvent extraction of copper from leach solution were examined by using Acorga M5640 extractant. Initial pH of aqueous solution, (C) concentration of Cu(II), temperature (T), stirring speed (KH) and the organic phase ratio (RH) were chosen as variable parameters for solvent extraction experiments. It was determined that the solvent extraction rate increased with increasing stirring speed, organic phase ratio and temperature. It has been observed that the pH 1 value is effective in selectively recovering copper. Kinetic model of the solvent extraction process were as follows. The activation energy of the extraction process was estimated to be 50.04 kJ/mol. for pH>1, -In(1-Y_Cu)=〖9.5.10〗^9 (RH)^1.069 〖(C)〗^(-13.949) 〖(pH)〗^0.518 〖(KH)〗^2.157 exp((-6018.8)⁄T)t for pH<1, -In(1-Y_Cu)=〖9.5.10〗^9 (RH)^1.069 〖(C)〗^(-13.949) 〖(pH)〗^1.295 〖(KH)〗^2.157 exp((-6018.8)⁄T) Maximum copper extraction yield was found to be 99%. The effects of parameters such as aqueous solution pH, temperature, the organic phase ratio organic phase/aqueous phase ratio of mass transfer of between immiscible stationary liquid phases were investigated. In stripping experiments, temperature, perchloric acid concentration, stirring speed and stirring time were choosen as variable parameters. It was determined that the stripping rate increased with increasing temperature, perchloric acid concentration, stirring speed. Stripping time may be sufficient in 10 minutes. The activation energy of stripping process was calculated 32.42 kJ/mol. The process is concluded that the controlled diffusion. Stripping the loaded copper phase kinetics with perchloric acid it was concluded to be represented by the following models. -In(〖1-Z〗_Cu)=166.77(〖(R_2 Cu)〗^(-0.6889) 〖(C)〗^0.929 〖(KH)〗^1.339 exp(-3899.2⁄(T)))t Temperature, applied voltage, distance between electrodes and stirring speed were chosen as variable parameters for electrolysis experiments. It was determined that the electrolysis rate increased with increasing stirring speed, temperature and applied voltage. the kinetic expression including the reaction parameters used in this electrolysis process can be written as follows: -In(1-X_e)=37.02.[(C)^0,8583.〖(V_e)〗^4.8078.(d_e )^n.(KH)^w.exp⁡(-2846⁄T]t where, n= 1.319 for distance between electrodes < 5 cm n= -2.319 for distance between electrodes >5 cm metalic copper deposition fraction about h= 1.295 for Xe < 0.6 h= 0.875 for Xe > 0.6 The activation energy of electrolysis process was calculated 28.46 kJ/mol and the process was determined to be diffusion controlled. The obtained data is low-grade copper oxide ore leaching, solvent extraction and electrolysis process with the production of copper have shown that it is possible.