Bünyamin Dönmez

A kinetic study of the cementation of copper from sulphate solutions onto a rotating aluminum disc

Abstract The cementation kinetics of copper deposition from sulphate solutions onto aluminum was studied using a rotating disc electrode system. The effect of temperature, Cu++ ion concentration, rotational speed of the aluminum disc and pH was investigated. The activation energy was found to be 14.1 kJ mol−1, confirming that the rate of reaction was controlled by diffusion.

Calcination Kinetic of Magnesite from Thermogravimetric Data

The kinetic parameters of the thermal decomposition of magnesite were investigated using TGA data. For the kinetic analysis, the Coats–Redfern and Suzuki methods were separately applied. It was observed that the process fitted a first-order kinetic model and the values of the activation energies decreased with decreasing particle size, which can be attributed to the increasing particle internal resistance to the escape of CO 2 as the grain size increased. According to Coats–Redfern and Suzuki methods, the activation energy values, respectively, for the range of were found to be 236.25-278.37 and 255.52–302.21 kJ mol −1 respectively, for the range of particle size fraction used.

Optimisation of the chlorination of gold in decopperized anode slime in aqueous medium

Abstract A study is conducted to determine optimum conditions for the chlorination of gold in decopperized anode slime with chlorine gas in aqueous medium by the Taguchi experimental design method. The effect of parameters such as reaction temperature, reaction period, stirring speed and solid–liquid ratio was sought. The optimum conditions were found to be reaction temperature 60°C, reaction period 4500 s, stirring speed 600 min−1 and solid–liquid ratio 0.1 g ml−1. The experimental results showed that, under optimal leaching conditions, the extraction of gold could be over 99%.