KBİ cüruflarının H2O2 ortamında H2SO4 ile liç kinetiğinin incelenmesi

This study was conducted to investigate the extraction and leaching kinetics of metals as a result of applying leaching process to KBI (Samsun) Converter- flash slag mixtures in a hydrogen peroxide environment with sulphuric acid. As a result of chemical analyses of slag samples, Cu, Fe and Zn contents were determined as 3.00%, 31.72%, and 4.01%, respectively. In the studies conducted with solutions having different hydrogen peroxide and sulphuric acid concentrations in 1:10 solid/liquid ratio to determine a concentrated copper solution, it was determined that decomposition rate of hydrogen peroxide increased and the decomposition reaction was exothermic based on the increased acid and peroxide concentrations and because of the high amount of current solid matter in the medium, therefore, the isothermal conditions were deteriorated and the reaction did not proceed in a controlled manner. It was determined in the experiments in which hydrogen peroxide and sulphuric acid solutions were used alone as leaching reactant that satisfactory metal extractions could not be obtained and the amount of iron passing into the solution was very high especially in the experiments carried out in high acid concentration. Depending on the concentration of sulphuric acid, it was determined that the amount of iron passing into the solution increased up to 1.00 M H2SO4 concentration and approximately 40% of them passed into the solution. At the same conditions, it was determined that about 65% of zinc and 90% of copper were extracted. Although the copper and zinc extraction obtained under the experimental conditions with a high H2SO4 concentration was high, the amount of iron passing into the solution was also high in the same conditions, therefore it was understood that it should be studied at low acid concentration. It was found in the studies investigating the effect of temperature that extraction rate of the metals increased with increasing temperature. The results obtained from the experiments performed with mixtures containing 0.25 M H2SO4 and 2.00 M H2O2 depending on the time at the temperatures varying between 30–50C were applied to surface reaction controlled shrinking grain model and diffusion controlled shrinking core model, it was revealed as a result of the regression analyses that data showed a good agreement with the diffusion controlled model. Furthermore, activation energy of the copper leach by this method was calculated as 31.63 kJ/mol Cu with the help of Arrhenius equation. The experiments conducted to demonstrate the dependence of leaching kinetics on hydrogen peroxide concentration showed that leaching rate slightly increased with the increasing peroxide concentration and the level of leaching reaction was determined to be approximately 1 in concentration range of 0.5-3.0 M compared to peroxide. The experiments carried out to reveal the dependence of the copper extraction kinetics on the sulphuric acid concentration were examined in the concentration range of 0.25-1.50 M H2SO4 and it was found that the reaction progressed in diffusion controlled way depending on H2SO4 concentration.