Sorpční vlastnosti konvertorových kalů

Abstract

This dissertation deals with the issues of metallurgical wastes generated in the wet process of the oxygen converter gas purification. The aim of this work is to assess the suitability of the utilization of converter sludge after removal of water-soluble components as the adsorbent of selected metal ions and to describe the adsorption process. Model solutions of ions Ni(II), Mn(II), Co(II) and real samples of mine waters originating from brown coal mining were selected to verify of the sorption properties. Evaluation of the adsorption capabilities of two pre-treated converter sludges was carried out on the basis of the removal efficiency of selected metal ions from model solutions. Obtained dependences on the pH of model solution, time and initial concentration of model solutions of the observed metal ions were used for the description of the kinetics of adsorption and modeling of adsorption isotherms. The performed experiments showed that the removal efficiency of the observed ions depended on the pH value, the initial concentration of the metal ions and the contact time. The kinetics of adsorption was described by the pseudo-second order model, which showed that the adsorption process is slow. The Langmuir isotherm described the best the adsorption process as regards Ni(II) and Mn(II) ions adsorbed on the converter sludge sample No. 1. The Freundlich isotherm provided the best description in the case of Co(II) ions for converter sludge sample No. 1 and all ions adsorbed on the converter sludge sample No. 2. The verification of the utilization of converter sludges on the real mine water samples showed a significant reduction of the contents of all observed metal ions. This was due to the capture of ions on the surface of the sludge. It was not necessary to adjust the pH value of the mine water for the optimal efficiency of the removal of metal ions. The evaluation of desorption experiments showed that Mn (II) ions are most strongly bound. The possibility of utilization of studied converter sludges for the removal of pollutants from aqueous solutions and wastewaters proved to be real. When applying these waste materials the concentration of the observed metal ions and the pH value in the mine water samples decreased below the permissible limit values set for the discharge of mine water into the watercourses occurred.