No abstract

No abstract

One of the major problems in copper-producing countries is the treatment of the large amount of copper slag or copper flotation waste generated from copper slag which contains significant amounts of heavy metals such as Cu, Zn, Pb and Co. Dumping or disposal of such large quantities of flotation waste from copper slag causes environmental and space problems. In this study, the treatment of flotation waste from copper slag by a thermal method and its use as an iron source in the production of inorganic brown and black pigments that are used in the ceramic industry were investigated. The pigments were produced by calcining different amounts of flotation waste and chromite, Cr2O3, ZnO and CoO mixtures. The pigments obtained were added to transparent ceramic glazes and porcelainized tile bodies. Their colours were defined by L*a*b* measurements with a spectrophotometer. The results showed that flotation waste from copper slag could be used as an iron source to produce brown and black pigments in both ceramic body and glazes.

Copper waste is iron-rich hazardous waste containing heavy metals such as Cu, Zn, Co, Pb. The results of leaching tests show that the concentration of these elements exceeds the Turkish and EPA regulatory limits. Consequently, this waste cannot be disposed of in its present form and therefore requires treatment to stabilize it or make it inert prior to disposal. Vitrification was selected as the technology for the treatment of the toxic waste under investigation. During the vitrification process significant amounts of the toxic organic and inorganic chemical compounds could be destroyed, and at the same time, the metal species are immobilized as they become an integral part of the glass matrix. The copper flotation waste samples used in this research were obtained from the Black Sea Copper Works of Samsun, Turkey. The samples were vitrified after being mixed with other inorganic waste and materials. The copper flotation waste and their glass-ceramic products were characterized by X-ray analysis (XRD), scanning electron microscopy and by the toxicity characteristic leaching procedure test. The products showed very good chemical durability. The glass-ceramics fabricated at 850 degrees C/2 h have a large application potential especially as construction and building materials.

The aim of this study is to investigate the effects of conditioning with NaCl and HCl solutions on removal of Ni 21 ions from aqueous solutions using natural clinoptilolite. Batch studies were performed to evaluate the effects of various parameters such as chemically conditioning, adsorbent amount, contact time, initial pH of the solution, mixing temperature, and initial metal ions. The results clearly showed that the conditioning improved both the exchange capacity and the removal efficiency. Langmuir, Freundlich, Temkin, and Dubinin-Kaganer-Radushkevich (DKR) isotherm models were adopted to describe the adsorption isotherms. Adsorption isotherms of Ni 21 ions could be best modeled by Langmuir equation. Three simplified models including pseudo-second-order, intraparticle diffusion and Elovich were used to test the adsorption kinetics. These results indicate a significant potential for the natural and conditioned clinoptilolites as an adsorbent/ionexchange material for heavy metal removal.