Electrolysis of Gold from Filtration Waste by Means of Mechanical Activation
The intensification of the gold thiourea leaching from a filtration waste (Kosice, Slovakia) using mechanical activation as the pretreatment step has been studied. The leaching of “as-received“ sample in an acid thiourea solution resulted in 65 % Au dissolution. However, after mechanical activation in a planetary mill 99 % of the gold was leached. The optimum redox potential for electrolysis is in the range 500-523 mV for the gold extraction 99.79 % from the mechanically activated sample. The mechanical activation resulted in an increase of the specific surface area of the waste from 0.7 m 2 g -1 to a maximum value of 13.5 m 2 g -1 . The physicochemical changes in the filtration waste as a consequence of mechanical activation had a pronounced influence on the subsequent gold extraction.
Mechanochemistry in Nanoscience and Minerals Engineering
Mechanochemistry and Nanoscience.- High-Energy Milling.- Selected Identification Methods.- From Minerals to Nanoparticles.- Mechanochemistry in Minerals Engineering.- Applied Mechanochemistry.
Leaching of antimony and mercury from mechanically activated tetrahedrite Cu12Sb4S13
Abstract In this study the physico-chemical transformations and leachability of antimony and mercury from tetrahedrite concentrate mechanically activated by intensive grinding in a planetary mill were investigated. It has appeared that the leaching of antimony and mercury from tetrahedrite in alkaline solution of sulphide solution is a structure-sensitive reaction. The temperature dependence of both reactions investigated in the temperature interval 298–363 K has shown that these reactions do not involve any change in mechanism. The experimental activation energies found in this connection were E = 7 kJ mol −1 for the leaching of mercury and E = 33 kJ mol −1 for the leaching of antimony.