Alireza Mohadesi; Rasool Roohparvar; Nahid Yaghoobi
Abstract
The use of additives is a standard method in both electrowinning and electrorefining of copper. They have multiple roles in the electrodeposition of copper. They are diffusion barriers and/or complexing agents for copper. In addition, they can perform other important roles as well. Thiourea has been ...
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The use of additives is a standard method in both electrowinning and electrorefining of copper. They have multiple roles in the electrodeposition of copper. They are diffusion barriers and/or complexing agents for copper. In addition, they can perform other important roles as well. Thiourea has been extensively used as an additive in industrial copper electrorefining processes. The effect of thiourea on anode passivation, nodule formation in the cathode, and polarization of copper reduction has been investigated. In this study, we reviewed the most important studies conducted on the mechanism of thiourea effect in the copper electrorefining process, as well as the methods of determination and monitoring thiourea in real samples of copper refinery.
Hooshang Hamidian; Mahbobeh Mosavi Farahbakhsh; Rasool Roohparvar; Mohammad Reza Akhgar
Volume 3, Issue 1 , March 2016, , Pages 42-48
Abstract
The present study shows that the eggshell powder can be used as a natural adsorbent for the removal of alizarin (1,2-dihydroxyanthraquinone) and 2-aminoanthraquinone from aqueous solutions. Experiments were carried out as a function of contact time, concentration, temperature, pH and dosage. The amount ...
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The present study shows that the eggshell powder can be used as a natural adsorbent for the removal of alizarin (1,2-dihydroxyanthraquinone) and 2-aminoanthraquinone from aqueous solutions. Experiments were carried out as a function of contact time, concentration, temperature, pH and dosage. The amount of dye uptake was found to vary with increasing initial solution pH and maximum adsorption was observed at pH=7. The equilibrium was attained in 30 min. The amount of dye uptake (mg/g) was found to increase with increase in dye concentration and contact time. The percent of adsorption was found to decrease with increase in amount of adsorbent. The data were fitted with the Langmuir and Freundlich equations to describe the equilibrium isotherms.
