Search Results (2)

A strategy to determine the effect of Cd²⁺ on the electrodeposition of copper from a copper electrolyte by cyclone electrowinning is presented. The concentration of Cu²⁺ in the copper electrolyte with different Cd²⁺ concentrations was determined by atomic absorption spectrometry (AAS). It indicated that the current efficiency, the rate of electrodeposition, and the rate copper electrodeposition decreased with the addition of Cd²⁺ in the three stages of electrodeposition. The current efficiency declined from 99.6 to 79.2% and the copper electrodeposition rate declined from 52 to 40% in the first electrodeposition. The current efficiency had no significant change, and the copper electrodeposition rate declined from 88 to 77% in the second electrodeposition. The current efficiency declined from 72.6 to 40.3%, and the copper electrodeposition rate was all at 99% in the third electrodeposition. The influences of the Cd²⁺ concentration on the purity and morphology of cathode copper were investigated. The effect of Cd²⁺ concentration on the purity and morphology of cathode copper was also studied. In the three-stage electrodeposition, the addition of the Cd²⁺ concentration mainly affected the microstructure of the cathode copper, but it had little effect on the purity of the cathode copper. The higher the amount of Cd²⁺, the rougher the morphology of the cathode copper and the larger the gap between the grains; the higher the amount of Cd²⁺, the lower the electrodeposition rate and current efficiency, though the reduction was small. Full article

The rigorous environmental requirements promote the development of new processes with short and clean technical routes for recycling tellurium from tellurium-bearing sodium carbonate slag. In this paper, a novel process for selective recovery of tellurium from the sodium carbonate slag by sodium sulfide leaching, followed by cyclone electrowinning, was proposed. 88% of tellurium was selectively extracted in 40 g/L Na₂S solution at 50 °C for 60 min with a liquid to solid ratio of 8:1 mL/g, while antimony, lead and bismuth were enriched in the leaching residue. Tellurium in the leach liquor was efficiently electrodeposited by cyclone electrowinning without purification. The effects of current density, temperature and flow rate of the electrolyte on current efficiency, tellurium recovery, cell voltage, energy consumption, surface morphology, and crystallographic orientations were systematically investigated. 91.81% of current efficiency and 95.47% of tellurium recovery were achieved at current density of 80 A/m², electrolyte temperature of 45 °C and electrolyte flow rate of 400 L/h. The energy consumption was as low as 1.81 kWh/kg. A total of 99.38% purity of compact tellurium deposits were obtained. Therefore, the proposed process may serve as a promising alternative for recovering tellurium from tellurium-bearing sodium carbonate slag. Full article