Increasing the relative motion of the electrolyte with respect to the electrode surface has long been recognized as a means by which the mass transport of ions to the electrode can be increased to allow operation at higher current densities. Basic theories and early experiments were discussed by Nernst, Brunner, Lin, Denton, Gaskill, and Putnam, … Read more
The object of this research was to investigate procedures for recovering copper from chloride solutions as part of a larger program involving the application of chlorination techniques to copper and other base metal sulfide concentrates. In the first step of the process, a pelletized chalcopyrite concentrate is chlorinated in a vertical shaft countercurrent chlorinator. Molten … Read more
The Bureau of Mines strives continually toward its goals of maximizing minerals and metals recovery from primary and secondary domestic resources, and reducing energy requirements of mining and mineral processing. This investigation to improve zinc electrolysis by separating and recovering the currently discarded cobalt and nickel found in Missouri zinc concentrates is among the Bureau’s … Read more
One aim of metallurgy research within the Federal Bureau of Mines is the advancing of metals and minerals processing technology to foster the overall goal of maintaining an adequate supply of minerals and metals to meet national economic and strategic needs. This report describes part of a research effort aimed at increasing the utilization of … Read more
In the quest for technological improvements in the extractive metallurgy of zinc, some efforts have been made to develop a one-step pyrometallurgical process for direct reduction of zinc sulfide to metallic zinc. The earliest endeavors were those of Eulenstein in 1912 and Peterson in 1913 who both attempted to reduce zinc sulfide with iron in … Read more
During electrolysis, metal was produced from solid lead chloride in contact with the cathode rather than from lead in solution. Relatively high current densities—up to 300 amp/ft²-were possible when operating in this way. Primary lead is now usually produced from sulfide concentrate by a smelting process that involves sintering, blast furnace reduction with carbon, and … Read more
Electrowinning is defined as the cathodic deposition of metal, in this example copper, from a copper bearing solution by the passage of an electric current current using an insoluble anode. For copper the electrowinning reaction reaction is: CuSO4 + H2O ⇒ Cu + ½O2 + H2SO4 The overall reaction is the combination of two electrochemical … Read more
The recent increase in anode copper production at the Noranda smelter placed an additional load on the Montreal East plant of Canadian Copper Refiners Limited. The consequent increase in the amount of anode slimes led to a careful consideration of the various methods of slimes treatment. Characteristics of the Slimes Anode slimes are made up … Read more
Cement copper production in the United States has increased during the past few years, principally because more submill-grade material from open-pit operations is being leached in waste dumps. Since 1960, the cement copper annual growth rate has been about twice the rate for primary copper. If this trend continues, annual production of copper from cement … Read more
The electrolyte in-between the active electrodes must be purged with higher velocities to maintain a high concentration of the desirable copper ion in the liquid film adjacent to the cathode and the sulfate ion in the liquid film at the anode. This higher velocity also carries away from the cathode the undesirable impurities released from … Read more