Electrowinning of Gold and Silver from Copper Bearing Cyanide
One stage of the cyanide leach process to extract submicron Au particles from disseminated Au ores frequently uses electrolysis. Metals are electrowon from a solution containing Ag, Au, and Cu as cyanide complexes. The electrolyte commonly has Ag and Au concentrations in the 10 to 50 µg/mL range, while Cu, depending on the ore, may […]
Bioleaching Cadmium Sulfide
The applicability of electrochemical techniques in the elucidation of intermediate reactions in the bacterial oxidation of cadmium sulfide minerals has been demonstrated. Furthermore, it was found that the bio-oxidation process was solid-state diffusion controlled. Greenockite (CdS) and hawleyite (CdS) are the most important cadmium minerals, which occur as minor constituents in ores of zinc, lead […]
Gold Room Equipment List
The advantages of the replate system are few, but significant: It greatly reduces the amount of slag produced. Since less slag is produced, the manhours and equipment required to handle the slag are also reduced. Gold losses to slag are proportionally reduced. Steel wool costs are reduced. Steel wool replacement is done twice per year […]
Electrowinning Neodymium – Electrolytic
A rapidly expanding market for Nd-Fe-B permanent magnets has created intense interest in development of a new process for producing neodymium metal. The current industrial process is calciothermic reduction of neodymium fluoride (NdF3), which entails reacting calcium metal with NdF3 at 1,200° to 1,400° C in closed tantalum crucibles. The process was initially developed for […]
Electric Arc Furnace Steelmaking using Scrap
This investigation is part of the Bureau of Mines program to develop technology that emphasizes the reuse of recycled, economically important materials, including iron and steel scrap. In addition, the research helps meet the basic objective of substituting abundant domestic materials for imported strategic commodities such as fluorspar. Scrap Preheating Of the 84.6 million st […]
Elution of Mercury Silver and Gold from Resins
Numerous low-grade gold-silver ore deposits throughout the Western United States have been developed in the past few years. Cyanide leaching and carbon adsorption are generally used to recover the gold. Precious metals and other adsorbed metals are eluted from the carbon with dilute caustic cyanide solutions. The elution process requires elevated temperatures and in some […]
Recover Cobalt in Copper Leach Solution by Ion Exchange
Significant amounts of cobalt, a strategic and critical metal, are present in some secondary sources such as spent copper leach solutions. The United States currently imports over 95 pct of its cobalt supply, much of it from Africa. Development of a process to recover cobalt from readily accessible spent copper leach solutions would help meet […]
Recover Cobalt & Copper from Sulfide Concentrates
Cobalt is a critical and strategic metal because of its essential defence related uses and the high degree of U.S. import reliance for its supply. Currently, the United States does not produce any cobalt from domestic mines. Most of the U.S. supply of cobalt is imported from the African nations of Zambia and Zaire CO-4 […]
Electrogalvanizing using Recycled Zinc
A major problem facing the metals industry in the United States and perhaps throughout the world is the disposition of waste oxide dusts generated at various stages of processing. Storage in landfills has been used most often in the past; but, as more and more of these wastes are being declared hazardous, landfill costs have […]
Fuse Wire Arc Tester
When certain insulating materials are decomposed by heat, highly explosive gases can be released. These insulating materials cannot be used within enclosures containing high-voltage circuits because they may be subjected to destructive electrical arcing. The commonly used method in the United States for determining if materials are highly resistant to electrical tracking is the CTI. […]