Metal separations and metal recoveries by ion exchange and solvent extraction of their thiocyanate complexes are widely practiced in analytical chemistry as well as in some industries. Consequently, a critical review of the chemistry of thiocyanic acid and thiocyanates is presented in the second part with the aim of providing a clearer understanding on the … Read more
One of the most frequently asked questions is: “Where is copper (price and usage) going?” I will not attempt to forecast either the future price of copper or the future growth of the copper industry; rather I would like to discuss the current trends experienced in the smelting and refining terms and conditions for sales … Read more
The need to move large tonnages of slurry has grown as mines have become larger. As existing tailing depositories are filled up, new mines developed, or environmental requirements dictate, it becomes necessary to transport tailing particularly over longer distances. There are two basic types of slurry transport systems, packed flow and slack flow. Packed flow … Read more
We have been conducting research on methods for beneficiating platinum-palladium ores from the Stillwater Complex, Montana. The Stillwater Complex contains the only known major deposits of platinum-palladium ores in the 48 contiguous States. Exploration by Johns-Manville Corp. (Manville Corp.) has resulted in the delineation of an approximately stratigraphic zone (J-M Reef) rich in platinum- and … Read more
Environmental Setting A basic understanding of the climatic characteristics, geology, surface and groundwater hydrology conditions together with the physical and chemical characteristics of selected mill tailings deposits will aid in understanding the environmental problems associated with tailings disposal and restoration. The Black Hills region is in the mid-latitudes which have a prevailing westernly airflow. The … Read more
A Tower mill consists of a vertical grinding vessel provided with a central shaft screw-shaped impeller. The screw impeller rotates in such a way as to move the grinding media upward through the central portion of the grinding compartment and downward through the outer portion. Grinding media such as steel balls, ceramic pebbles, or natural … Read more
Dewatering refuse tailings with a belt filter press has not been widely accepted by the Coal Industry. Part of the problem lies with the highly variable characteristics of the refuse solids themselves. The belt filter press, like other dewatering devices, is highly dependent on these dewatering characteristics. The purpose of this study was to examine … Read more
Tungsten carbide (WC) is chemically a binary compound of tungsten and carbon in the stoichiometric ratio of 93.87% tungsten and 6.13% carbon. However, industrially the term usually implies cemented tungsten carbides (CWC); a sintered powdered metallurgical product consisting of very fine grains of pure tungsten carbide bound or cemented together in a cobalt matrix. The … Read more
Numerous low-grade gold-silver ore deposits are being mined and milled throughout the Western United States. In addition to gold and silver, many deposits contain as much as 15 ppm of mercury. During cyanidation, 10 to 30 pct of the mercury and 85 to 90 pct of the gold are typically solubilized. The reactions for gold … Read more
Over 80 pct of U.S. potash production comes from evaporite deposits near Carlsbad, NM. Most potash products are concentrated by flotation, selective dissolution of the gangue minerals, or precipitation of the mineral from hot brine. The majority of sylvinite ores, mixtures of KCl and NaCl, mined in New Mexico, are processed in grinding, desliming, sylvite … Read more