Several preliminary tests were conducted as a function of drum type (standard, interpole, etc.) and feed temperature. The results from these tests indicate that the deep field of the salient-pole drum vastly outperformed the other magnetic drum circuits. As a result, continued test work focused on the salient-pole drum and rare-earth roll separators. Initial tests … Read more
In accordance with its objective to maximize minerals recovery from secondary domestic resources, Bureau of Mines conducted research on recycling chrome refractory wastes. Since 20 pct of the U.S. demand for imported chromite is used in the production of refractories, primarily for the steel, copper, and glass industries, samples of used chrome-containing refractories from copper … Read more
Objective: To separate complex mineral mixtures according to their dielectric properties. Approach: Develop a laboratory-scale continuous dielectric separator to separate mineral mixtures by exploiting their difference in dielectric properties. How Continuous Dielectric Separator for Mineral Beneficiation Works Dielectric separation is defined as the separation of particles based on their dielectric properties. The uniqueness of the Bureau’s continuous … Read more
Man’s material wealth has usually started with fairly concentrated ore bodies that are mined, beneficiated, refined, and then manufactured into material objects. Following their use and abuse, the objects are discarded and wind up as spots of rust while the sources of raw materials become scattered haphazardly over the lithosphere. Mining and metallurgical sorting practice … Read more
The known domestic reserves of potash feldspar of the quality needed for dinnerware and sanitaryware, as well as for electrical and other industrial porcelain products, are not likely to meet anticipated demand during the rest of the century. However, molybdenite tailings and the prospective tailings from currently undeveloped ore bodies are mineral wastes that have … Read more
This process uses electronic ore sorting or “pre-concentration” as an added step before normal concentration to develop a processing system for the native copper ores. Successful ore sorting can lead to cost reductions in the following areas: Materials handling, and hoisting (if sorting is done underground). Capital and milling operations. Mill tailings disposal, as well as … Read more
Continuously separate mixture of non-magnetic materials (such as scrap, precious metals, or certain ores) at a reasonable cost. Nonmagnetic materials of different densities are rapidly float/sink separated by an augmented lifting force produced in a magnetic fluid (liquid) by the effect of an external magnetic field. The magnetic fluid is a colloidal suspension of magnetite … Read more
WHIM is the short acronym for Wet High Intensity Magnetic Separation. At present, most U.S. iron raw materials are produced from magnetic taconites, which are ground to a nominal minus 270 mesh (53 micrometers), beneficiated by wet low-intensity magnetic separation, and pelletized. The taconite ore bodies generally contain 19 to 25 percent magnetic iron, defined as iron … Read more
In the West, capitalists have expended many millions of dollars developing the low-grade porphyry ores of copper. Half a dozen of these great enterprises have proved to be wonderful commercial successes. They have demanded improved crushing and concentrating machinery and consequently it has been developed. Many improved methods, cheap power, superior business organization, all these … Read more
After considerable experience in connection with the magnetic iron-ores at the South, especially in the Cranberry district of western North Carolina and eastern Tennessee, the writer was led into a thorough investigation of the magnetic separation of iron-ores, and, from this investigation, has gradually been developed a separating machine which it is the purpose of … Read more