In many instances, Diatomaceous Earth (DE) filtration could be considered a relatively recent technology. In the late 1800’s there were many references to the use of DE in small scale filtrations and in most instances these were laboratory curiosities. The use of DE in the sugar industry was proposed in the 1880’s, but this was … Read more
As part of its effort to reduce the need for strategic minerals through conservation and to reduce the capital and energy requirements of mineral processing, the Bureau of Mines has investigated a method for preparing ferrochromium alloys containing less than 2 percent carbon. This method will conserve chromium and should reduce the capital and energy … Read more
The Federal Bureau of Mines investigated extraction of lithium from non-conventional resources in keeping with its goal of maximizing minerals and metals recovery from domestic resources in order to assure an adequate supply of minerals to meet national economic and strategic needs. This report describes the results of bench-scale studies on the processing characteristics of … 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
The objective of this investigation was to reduce toxic Cr6+ in various waste processing liquors to less toxic Cr3+ while simultaneously removing copper. In addition to recovering a valuable copper product, removal of copper and reduction of Cr6+ in these liquors will substantially decrease the chemical demand and increase efficiency in waste treatment operations associated … Read more
The lack of domestic reserves of rutile and high-grade ilmenites to accommodate the projected increased demand for TiO2 has prompted the Bureau of Mines to investigate methods for recovering titanium from lower grade deposits. In addition, rapid depletion of domestic high-grade iron ore deposits constitutes a growing problem. The United States is well endowed with … Read more
Etching solutions containing hexavalent chromium ions (e.g., chromic acid) are used in brass finishing, printed circuit board etching, preparation of plastic for plating, anodizing, and various other industrial surface treatment operations. As the solutions are used, hexavalent chromium ions are reduced to their trivalent state, contaminants accumulate in the solution, and the effective acid concentration … Read more
Dielectrophoresis, or dielectric separation, can be defined as the separation of particles according to their dielectric properties. Directly related to the dielectric properties of a particle is the particle’s dielectric constant (K). The difference in K of minerals is often much greater than the differences in density, magnetic susceptibility, or electrical conductivity. To date, several … Read more
What if the shaft were much larger, say, 300 m in diameter, or 3000 m, is the above approach to aquifer depressurization still valid? Is it feasible and practical to use wells to reduce the water inflow to a deep mine? If so, can the evaluation approach used in this paper be utilized? I believe … 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