Dredge Safety
The objective of the work reported here was to examine, analyze and evaluate the safety hazards which affect mining dredge workers. The safety hazard consideration involved design and environmental hazards as well as those related to dredge operation and maintenance. It included shore-based equipment which supports the dredge or which is in the production sequence […]
How to Dissolve Galena
There has been growing concern about the adverse effects on the environment associated with high temperature processing of galena. Because of the difficulties encountered with conventional smelting, the use of hydrometallurgical techniques for lead processing has received considerable attention in the past few years. With hydrometallurgical processing, sulfur dioxide is not produced and lead-bearing particles […]
Desliming Equipment
Filter Presses Filter presses are batch units that use higher than atmospheric pressures and a series of filter plates to separate the solids from the liquid. They are also called pressure, plate-and-frame, or press filters. Although this type of device is well known, it has had little attention or application in the U.S. minerals industry […]
Desliming
The disposal of wet fine-grained wastes from a milling operation can be a difficult challenge for the plant operator. He or she must consider the stability of the material after deposition, environmental consequences, and, above all, economic constraints. Waste material or tailings with a minimum of material smaller than 200 mesh (0.0029 in) can be […]
Ceramic Materials are Resistant to Nitric Acid
New mineral processing techniques being investigated by the Bureau of Mines and others, such as processing at elevated temperatures, leaching with acids and bases, chloride leaching, and dissolution in fused salt baths, may require the use of construction materials that, have good corrosion resistance. One example is the construction material needed to line leaching vessels […]
How Minor Element Affects Copper Matte Smelting
Minor-element interactions in equilibrated samples of copper matte and silica-saturated iron silicate (fayalite) slag have been studied by the Bureau of Mines to gain basic and fundamental scientific information that will support the mineral industry’s effort to improve productivity, increase energy efficiency, and reduce undesirable environmental impacts. This work was carried out as an adjunct […]
Conveyor Belt Service Machine
Design, fabricate, and test a machine capable of operating in coal seams 48-inches and thicker that can reduce the time, expense, and injury potential inherent in extending and retracting mine-wide section belt conveyors, while eliminating the need to use additional machinery or equipment in accomplishing such moves. The Problem Many underground coal mines use a […]
Preventing Chromium Leaching
This report presents the results of research aimed at evaluating and preventing the leaching action that may result from the disposal of waste ferrous slags into landfills where they can be subjected to acid precipitation. Waste slag constitutes a large potential source of chromium contamination of ground waters, particularly under the enhanced leaching action of […]
HCl Leaching Reactor Design
In the clay-HCl miniplant, leaching sized, calcined kaolin with HCl was carried out in 50-gal, glass-lined continuous, stirred tank reactors (CSTR’s). Originally four reactors arranged in a cascade configuration were used, but experience showed that acceptable alumina extraction was obtained with three reactors. The fourth reactor was kept on a standby basis. The reactors were […]
Aluminum Chloride Hexahydrate from Kaolinitic Clay
There has been considerable interest in developing methods to economically produce cell-grade alumina from nonbauxitic materials. In the United States, this interest stems principally from a lack of sufficient bauxite deposits suitable for Bayer processing. In 1973, the Bureau of Mines initiated a program to study the options available for recovering alumina from domestic resources. […]