Rock Stability Tester
Aid mine workers in detecting hazardous roof conditions in underground mines by developing a method of roof sounding which supplements or replaces the traditional roof sounding technique where the miner relies on experience to determine whether or not the rock is sound. The Bureau of Mines developed an electronic roof sounding device that acoustically determines […]
Magnesium Oxide to Remove Metals in Water
Conventional practice for treating mine drainage and other water sources contaminated with heavy metals is lime precipitation and settling of the hydrous oxides. This produces a voluminous toxic sludge that results in another type of disposal problem. In addition, settling of the precipitated hydrous oxides often does not produce sufficiently pure water to meet statutory […]
Gold Trommels & Gold Scrubbers
Gold Trommels & Scrubbers are noted for economy and efficient performance in cleaning sand, gravel, crushed stone and various ores. These machines are ruggedly constructed and are designed for excellent results with a minimum of water, power and maintenance. Time and again users report lower cost per ton with Gold Trommels & Scrubbers. Gold Trommels […]
Rock Cutting Equipment
Mechanical excavators were introduced for soft rock cutting at the time of the industrial revolution. The early machines date back to mid 1800’s and were developed for rapid excavation of tunnels and to increase production in the mining environment. The early radial or drag type tools were very primitive and made of hardened steel and […]
Air Decking to Increase Fragmentation in Blasting
Better Air Decking using the Saver Plug, offers a reduction in fly rock, vibration, drilling costs, and the volume of explosives used in blasting. It is used across all sectors of the mining industry, including underground horizontal hole blasting. Increased fragmentation and cast percentage is achieved with the same or reduced Powder factor. All of […]
Drying Coal by Microwave
Fundamental problems exist with the drying of fine coal. The moisture content of fine coal after mechanical dewatering is often too high to allow the coal to be added directly to the coarser (plus ¼ in) fractions and it must be further dewatered. Also, fine coal is lost and expelled with sludge in most current coal […]
Hydrostatic Bearing Type Center Mechanism
Development of the Hydrostatic Bearing Mechanism evolved from the caisson thickener design. Conventional thickener mechanisms are driven by gearing which rides on ball or roller type anti-friction bearings. It would not be feasible to use this method of support with a very large diameter bearing, especially with high torque, vertical and unbalanced loads. Additional stresses […]
Dewatering Clay
Phosphatic clay waste is one of the principal waste products resulting from the mining and benefication of Florida phosphate ore. This waste material, which is comprised of ultrafine particles (70 pct less than 1 µm), responds poorly to conventional solid-liquid separation techniques and is currently disposed of by impoundment behind earthen dams. The overall natural […]
Marked Ball Wear Test
Marked ball wear testing described in a 1948 paper by Norman is an invaluable test method to measure relative and/or absolute wear rates of balls under identical mill operating conditions. Preparation of balls at Armco consists of drilling a 6.4 mm diameter hole in each ball with an electrical discharge machine (EDM), cleaning, weighing, placing […]
Flameless AAS Atomic Absorption Spectroscopy
Flameless AAS provides a means to increase flame AAS sensitivity, by up to 200 times. Interferences from aqueous leachates and digestates are so great, however, that flameless AAS has found application mainly after organic extraction. Thereby, the analytical sensitivity is increased far beyond that of the SX/flame- AAS methods. Interferences Interferences from other elements have […]