Water Jet Cutting to Reduce Dust
Objective: Use water-jet-assisted cutting technology to reduce the exposure of mine workers’ to respirable dust. Approach: Install water-jet-assist on mining machines and evaluate its impact on respirable dust. How it Works Water-jet-assisted cutting involves a mechanical cutting bit working in combination with a moderate pressure (generally up to 10,000 psi) water jet directed just in front of, […]
Cutting Rock by Water Jet
The use of water jets to augment mechanical rock cutting has advanced greatly since the discovery a decade ago that water jets diminish the forces acting upon drag bits cutting in strong rock. Other research workers cutting in a wide variety of rock types and with various geometries of bits unanimously confirmed that substantial benefits […]
Monorail Bridge Conveyor System
The Bureau of Mines has sponsored numerous high-risk research programs over the past decade to improve productivity and health and safety in underground coal mining by advancing state-of-the-art continuous face haulage systems, These systems are designed to move coal nonstop from the continuous miner to the next stage of rail or belt haulage (approximately 500 […]
Underground Coal Mine Design Procedure
A systematic, comprehensive, balanced approach is presented for underground coal mine design, capable of being standardized and generalized. This approach epitomizes professionalism and must preceed the physical product. Design involves a varied senior staff and requires extensive selective input data. Engineering follows a total systems approach, operating in and for a constricting geologic setting, heavily […]
Magnetite Concentration Methods
Magnetite is the most strongly magnetic of all minerals, and it is therefore natural that the earliest application of magnetism to ore dressing was for its concentration from gangue. Magnetite ores occur in large bodies in almost all countries, and on account of the high iron tenor of the pure mineral, and the ease with […]
Controlled Blasting
Rock fragmentation by explosives is presently the most inexpensive process available to the hardrock mining industry. The challenge remains, however, to control the explosive energy to optimize fragmentation produced by blasting and minimize the deleterious effects associated with the use of explosives. These harmful effects are often simply stated as damage, which regroups damage to […]
Infill Drilling Program Design
An exploration process is normally consisted of four major phases: regional reconnaissance, detailed mapping, sparse drilling, and infill drilling. Regional reconnaissance focuses on promising areas for a given type of ore deposit by using geological, geochemical, and geophysical data. Once one or more areas are selected, a detailed mapping program will be enacted in order […]
In Situ Mining Well Construction
The objective for this U.S. Bureau of Mines (USBM) research is to evaluate construction and completion methods and costs for vertical in situ copper mining wells to depths of up to 1100 m (3600 ft). Appropriate construction materials and costs have been determined for well equipment, casing, drilling, cementing, and completion. A “deep” single ore-zone […]
Water Powered Jackleg Drills
The idea of using the energy of water (hydropower) for the purpose of deep-level mining has its origins in South Africa. It stems from necessity and practical considerations. With a constant increase of the depth of mining, ventilation and cooling requirements made it essential to chill the service water sent underground. Water in the shaft […]
Pilot Scale Testing Coal Air-Lift Hydrohoist
Primary underground coal transportation systems, such as conveyor belts, rail haulage, and mechanical hoists, have numerous inherent safety hazards. During the period 1990 to 1992, 12% of all the reported 31,266 accidents that occurred at underground coal mines were associated with powered haulage, and 52% of all haulage accidents, including surface areas of underground mines, […]