Leaching Method for Recovering Silver & Manganese
In support of its goal of maintaining an adequate supply of minerals to meet national economic and strategic needs, the Bureau of Mines has investigated the feasibility of in situ and heap leaching to recover manganese from low- and medium-grade domestic manganese deposits and to also recover the silver found in some of these manganese […]
Cobalt Flotation Recovery
Cobalt Flotation Studies were conducted on ores from the Viburnum trend in southeast Missouri. The Viburnum trend deposits occur along the flank of the St. Francois Mountains. Ores of the Viburnum trend are characteristically complex mixtures of the sulfide minerals galena, PbS; sphalerite, ZnS; chalcopyrite, CuFeS2; pyrite, FeS2; marcasite, FeS2; and the cobalt-nickel mineral siegenite, […]
Rock Drag Cutting
The Bureau of Mines, in its continuing efforts to improve productivity and enhance the workplace environment of hard-rock underground mines, has investigated mechanical excavation techniques and in particular drag cutting techniques to achieve these goals. Two fragmentation techniques that use drag cutters have found some success in the mining industry: the kerf-core technique and, the […]
Best Air Sparging System for Column Flotation
Objective: Provide a low-maintenance, reliable means of generating bubbles and controlling bubble size for column flotation. Approach: Commercial sparger systems used in flotation columns to process minerals provide only limited means of controlling the size of bubbles generated and the rate of air injection. Generally, these limitations are a detriment to flotation performance, particularly in recovering coarse […]
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 […]
Zeolite – Natural and Synthetic
Zeolites are crystalline aluminosilicates of the alkaline and alkaline-earth metals. They possess many desirable ion- exchange, molecular sieving, and catalytic properties, which make them valuable mineral commodities. Synthetic zeolites have been used for over 25 yr in commercial processes, but only recently have natural zeolites been viewed as potentially valuable mineral commodities. Because of this […]
Water Filtration by MgO Magnesium Oxide
Suspended solids are a common impurity in mine water. Mines rely mainly on flocculation and settling for solid removal, but this can be unreliable owing to seasonal variation in water temperature, runoff, and changes in the character of ores being mined. Filtration is often needed to provide sufficiently pure water to meet mineral processing requirements […]
Fuse Wire Arc Tester
When certain insulating materials are decomposed by heat, highly explosive gases can be released. These insulating materials cannot be used within enclosures containing high-voltage circuits because they may be subjected to destructive electrical arcing. The commonly used method in the United States for determining if materials are highly resistant to electrical tracking is the CTI. […]