Mine Fan Stall – Multiple-Fan Ventilation Systems
Stall or aerodynamic stall of axial-flow fans has long been recognized as an important operational problem in mine ventilation. To develop a technique for characterizing fan stall in multiple-fan ventilation networks, a research project was initiated through the Generic Mineral Technology Center for Mine Systems Design and Ground Control. Considering that fan stall is related […]
Mining Engineers Training Exercises
In the past mining accidents were often a consequence of poorly designed equipment and inefficient mining systems. As mining equipment and technology has become better engineered, safer, and more complex, the frequency of accidents has dramatically decreased, but the proportion of accidents occurring because of decision errors made by the person or persons involved have […]
Assess Permeability Enhancement In Situ Mining
In situ recovery of minerals has great potential as a mining technology to mine deposits that might otherwise be overlooked by conventional techniques. Some hard-rock deposits, however, will not have adequate permeability to permit successful in situ mining and will require permeability enhancement of the rock deposit prior to leaching. The leaching process in this […]
Blast Optimization and Ore Fragmentation Modeling
Blasting plays a key role in all facets of operations. Obviously, drilling and blasting costs are determined by blast design, but the downstream costs that are closely related to blasting results are often treated as separate functions: loading, hauling, cleanup, and crushing and grinding are all heavily influenced. Diggability and bucket fill factor are a […]
Mine Ventilation Recirculation Systems
In many deep mines, the design of a ventilation system to satisfy the airflow requirements might be difficult to implement and expensive to maintain. The problem may even be more serious when the mine workings are dispersed and located a considerable distance from the surface connections. This problem can be alleviated by including a controlled […]
Multi-timbered Wood Crib Supports
Wood cribs are used extensively by the coal mining industry in a variety of applications to stabilize mine openings. The U.S. Bureau of Mines is conducting research to evaluate the load-displacement characteristics of active and passive mine roof support systems, such as wood cribbing, so that the selection and design of these supports are compatible […]
Effects of Non-Darcian Flow
When excavating open-pit mines below the water table, two of the more important water-related problems potentially faced by mine operators is the amount of ground water that could flow into the pit and the effect of pore water pressure on the stability of the highwalls. The ability to predict the nature and magnitude of these […]
How to Select a Sample Size for Ore Evaluation
The semivariogram is a geostatistical tool to show several geological features which are important in mineral deposit evaluation, such as the continuity, size and shape and it is used for many mining purposes. Stationary conditions must be satisfied if the semivariogram calculated in one part of the mineralization is to be used in another part, […]
Placer Sampling and Reserve Estimation
Placer Sampling One of the most difficult tasks associated with placer mining is the sampling of the deposit. More placer projects have failed due to inaccurate assessment of the reserves than to any other reason. Within the realm of placers, those containing valuable minerals with a high unit Value are more difficult to sample than […]
Wood Crib Engineering Method & Design
As voids are created because of the extraction of coal underground, artificial support systems, in addition to roof bolting, often are required to stabilize the mine opening to provide a safe working environment. Various constructions of cribs made from wood timbers are used most often Although these supports are simple in design with a unit […]