Pyrite Buffer in Soil
The Gunnison, Colorado, tailings provide an example of the chemical reactions across the interface with soils rich in pyrite but low in calcite. In this case, the retardation of trace components is determined primarily from the Eh controls and less from the pH (Johnson, 1985). The compositions of groundwater from wells in the vicinity of […]
Effect of Cupric Ammine on Gold Dissolution Rate
The dissolution of gold in ammoniacal solutions cannot take place in the absence of oxidants. Cupric ammine can act as an oxidant in this system according to Equation 3. The effect of cupric ammine concentration on the dissolution rate of gold was investigated in a solution of 0.6 M total ammonia concentration (0.1 M (NH4)2SO4 […]
Autogeneous Grinding VS Steel Grinding Media in Flotation
In grinding, the use of steel media in a rod/ball mill circuit clearly diminishes the subsequent froth flotation performance over purely autogenous grinding. The use of recycle water in grinding also clearly diminishes the subsequent froth flotation performance associated with fresh tap water. Some of these flotation deficiencies are recoverable by using stronger collectors at […]
Magnesioferrite
In the case of pellets it was observed that incremental additions of olivine to any of a series of pellet concentrates invariably caused the pellets to become progressively more ferromagnetic after induration. At first, it was assumed that what little magnesioferrite formed in such pellets stabilized magnetite, a comparable spinel structure, in solid solution. However […]
Cone Crushers: Types, Benefits, and Applications
Introduction Compared to the gyratory crusher, the cone crusher is characterized by its higher speed and a flat crushing chamber design which is intended to give a high capacity and reduction ratio for materials suitable to this type of processing. The aim is to retain material longer in the crushing chamber to do more work […]
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 […]
Longwall Mining Method and Design
Studies estimate that 156 billion tons of coal, representing 68 pct of the minable reserves in the United States, is subject to multiple-seam mining. Historically, room-and-pillar mining has dominated coal production, and this mining method has been the focus of most multiple-seam research. Advances in Longwall Mining Method have made this system more economically attractive […]
Grouted Rock Bolting Procedure
Since the introduction of rock bolts 40 years ago, their use to support and stabilize openings in U.S. mines has steadily increased. The number of roof falls has been significantly reduced where rock bolts have been installed, and they are now the primary support required by the Mine Safety and Health Administration (MSHA) in most […]
In Situ Copper Leaching Operations Hydrologic Design
In situ leach mining (ISLM) is an advanced selective mining technique used for the exploitation of copper oxide deposits. ISLM involves the injection of a solution into a deposit, the dissolution and mobilization of target metals, and the recovery of this solution for processing. The vast supply of raffinate, a sulfuric acid by-product resulting from […]
Thiosulfate Leaching of Gold from Copper Bearing Ores
Cyanide has been used in the mining industry for gold and silver recovery for almost a century. It is cost-effective and achieves excellent extractions from a wide range of ores. However, considerable interest has been expressed in non-cyanide lixiviants since the early 1980’s. In addition to environmental considerations, several factors have influenced the search for […]