Caisson Thickeners
To discuss “Large Diameter Thickeners in the Phosphate Industry” is to discuss large diameter slimes thickeners in general. Since 1948, Dorr-Oliver has supplied these machines to the phosphate industry, originally as a means to reduce pumping costs, but more recently for environmental reasons as well. With the exception of the Caisson thickener, all the types […]
Waste Dump Leaching Copper
To help maintain an adequate supply of minerals to meet national economic and strategic needs, the Bureau of Mines developed a mathematical model that describes acidic ferric sulfate leaching of copper from sulfide ores. The leaching model can aid in maximizing minerals and metals recovery from primary sources by giving operators and management a better […]
Insoluble Anodes for Electrowinning Zinc & Metals
This Bureau of Mines investigation was prompted by the need for a stable anode for electrowinning metals, particularly zinc and copper, from acid solutions. The polarization behavior of Pb-Ag (1 pct Ag) anodes in H2SO4 and fluoride solutions was determined as the first step in the development of such an anode. A Luggin capillary, DC power […]
Effective Strategies for Uranium Acid Leaching in Mining Operations | 911 Metallurgist
Acid leaching has been used in the uranium milling industry since the mid-forties and has accounted for a majority of the production since that time. It is preferred over carbonate leaching because of its greater efficiency in recovering uranium. Consequently much research has been done on the factors which influence the kinetics of the oxidation […]
Recycling of Stainless & Speciality Steel
To reuse chromium, nickel, and molybdenum now lost in stainless and specialty steel-making wastes, and simultaneously to overcome the current environmental problem resulting from landfilling these wastes. A variety of stainless and specialty steelmaking wastes are agglomerated and recharged into the plant’s electric arc furnaces. How It Works Stainless and specialty steel-making wastes such as bag-house […]
Rationed Ball Mill Charging to Improve Grinding Efficiency
Ball Sizes As mentioned earlier, years of operating experience indicated that the maximum ball size for the 2.93 m Climax mills was 76 mm. Application of Azzaroni’s equation confirmed that 76 mm was the correct maximum size. The selection of the second, smaller ball size was made by analyzing historical screen analyses representing composite ball […]
HYL III Direct Reduction Process
The objective of the operator of a direct reduction plant Is to optimize the cost of inputs required to obtain each tonne of DRI. Three major factors affecting the unit cost of the product are iron oxide feedstock, energy, and plant productivity. For the past decade, most direct reduction plants have relied upon pellets as […]
Crystallization of Aluminum Chloride Hexahydrate
As part of its effort to produce cell-grade alumina from clay, the Bureau of Mines investigated the hydrogen chloride gas-sparging crystallization of aluminum chloride hexahydrate (ACH) from aluminum chloride liquor, to provide information for optimizing the crystallization operation. Four parameters important in controlling the crystallization of the aluminum chloride hexahydrate and the concentration of impurities, […]
Dust Controlling Water Sprays
High-pressure shrouded sprays were first tested on a bench to determine air-moving capability and dust collection efficiency. The bench-scale tests indicated that at 500 psi and above, the dust collection efficiency, when sampled downstream of a water eliminator, was about 99 pct for two types of nozzles. However, for the same water flow, the induced […]
Heavy Media Media Recovery – Magnetite & Ferrosilicon
Media Magnetite (Fe3O4) and Ferrosilicon (FeSi) are the most widely used media. Magnetite is used up to a specific gravity of 2.2; a mixture of FeSi and Fe3O4 is used for the range 2.2 to 2.9; above 2.9 FeSi is used alone. Using FeSi, separations up to specific gravity of 3.4 have been made commercially. […]