Sample Preparation Method for Cyanide Shake Assay of Gold
A series of tests were undertaken for the Aurora Partnership-Aurora Project to solve inter-laboratory variations in the analyses of blast hole cuttings. Initial concern was centered on the probability that free gold occurrence was resulting in erratic results for the mine’s cyanide shake assays and outside laboratory fire assays. Test Procedure A 50 kilogram bulk […]
Leaching & Recovery of Phosphoric Acid Gallium & Silver
Treater Dust is the name given to the material that is collected in electrostatic precipitators used for off-gas cleaning of elemental phosphorus furnaces. Elemental phosphorus is made by reacting phosphate ore, silica, and coke in an electric furnace, as shown by these reactions: 2Ca3(PO4)2 + 6SiO2 → P4O10 + 6CaSi03 P4O10 + 10C → P4 + 10CO […]
Drag & Hoist Ropes of Dragline Performance
Typical dragline rigging includes several sets of ropes: hoist ropes, drag ropes, dump ropes and boom suspension ropes. The drag and hoist ropes contribute most to the dragline operating cost, and significantly influence dragline productive time. Both work in very difficult conditions and wear out rapidly. As a result frequent rope changes are required at […]
Effect of Sample Storage on Kinetics of Pyrite Oxidation
Pyrite oxidation has been studied extensively in relation to its role in sulfide mineral flotation. Although pyrite usually lacks economic value in polymetallic ores, it generally acts as an undesirable constituent which complicates the separation of valuable minerals. This mineral is also considered to be the main source of acid mine drainage. The formation of […]
Synthetic Serpentinite
Serpentinite minerals are available in large quantities from asbestos mining activity. The granular or fibrous serpentite, at temperatures greater than 700°C, will recrystalize into olivine, forsterite and enstatite. These minerals have been used and studied for decades and are environmentally safe. The thermal process changes the composition and properties of the original mineral. Therefore, the […]
How to Separate Zinc Cobalt & Nickel by Solvent Extraction SX EW
An acid mine drainage sludge sample containing 3.6% Mn, 0.18% Ni, 0.15% Co and 0.39 % Zn was obtained from the central part of West Virginia and leached with sulfuric acid at pH 3 and at room temperature. Air was bubbled through the leach solution to precipitate the iron content from the solution at pH […]
Dense Media Properties on the Performance of a Dense Medium
The effect of the stability and rheological properties of magnetite dense medium on the separation performance of a 6″ dense medium cyclone (DMC) is studied with the use of fine density tracers. The tests in which different size fractions of magnetite are used to prepare the dense media reveal that at low medium densities (<1.5 […]
Kaolin Filter Aids
Efficient filtration of fine kaolin particles plays a crucial role in processing of raw kaolin to a marketable product. Oftentimes, filtration is the rate controlling step of the whole process. As a consequence, plant production is dependent, to a great extent, on the rates being achieved in filtration.. Variation in particle size, coupled with varying […]
Low Temperature Pressure Oxidation
Aqueous pressure oxidation at low temperature, although desirable from a process engineering and operations point of view, presents unique problems when temperatures approach 160°C (320°F). In developing the pressure oxidation process for the Lone Tree Mine, elemental sulfur formation and agglomeration with pyrite proved to be a problem. The Lone Tree Mine currently operates a […]
Refractory Gold Ore Flash Roasting
Roasting of refractory gold ores has the primary goal of oxidizing sulfides and organics to improve gold recoveries prior to leaching. Commercial installations currently utilize bubbling and circulating fluidized beds. The principle of flash roasting is aimed at a more cost effective method of whole ore roasting for large throughput applications. Results of pilot plant […]