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 […]
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 […]
Heap Leaching Gold & Silver Ores
An investigation of a particle agglomeration technique as a means of increasing the percolation rate of leaching solutions through heaps of clayey or finely crushed, low-grade, gold and silver ores. Bench-scale and pilot-scale experiments conducted on different ores indicated that the percolation rate of cyanide leaching solution was enhanced markedly by mixing the ore with […]
Gold Heap Leaching Practices
Heap leach gold recovery techniques are employed at Ortiz. Caustic cyanide solutions are sprayed onto crushed rock piles, dissolving the metallic gold from within the rocks and carrying it out as a ‘pregnant’ gold containing solution. The solution is then passed over carbon particles which the gold preferentially precipitates upon. The gold loaded carbon is […]
Copper Cementation for Small Scale Operations
We studied the precipitation of copper from dilute acidic sulfate solutions using shredded automobile scrap in a rotary drum. The tests established that the scrap in the rotary drum precipitated copper faster and more completely than shredded, detinned, tinplate scrap in a launder, with comparable iron consumption. Although power is required to rotate the drum, […]
Uranium Acid Leaching
Mechanism of Uranium Leaching: Uranium leaching with sulphuric acid is a complex process governed by chemical dissolution, and the oxidation of uranium. It is controlled by surface etching, diffusion, and mass transfer within the ore. The physical parameters are in turn controlled by the physical properties of ore, and the ore size. The leaching process may […]
Cyanide Leaching Platinum Catalytic Converter Chemistry
Previous research by the U.S. Bureau of Mines showed that autoclave cyanide leaching of used automobile exhaust catalysts for recovery of platinum group metals (PGM) was technically feasible. This work involves a more detailed investigation of the chemistry of the dissolution of PGM in cyanide solutions. The PGM species in solution were identified by ultraviolet […]
Thiourea Gold Leaching
The use of thiourea, (CS(NH2)2 as a complexing/extracting agent for gold and other precious metals has shown promise for implementation in the mining/metals industry. Laboratory testing of this reagent has indicated that a thiourea process for gold extraction has several advantages over conventional processing techniques. The use of cyanide for the extraction of gold from […]
Recover Scrap Battery Lead by Electrolysis
One objective is the secondary recovery of metals, minerals, and other values from waste products and the development of uses for them. In line with this objective, research was initiated to develop an environmentally acceptable alternative to the pyrometallurgical processes currently used by the secondary lead industry. These processes produce 45 pct of this country’s […]
Carbon in Pulp Plant
Sslurry at a rate of approximately 3.785 cu. m. per minute (1,000 GPM) is placed in contact with activated carbon. A simplified flow-sheet of the CIP Plant is shown in Figure 2. For years it has been known of the affinity of activated carbon to adsorb preferentially the gold and silver in cyanide complex form. […]