Leach mining, in situ

In the early 1990s a new copper extraction technology, known as in situ leach mining, was under investigation. This methodology was proposed, and demonstration plants were lo be constructed to test the proposal. These were jointly sponsored projects by the U.S. Bureau of Mines and two mining companies. If successful, leaching would cut ihe costs and hazards of the traditional open-pit methods currently used. 

Data from in-situ leach mining and restoration of roll-front uranium deposits also provide information on the potential mobility of the waste if oxidizing ground water should enter the repository. Uranium solids probably will be initially very soluble in carbonate ground water however, as reducing conditions are re-established through water/rock interactions, the uranium will reprecipitate and the amount of uranium in solution will again equilibrate with the reduced uranium minerals ... 

Larson, W. C. "Uranium In Situ Leach Mining in the United States" Information Circular 8777 U. S. Dept, of the Interior, Bureau of Mines Washington, D. C., 1978. 

In situ leach, mine water, water-treatment plant solutions... 

ARSON, W. C, 1978. Uranium in situ leach mining in the United Stales. Info. Circ. 8777, U.S. Dept, of Interior, Bureau of Mines. 

In Situ Leaching. Copper and uranium ores are sometimes leached ia place by circulatiag acidified mine water through the underground deposit. This process is known as solution mining. 

Nuclear power plants are based on uranium mined in surface mines, or by in situ leaching. 

Roll-front uranium deposits in confined aquifer systems are amenable to extraction by in situ leach techniques. This method of mining was first tested in Wyoming approximately twenty years... 

This work was sponsored by the Nuclear Regulatory Commission, Office of Nuclear Research. It was conducted at the Pacific Northwest Laboratory, which is operated by Battelle Memorial Institute for the Department of Energy under contract number DE-AC06-76RL0 1830. Additional data and information are given in the report "Aquifer Restoration at In-Situ Leach Uranium Mines -Laboratory Evidence for Natural Restoration Processes," NUREG/CR-3136, PNL-4604, 1983. We appreciate the efforts of Wayne Martin who did much of the laboratory work. 

Deutsch, W. J. Serne, R. J. Bell, N. E. and Martin, W. J. "Aquifer Restoration at In-Situ Leach Uranium Mines ... 

Goddard, J. B. and Brosnahan, D. R. "Rate of Consumption of Dissolved Oxygen During Ammonium Carbonate In Situ Leaching of Uranium" Mining Engineering 1982 34 (11), 1589-1596. 

Aquifers with double porosity (e.g. sandstones with fractures and pore volume) require special considerations with regard to transport modeling even if no reactive mass transport in its proper sense is taken into account. This problem is demonstrated with the following example of an aquifer regeneration in an uranium mine. The ore was leached in this mine by in-situ leaching (ISL) using sulfuric acid. The hydrochemical composition of the water that is in the aquifer after this in-situ leaching process is shown as ISL in Table 40 ... 

White, L. In-situ leaching opens new uranium reserves in Texas. Eng. Mining J. July, 1975, 73-81 (1975). 

Solution mining is the removal of valuable minerals from in-place deposits, by dissolving the mineral in a suitable liquid that is then removed for recovery of the desired constituent. It may also be called in-situ mining or in-situ leaching. Solution mining uses techniques similar to those used in the extraction of petroleum... 

Deutsch, W. j., W. j. Marhn, L. E. Early, and R. J. Serne. 1985. Methods of minimizing ground-water contamination fnm in situ leach uranium mining. Pacific Northwest Laboratory, Final Report NUREG/CR-3709. 

D. L. Whiting. "Groundwater Hydrology of Dump Leaching and In Situ Solution Mining,"... 

Uranium ore is typically mined or leached in situ. For the mined ore, the raw material is milled to produce a high surface area slurry, which is then treated with H2SO4. The sulfuric acid oxidizes the uranium to the soluble hexavalent state. The addition of base to the solution precipitates an oxide of uranium known as yellowcake , UsOs. A similar process is used for the in situ leaching of uranium ore except that the initial treatment is performed on bores with a slightly acidic and high oxygenated aqueous solution that is raised to the surface and allowed to go through an extraction process to remove the uranium. 

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