Leaching in Place

In-place leaching can only be applied in geologically favorable cases, that is where the rock is porous to allow the percolation of the leaching... 

R. L. Braun, A. E. Lewis, and M. E. Wadsworth, In-Place Leaching of Primary Sulfide Ores ... 

Braun, R.L., Lewis, A.E., and Wadsworth, M.E., In-place leaching of primary sulfide ores, in Solution Mining Symposium, Apian, F.F. (ed.), AIME, New York, 1974. 

In unsteady-state leaching a common method used in the mineral industries is in-place leaching, where the solvent is allowed to percolate through the actual ore body. In other cases the leach liquor is pumped over a pile of crushed ore and collected at the ground level as it drains from the heap. Copper is leached by sulfuric acid solutions from sulfide ores in this manner. 

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. 

Hydrometallurigcal Processes. In hydrometaHurgical processes, metal values and by-products are recovered from aqueous solution by chemical or electrolytic processes. Values are solubilized by treating waste, ore, or concentrates. Leaching of copper ores in place by rain or natural streams and the subsequent recovery of copper from mnoff mine water as impure cement copper have been practiced since Roman times. Most hydrometaHurgical treatments have been appHed to ores or overburden in which the copper was present as oxide, mixed oxide—sulfide, or native copper. PyrometaHurgical and hydrometaHurgical processes are compared in Reference 34. 

Percolation In addition to being applied to ores and rock in place and by the simple technique of heap leaching (usually on verv large scale see Wadsworth, loc. cit.) percolation is carried out in batcJi tanks and in continuous or dump extractors (usually on smaller scale). 

MACRO Macroencapsulation Macroencapsulation is the application of a surface coating material to seal hazardous constituents in place and prevent them from leaching or escaping... 

The polymer has the function to retain the indicator in place so that no leaching into e.g. aqueous sample solution occurs. This can be achieved by covalently immobilizing the dye to the matrix but also by simply dissolving a hydrophobic and water-insoluble dye in a hydrophobic polymer. 

Soil washing involves the leaching of contaminants by the flushing of water through the contaminated soil. Soil washing can be accomplished either in place or aboveground as discussed below. 

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