Abstract: A permeable region adjacent a well bore used in an acidic in situ leaching system can be repaired by introducing a non-acidic liquid for displacing acidic leach liquid from the permeable region, introducing into the well bore a basic composition including a polymeric material that gels under acidic conditions, and applying sufficient pressure to the well bore to displace at least a portion of the basic composition and polymeric material from the well bore into the permeable region adjacent the well bore. Liquid flow in the well bore is then discontinued for a sufficient time for acid remaining in the subterranean formation adjacent the well bore to contact such polymeric material and cause gelation of the polymeric material in the permeable region. The introduction of acidic leach liquid can then continue.

Abstract: An improved in-situ ore body chemical-mining system and method are disclosed, whereby it is practicable to mine an ore body of substantially horizontally extended configuration which would otherwise be uneconomical because of adverse overhead or overburden conditions. Beginning adjacent the distal ends of two or more generally horizontally drilled and substantially parallel bore holes which are drilled into the ore body from an elevation substantially similar to that of the ore body, a combination of permeabilizing and mining processes are applied to the body of ore circumjacent the horizontal penetration. The permeabilizing and mining processes are retrogressively applied to successive blocks of the ore body retreating by stages from the distal region of the penetration towards the entry region thereof.

Abstract: There is disclosed an improved system method for in situ extraction of mineral values from subterranean deposits of ores of the oxide; carbonate; sulphide, or other type ores which contain sought-for metal values and which evolve gas when reacted with suitable chemicals in solution and/or gaseous form. The invention is particularly applicable to in situ mining of the previously found types of copper, nickel, manganese, etc. oxide, carbonate, and sulphide ores and the like; and especially features conservation of energy which otherwise would be wasted.