METHOD BOREHOLE CIL FROM DEEP LYING PLACERS AND MAN-MADE MINERAL FORMATIONS Russian patent published in 2014 - IPC E21B43/28 

FIELD: oil-and-gas industry.

SUBSTANCE: proposed CIL method comprises injection of activated leaching solution in producing bed via system of injection wells with subsequent extraction of gold. Said leaching solutions are injected via said system of injection wells in separate jets. First, hydrocarbonate-peroxide solution subjected to photo electrochemical processing is injected. Then after a pause, hydrochloric acid plus hydrogen peroxide subjected beforehand to UV radiation are injected. After detention of solution in producing bed till transition of the main portion of gold from mineral bulk into producing solution, perforated capsules with sorbent fitted with electrodes are placed into wells. Voltage is fed to said electrodes for direction diffusion of dissolved gold ions to sorbent and its sorption and extra leaching of gold remained in ore bed. Then sorbent saturated with gold is extracted to be recovered.

EFFECT: higher CIL efficiency.