Abstract: A method of drilling and mining a subterranean ore deposit with a tool string having a drill bit and a combined mining nozzle and eductor section with the fluid flow being controlled to each valve by self-activating valves. Controlling the operation of the downhole valves by the pressure of the fluid pumped into the tool string.An apparatus is provided for actuating down-hole flow control valves in a borehole mining tool to change the tool function from drilling to mining while still in the borehole. Single or double-acting power cylinders are employed as actuators with the system pump pressure applied to one side of the piston while a resilient spring and pneumatic pressure are applied to the other side of the piston. The spring and pneumatic pressure provide sufficient force to maintain the actuator in the drilling mode during the application of drilling pressure while mining system pressure overcomes these forces and actuates the flow control valves.
Abstract: A method and apparatus is provided for recovering deep subterranean ore deposits using conventional dual conduit pipe in the tool string. The drill cuttings and ore are returned to the surface by reverse circulation. A combination drilling and mining head is disclosed which permits the outer casing to be driven by the power swivel during both the drilling and mining operations. A hydraulic eductor pump located at the suction entrance to the inner conduit is used to raise drill cuttings to the surface; a separate slurry eductor pump within the inner conduit located only sufficiently below the slurry discharge of the tool to prevent cavitation at the jet is used to pump the ore slurry to the surface. Another embodiment of this invention employs both eductors to raise the drill cuttings and ore slurry to the surface.
Abstract: A method and apparatus is provided for actuating downhole flow control valves in a borehole mining tool to change the tool function from drilling to mining while still in the borehole. Self-activating actuators employing only system pump pressure control the flow of fluid to the drill bit, the mining jet, the discharge eductor or eductors and are located within the discharge conduit or in a compartment in the tool to change the function of the operative components. The valve actuator can actuate more than one valve simultaneously.