Method and apparatus for slurry borehole mining

Patent · Tue Sep 07 00:00:00 EDT 1982

OSTI ID:6496624

Coakley, J E; Nolan, J J

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. Valves controlling the flow of fluid to the drill bit, the mining jet and the slurry discharge eductor pump are located within the inner conduit and a novel valve actuating means is disclosed which employs the pressure within the annular space between the conduits to convert the tool from the drilling to the mining mode. Surface mounted flow control valves and flowmeters in the fluid feed line and in the slurry discharge line control the volume of fluid entering and discharging from the tool. These valves may be controlled by instrumentation to balance the flows, adjusted to control the mining cavity pressure or to compensate for the influx of ground water.

• Assignee: Slurry Mining Engr Inc
• Patent Number(s): US 4348058
• OSTI ID: 6496624
• Resource Relation: Patent File Date: Filed date 1 Apr 1980; Other Information: PAT-APPL-136283
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
DRILLING EQUIPMENT
DESIGN
ORES
UNDERGROUND MINING
BOREHOLES
CONTROL EQUIPMENT
DRILL PIPES
HYDRAULICS
PUMPS
SLURRIES
VALVES
CAVITIES
DISPERSIONS
EQUIPMENT
FLOW REGULATORS
FLUID MECHANICS
MECHANICS
MINING
MIXTURES
PIPES
SUSPENSIONS
420206* - Engineering- Mining & Drilling Equipment & Facilities- (1980-1989)