Mining Publication: Technology News 460 - Prototype Borehole Miner Selectively Extracts Gold from Permafrost
ShareCompartir
Original creation date: July 1997
Placer deposits in permafrost often contain up to 15% cobbles and boulders. Because of erratic loading on the bit caused by elasticity and heterogeneity of the ice-and-gravel matrix, these deposits are extremely difficult to excavate. The approach taken in this research project was to mine only the ore-bearing portion of the deposit using a high-pressure water jet to thaw the gravels and a downhole hydraulic-lift-type pump to bring the ore to he surface as slurry. Full-scale jetting tests in frozen gravel were completed, and the data were used to design a jet excavator. The excavator will deliver a water flow of 890 L/min through a 15.7 mm diam nozzle at 6,900 kPa. The prototype slurry pump was designed to lift minus 15 cm gravels to the surface from a depth of 15 m.
Authors: GA Savanick, AL Miller
Technology News - July 1997
NIOSHTIC2 Number: 20000466
U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Technology News 460, 1997 Jul; :1-2
See Also
- Cableless Electronic Surveying Systems for Horizontal Holes
- Comparison of Rotary and In-Hole Motor Techniques for Drilling Horizontal Boreholes in Coal
- Correlation of Sonic Travel Time to the Uniaxial Compressive Strength of U.S. Coal Measure Rocks
- Demonstration of Remote Mine Seal Construction
- Detecting Strata Fracturing and Roof Failures from a Borehole Based Microseismic System
- Discharge Water Handling and Treatment: Problems and Solutions at a Large Pittsburgh Seam Coal Mine
- Effects of Stimulation Treatments on Coalbeds and Surrounding Strata: Evidence from Underground Observations
- Removing Methane (Degasification) from the Pocahontas No. 4 Coalbed in Southern West Virginia
- Transport of Total Tailings Paste Backfill: Results of Full-Scale Pipe Test Loop Pumping Tests
- Use of Vertical Boreholes for Assisting Ventilation of Longwall Gob Areas
- Content source: National Institute for Occupational Safety and Health, Mining Program