History
Based on the US Patent database, the method history can be traced back to the beginning of the XX Century (1906). The most advanced BHM tool design was patented in 1926. With a few improvements, this design concept remains a base for the modern BHM tools and technologies. In the US, the major R&D were conducted by USBM in the 1970 and 80s. Borehole mining of Uranium in Kazakhstan remains the most advanced BHM project in the world.G. Abramov, Geotechnology - A Solution For Unconventional Uranium, IJSRED Volume 3 Issue 3 June 2020The process
# A borehole is drilled to a required depth; # A casing column is lowered down the hole. Since BHM takes place in an open hole, the casing shoe is located just above the upper border of the production interval (an ore body) leaving the rest open; # A BHM tool is lowered into the hole; # High-pressure water is pumped down and the tool is rotated and moved up and down.Description of a BHM tool
The tool consists of at least two concentric pipes which are forming two hydraulic channels - one for pumping down a high-pressure working agent (water) and second for delivering pregnant slurry back to the surface. A BHM tool typically consists of 3 major units: (1) a Bottom Head with an eductor ( waterjet pump) anAdvantages of BHM
The main advantages of the method include its low capital and operating cost, mobility, selectivity, ability to work in hazardous and dangerous conditions, low environmental impact and several more. The method is used in mining of such natural resources and industrial materials as: uranium, iron ore, quartz sand, fine gravel, coal, poly-metallic ores, phosphate, gold, diamonds, manganese, rare earths, phosphate, amber and several more. Borehole mining is also used in exploration, oil, gas and water stimulation, underground storage construction, environmental applications and a few more.References
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