About Underground Borehole Mining (UBHM)

In the UBHM process, a conventional drill rig bores a hole through the overburden to the mineralized horizon. Once the mineralized horizon is reached, the borehole is cased and sealed and the overburden drill rig is exchanged for a specialized mining rig with customized equipment, including a “Fixed Shrouded Jet Miner”. The jet miner is lowered through the casing to the exposed face of the mineralized material, and uses pressurized water supplied by surface pumps to excavate material from the ore body in a 360-degree arc around the borehole.

An internal airline within the mining pipe provides a continuous supply of air to depressurize the return pipe and create a vacuum to lift a slurry of mineralized material through the drill pipe to the surface.

Once a borehole has been completely mined, the remaining cavity will be filled with specialized cement slurry. The borehole is then backfilled and the top of the casing is plugged with bentonite and cement before final completion with a soil cap.

The Scoping Study envisages 2 overburden drill rigs and 3 borehole-mining rigs to produce approximately 2mlbs of U₃0₈ per year. Each borehole will yield approximately 3,500t of ore, containing 9,800lb of U₃0₈, though this will vary with the grade thickness of the mineralized zone in different areas.

The precision of UBHM mining provides Black Range the ability to target individual resource deposits several hundred feet underground with relatively minimal environmental impact. The mobility of drill rigs allows the Company greater flexibility in targeting resource bodies based on grade and how they can be most cost-effectively developed according to the mine plan.