February 16, 2017
Antwerp, Belgium, February 16, 2017: When Coal Augering Services, a high-wall mining contractor, needed to decrease the oxygen level and stop any risk of possible gas blasts at the BHP Millennium coal mine, they relied on Atlas Copco Rental to provide a total solution.
The Millennium Mine is an open-cut mine located 100 miles (160 kilometers) south-west of Mackay, Australia, which produces coking and low to mid-volatile pulverized coal injection (PCI) for export markets.
Coal Augering Services has been contracted to drill some 280 holes in the lower open pit seam in order to recover an extra 25 % of coal (or approximately 75,000 tons). Holes vary in depth from 35 to 75 meters and have a diameter of 2 meters.
During this operation there is a high risk of explosive gases being present so solution needed to be worked out. To prevent explosions Coal Augering services started by using a diesel driven Inert Gas Generator (IGG) where the air is burned using diesel in order to decrease the oxygen level to less than 12 % at 15 meters depth. They however rapidly converted to a Nitrogen generator from Atlas Copco Rental Australia for that purpose.
Thanks to our mobile NGM 200 nitrogen generator, delivering 96% N2 purity at 9 bar, combined to an XAVS 850 air compressor, it was possible to achieve the required inert levels at 12 meters for both 35 and 75 meter depth holes, thus avoiding all risks of explosions.
Along with that main challenge, there were several other aspects that we needed to account for.
Tim Vaughan, Atlas Copco Rental Australia - Account manager, Queensland & PNG explains: “After minor teething issues, the customer has signed a long term contract and is happily converted from inert gas generator to a safer and even more reliable Nitrogen solution.”