In conjunction with engineers Carleton Engineering Services, pumps manufacturer Hawk High Pressure Pumps has designed a new stope water jetter, which is traditionally used by the mining industry to move rock with water. The new design, which was first introduced in 2011, is gaining popularity in the South African market as it focuses on increasing the equipment’s efficiency and improving its ease of use and maintenance, says Hawk MD Gavin Pote.
Although the original concept of moving rock with high-pressure water is well established, the machines used to date have been very inefficient, he says. He explains that the volume of water used by these units is generally excessive and, considering that this water has to be continually pumped out of the mine, the costs involved are, thus, also unnecessarily high.
The original pumps, moreover, run continuously, resulting in high-energy consumption. In contrast, Pote points out that the new design only uses water as required, producing a reduction in water use of over 50% and, as it is only running intermittently, there is an additional reduction of electrical energy of up to 70%.
Pote adds that the new machine also uses a monocoque chassis casing which is opened using strong over-centre latches. This eliminates the need for tools, making the electrical and mechanical equipment entirely accessible and, thus, simplifying maintenance procedures. The sloped base of the units also allows for winching over rough terrain, while various other technical advancements make the machine highly robust.
Fewer components make assembly of the stope water jetter simpler, and all the chassis components are laser-cut and bent with computer numerically controlled technology to ensure the parts are standardised, he further highlights.
With water-powered drills introduced in the last few years to replace the traditional air-powered drills used to drill explosive holes at the face, Hawk, in conjunction with hydro solutions provider Hydro Power Systems, also designed a new type of water power pack. Drills configured with this pack have been trialled at various mine sites in South Africa for the past three years and Pote is confident that they are gaining momentum as an economically beneficial alternative to air-powered drills.
Pote explains that air systems have long been considered by those in the mining industry to be very inefficient, as air compressors consume large amounts of electricity. “Changing to a water-powered system, which is about four times more efficient, is, thus, a far better option,” he says.
Pote highlights that water-powered drills can drill a 1.2 m hole in 1.5 minutes, whereas their air-powered counterparts take eight to ten minutes to perform the same task.
He further notes that when using air-powered equipment mines incur significant maintenance costs in having to duct the air over many kilometres of pipework, as pipes are prone to leaking and constantly need replacement. In contrast, Hawk’s water-power packs can be positioned close to the operating area without requiring any plumbing.
“Older versions of the water-power packs were expensive and unreliable, and were set in fixed positions, with long hoses needed to transfer the water to remotely positioned drills. The longer the hose, the bigger the reduction in pressure at the drill itself. Our new version takes the pump directly to the workplace.
“Our machines offer savings on operating costs, as well as labour and energy costs. The overall cost of extracting ore is, thus, reduced and we are able to help mines increase their profits,” he concludes.