Water powered drilling is proving its worth in an iron ore mine in Sweden

The mining industry is continually looking for new drilling solutions that enable them to mine deeper, faster and more narrowly while at the same time, be more environmentally friendly and reduce costs. 

Increasingly underground mines are reaching depths that current mining methods can't manage cost-efficiently. 
Deeper, leaner ores means larger scale drilling and mining needs to be more precise and safer. 

With these factors in mind, Wassara have developed and implemented water-powered drilling equipment.

The Wassara production drilling system for blast-hole drilling consists of hammers, bits, check valves, drill tubes, high-pressure swivels, high-pressure hoses and electric high-pressure water pumps. 

Today, the water-powered technology is widely used around the world, particularly in the areas mining, exploration, dam rehabilitation and ground engineering. 

Swedish mining company LKAB have been able to upscale their production by 800%, by using Wassara's DTH hammer that allows them to drill long straight holes at a minimised energy cost.

LKAB have currently drilled more than 18 000000 metres with the system and more mines are now beginning to discover the benefits of the Wassara system.

"LKAB has been using this technology for their blast holes for over 20 years and has drilled more than 18 million meters, all well documented. We have completed it with more sizes and models that are used in ground engineering, dam rehabilitation and exploration drilling," Kent Boström, communications manager at LKAB Wassara said. 

Wassara implemented the world-patented DTH hammer, which uses high pressure water to power it. 

With water giving high frequency and high energy per blow, using water as power transmission makes the hammer suitable for drilling in most applications and optimal for use in areas where it's difficult to implement other technologies.

 Wassara water-powered system drills very long, straight holes, which results in well-fragmented ore after blasting. 

When the water leaves the hammer it has enough velocity to bring the cuttings and debris to the surface, leaving a clean hole. 

Recognising that increasing the slice height between sublevels would reduce costs as long as dilution could be carefully controlled, the Mining R&D team studied the options for drilling longer holes.

The use of water drilling creates smooth, straight holes with minimum deviation, borehole quality, high productivity and little impact on the formation. 

Whilst using the water powered to scale up ore iron production at LKAB's Kiruna mine, the length of blast holes was increased from 28 to 56 meters. This gives 28 meters between the levels and drifts from the current 12 meters, reducing the number of development drifts needed by 70%. 

The outcome from each blast has risen from 1,200 tonnes to 10,000, or 8.3 times more. 

The bore holes are up to 56 meters, depending on the shape of the ore body and the rate of penetration is up to 1.2 meters per minute with 115 mm drill bits. 

Less deviation is also important to maintain good fragmentation of the ore when blasting. Wassara meets the maximum allowed bore hole deviation in LKAB of 1.5%. 

The systems also have a number of environmental benefits. The hammer runs on clean water without any oil additives, which results in a working environment free of dust particles and oil mist. 

Since a high-pressure water pump is much more efficient than an air compressor the energy consumption is roughly 25% of a comparable air drilling system.

An additional benefit of this is a reduction of CO2 emissions and an improved work environment with less drill dust and no oil mist, which directly addresses the drill safety issue of superheated air.