Horizontal raise boring technology to double mining productivity in kimberlite. Master Drilling’s Horizontal Raise Boring (HRB) technology is ready for international roll-out after the successful pilot test at the Cullinan mine. HRB can replace conventional drill-and-blast mining and increase mining productivity thanks to its continuous process of rock boring. In addition it offers significant safety benefits. The company says “projects with less safe access, such as deeper mining operations and higher stress zones, are more likely to pass feasibility tests thanks to the safety improvements that HRB brings.”
The latest version of the Master Drilling HRB was officially unveiled at the Investing in Africa Mining Indaba 2017, held in Cape Town.
Master Drilling is a South African based JSE-listed drilling solutions provider with over 160 drills across 17 countries. HRB is an entirely new rock boring solution and can be offered to Master Drillings’ existing client base of multinational mining companies and new clients in mining and civil construction. The technology is expected to offer support to Master Drilling revenue growth over the medium to long term, and thereby provide further income diversification.
“HRB is a locally developed, world-first technology that promises to change the very fundamentals of the global mining industry,” said Danie Pretorius, CEO of Master Drilling. “The feedback from our multinational business partners from Southern Africa and Latin America on visits to the actual technology has been highly encouraging.”
HRB will provide the mining industry with an excavation and construction tunnelling tool for the mechanical excavation of a tunnel between two existing access points, very similar to the standard form of raise boring. The steady progress of the reamer is able to excavate an average 6 m/d, compared to 2 m in conventional drill-and-blast cycles, Master Drilling reports.
The technology offers the much-needed mechanisation to reduce the number of workers who are exposed to dangerous underground conditions. The benefits extend across the project-chain and include amongst others:
- No need to use explosives
- No blast effected damage inflicted to the tunnel sidewalls
- The structure of the tunnel is stronger due to the circular profile of the tunnel
- Reduced rock support costs
- Improved tunnel construction accuracy
- Lower excavation costs
- Continuous operations not effected by blast re-entry
- Greater remote operated possibilities
- In certain locations it is impossible to assemble a tunnel boring machine (TBM) due to its length and size. In these locations the plant for raise boring is smaller and easier to transport.
The pilot project at the Cullinan mine of Petra Diamonds involved boring and excavating a 180 m horizontal tunnel with 4.5 m diameter through the kimberlite ore. The method entails first drilling a smaller pilot hole through the kimberlite, which was challenging as no water can be used for flushing. The pilot hole also needed to be near perfectly straight. For these reasons Master Drilling pioneered using vacuum air suction and laser assisted directional steering in collaboration with a US-based company, which is typically used in civil construction.
“Tunnel Cutting Technology seems to be the next logical step in underground mine development,” said Ben Swarts, Group Manager, Mining Projects of Petra Diamonds. “This technology brings with it additional benefits such as improved excavation integrity and safety, better advance rates and possible downstream financial benefits. The HRB is one of the very few options currently in operation. We are optimistic about the technology and in progress to finalise a commercial agreement to continue the use of the HRB within Petra Diamonds.”
Master Drilling’s business model is that of a contractor who designs and manufactures its own drilling equipment to provide complete drilling service solutions. It does not sell any of it’s machines. Master Drilling recorded revenue of $58.3 million in the six months ended June 2016, and net profit of $9.6million for the period and market capitalisation of R2.5 billion, with a $209 million order book excluding HRB.
“Master Drilling is about selling a solution and not a product. Our technologies are the result of identifying and responding to needs in the market – ahead of the curve,” said Pretorius.
Over the years Master Drilling has developed new technologies including the Remotely Operated Shaft Inspection Unit (ROSI), amongst others. Currently Master Drilling is developing the Blind Shaft Boring System (BSBS), a mechanised system for boring a vertical shaft to a depth of 2,000 m with finished diameters ranging from 10 m to 13 m. No underground access is required for the BSBS to start boring operations as a shaft sinking method.