Latest in Sandvik rock drilling technology Dec 2020

Pekka Nieminen, Director Tunnelling, Sandvik
Sandvik Mining and Rock Technology reaffirms its leading position in the field of drill+blast rock excavation through the development and launch of advanced equipment, tools and consumables available to contractors throughout the world. Pekka Nieminen provides an update on the most recent developments.

The development of hardware for drill+blast excavation is more than the drilling rig itself. It must progress in parallel with developments in process consumables including the drifters or drills, the drill pits, bits and the drill rods. Sandvik continues its research and development of these vital units of equipment to continuously improve the productivity, safety and efficiency of the drill+blast method of rock excavation.

Top of the range DT1132i is fitted with advanced features for high drilling performance
Top of the range DT1132i is fitted with advanced features for high drilling performance

The Sandvik DT1132i jumbo is a large and highly productive underground drill rig. It is the latest addition to the extensive Sandvik range of underground drill rigs and is designed with a new high frequency rock drill, Sandvik RD535 and rock tools, for high speed drilling. It provides users with a heavy-duty solution for their underground drilling needs.

As with all Sandvik DTi jumbos, the latest additions to the product range have been developed with a modular design that makes them flexible and versatile. Suitable for fast face drilling or mechanized long-hole drilling and bolting, they are productive, reliable and effective. They use the latest developments in automated drilling solutions as made available by the Sandvik iSURE® management software and SICA intelligent control system.

The DT1132i itself is a three-boom, electro-hydraulic jumbo that has been purpose designed for fast and accurate rock drilling. The computer-controlled rig possesses both operator-controlled boom positioning and full-face automatic drilling functions. As well as incorporating some of the latest Sandvik developments in digital solutions, the rig is fitted with the new high frequency RD535 rock drill, robust booms and advanced drill string guides, making it a complete and high-speed drilling solution.

The essential premise behind the development of the DT1132i is to provide users with increased drilling performance and accuracy, which are made available through its adaptive drilling control for changing rock conditions. The rig design offers improved fleet standardization with high parts commonality that enables extended rig usage across different work sites. Among the many features the rig has is a new 3m telescopic TB160i boom which is optimized with a front wrist structure that provides 1m additional side coverage as standard and 4m side coverage with telescopic adjustment.

Ergonomic DT1132i cab with vibration dampened cabin, all round visibility acoustic windows
Ergonomic DT1132i cab with vibration dampened cabin, all round visibility acoustic windows

The rig design also maximizes operator safety and ergonomics. The ergonomic vibration-dampened cabin provides the operator with all round visibility, acoustic windows for low noise levels, a filtration system to minimize dust inside the cab in compliance with EU6/7 standard, and an open and spacious operator environment.

To further boost operator and rig efficiency, comprehensive diagnostics information is integrated and presented on one display. The display includes information on drilling diagnostics for boom control and positioning, a drilling control system, shank lubrication, together with carrier diagnostics for electric motors, hydraulic and water pumps, the transmission system, diesel engines, the brake system, jacks and cable reels.

Power, efficiency and reduced emissions

The DT1132i jumbo possesses a powerful transmission system with a Cummins B6.7, 168kW diesel engine of Stage V standard, which can be operated at up to 5,000m above sea level without any modifications. The new engine provides up to a 90% reduction in NOx emissions, when compared to Stage 3 engines, with more than 90% mass reduction for diesel particle matter. The rig utilizes a new carrier that uses more efficient hydraulic and water systems. The new TF535i feed for the rock drill provides increased feed force for high power drilling. Hydraulic hoses are of an increased diameter size while an improved hose reel structure gives longer service life for the hoses.

New RD535 drill provides high drilling speed without compromising hole quality
New RD535 drill provides high drilling speed without compromising hole quality

To deliver high levels of automated drilling, the DT1132i is available with some of the latest developments in automation including a SICA control system for intelligent torque control/feed percussion, with the My Sandvik software for monitoring and fleet management. To further improve the excavation process, remote access to the SICA and My Sandvik systems via WLAN (wireless local area network) can be used to allow web-based data transfer as well as online MWD (measurement-while-drilling) monitoring.

If purchased with the Gold standard features, the DT1132i comes with torque based semi-automated drilling, manual boom control and rod handling, all enabling drilling to a predefined depth with feed angle measurement and drill bit location measurement. Drill plan visualization and rig navigation are also included. In addition to these features, the rig is also available in a Platinum package, with automatic long hole drilling and fully automatic face drilling.

Drilling tool system and high speed bits

An underground drill rig is only as effective as the rock tools, rock drills and bits it uses. For face drilling, the DT1132i comes with the new Sandvik Alpha 360 drilling system for the RD535 rock drill. The system delivers features such as an optimized rod diameter with increased flushing hole size, increased flushing and higher penetration rates, as well as a new Sandvik Alpha 360 connection.

The new RD535 drill has maximized power transfer capabilities leading to a high drilling speed without compromising hole quality. It has a powerful patented percussion mechanism, as well as a patented stabilizer structure for increased reliability and longer tool life. These features, together with improved flushing and efficient cooling, provide uninterrupted high-speed drilling.

GT38 thread system for precision long-hole drilling
GT38 thread system for precision long-hole drilling
Alpha 360 thread system for the RD535 rock drill with optimized rod diameter and increased flushing hole size to deliver higher penetration rates
Alpha 360 thread system for the RD535 rock drill with optimized rod diameter and increased flushing hole size to deliver higher penetration rates

The DT1132i rigs fitted with RD535 rock drills, automated drilling features and new rock tools delivers up to 20% higher penetration, 25% more side coverage and 40% less exhaust particles.

The new Alpha 360 connector has led the way forward for the latest drilling tools systems from Sandvik. “High drilling accuracy is crucial to ensure that the tunnel gets the desired direction and profile. Straight and parallel holes also improve the advance per blast,” explained Robert Grandin, product manager, Underground Top Hammer, Sandvik Rock Tools.

The Alpha 360 is designed for 48mm to 51mm diameter drill holes for face drilling and bolting. A new larger bit thread permits increased drilling power and straighter holes to achieve a higher advance rate per blast. The short thread on the round rod increases resistance towards bending stresses, improved bit guidance and efficient energy transfer. The sturdy thread guided inside the bit skirt enables precision collaring including under complex rock formations and against uneven surfaces. “We always offer a full drill string from shank adapter to bit, designed for excellent reliability, performance and longevity,” said Grandin. When there is a requirement for precise pre-excavation grout hole drilling, the GT38 system is used to provide 50% less deviation and increased service life of the drill bit.

In addition to the drilling system, Sandvik has introduced its Speedy Bit as the fastest drill bit in the industry. Speedy Bit has a patented elevated front that breaks the rock in two levels and improves flushing flow, while large sludge grooves enable quick removal of large cuttings. As well as delivering 10% higher drilling speed, the innovative bit also delivers collaring accuracy and hole quality. By increasing the drilling speed by up to 10%, when compared to a standard bit with ballistic buttons, the Speedy Bit outperforms industry standard bits and can save users one hour per day for each drill rig.

“With increased drilling speed, customers can expect significant cost savings which can translate into more than US$100,000 per year per drill rig,” said Grandin. “Since drilling faster also reduces machine related costs per meter advanced for operators and maintenance, the Speedy Bit is an example of our aim to always maximize the output for our customer investments. Through more than 20 field trials drill speed increased by 9% on average, compared to bits with ballistic buttons and including several regrinds.” The Speedy Bit has been developed to boost productivity in the whole drilling process and is available in four dimensions: 43mm, 45mm, 48mm and 51mm.

Speedy Bit for higher penetration rates
Speedy Bit for higher penetration rates

The Speedy Bit, a design innovation for enhancing drilling operations, is also compatible and utilises one of Sandvik’s latest material developments, the new Sandvik PowerCarbide grades which are one of the most significant carbide innovations in rock drilling for decades. “Sandvik was the first company to manufacture rock tools with cemented carbide and we are continuously developing new and more advanced solutions. They are designed for customers who prioritize the longest possible service life on bits which has directly led to Sandvik introducing the new PowerCarbide grades,” said Grandin. “These are based on an improved knowledge about the wear of the drill bit in different types of rock.”

The GC80 gradient carbide has been developed for abrasive ground conditions with high silica levels with a new, unique method making it possible to produce buttons that are wear resistant on the outside, while the centre provides a toughness that extends the service life and grinding intervals. The SH70 self-hardening carbide, developed for hard, competent rock, is a grade with homogeneous properties throughout the material. SH70 is referred to as self-hardening due to its enhanced deformation hardening which enables it to take more wear when drilling as the surface hardness is continuously refilled, meaning that the hard top never wears off.

These developments in rock drilling technology are due to not only the Sandvik state of the art manufacturing processes and supply chains, but also to the investment Sandvik has made with regards to laboratories and continuous R&D. The extensive human resource capacity dedicated to cemented carbide development, for example, is more so than any other company in the industry. “For drill bits, controlling the whole chain, from our own tungsten mine to the production of bits, is an enabler for developing top class rock tools,” said Grandin. “With the most advanced range of carbides, we almost certainly have a product that is perfect for each customer’s conditions.”


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