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Tried, tested and true

Sandvik Mining and Rock Technology has launched an entirely new high-pressure DTH drill rig to complete its offering in the upper hole size range. Building on sound and proven engineering solutions and components, Leopard DI650i delivers solid productivity and advanced automation options for challenging rock conditions.

Text: Turkka KulmalaPhoto: Sandvik Mining and Rock TechnologyPublished: 1 November 2018

Down-the-hole (DTH) drilling has for decades been one of the dominating technologies in surface drilling applications. Sandvik Mining and Rock Technology is now complementing its offering of high-pressure DTH drill rigs with a totally new design, Leopard DI650i. “Our main focus was on surface mining operations, but the productivity and versatility of this machine also lend themselves very well to construction applications such as cement production,” says Jari Läntinen, product manager with Sandvik Mining and Rock Technology. “The fundamental design philosophy with Leopard DI650i was to opt for trusted main components, particularly the engine and the compressor, that have a proven long-term track record in the marketplace.” The prime mover is a 403-kilowatt Tier 3 CAT C15 diesel engine that drives a GHH RAND compressor to provide an airflow of 28.3 cubic metres per minute (1,000 cubic feet per minute) pressurized up to 30 bar (435 pounds per square inch). The maximum pressure rating gives excellent capability for high-pressure drilling with a 5-inch hammer. The dominant DTH hammer size is likely to be 6 inches, but 4- and 5-inch hammers are also possible. The pipe sizes range from 89 to 140 millimetres, depending on the size of the hammer. Over the 115- to 203-millimetre hole size range, the recommended optimum size is 165 millimetres. The rig weighs 30 tonnes (about 66,000 pounds) fitted out in a fully operational condition, topped with fuel and fluids and the selected set of drill piping and options on board.

Depending on the pipe size (89–140 millimetres, or 3.5–5 inches), the carousel can take a set of 8 + 1 pipes or a 4 + 1 set, giving a maximum hole depth of 53.6 or 29.6 metres, respectively (175 feet, 10 inches/97 feet, 1 inch). The rod handler system is entirely redesigned for improved efficiency. The standard rotary head option, HTRH6, has performed successfully on existing Sandvik DTH rigs and again reflects the philosophy of building on trusted main components. Leopard DI650i also offers a new heavy-duty option, MRH6, to match the demands in the upper range of the capacity area. The HD rotary head also makes a perfect match with the new series of Sandvik RH560 DTH hammers. The superior performance of Leopard DI650i does not merely rely on the powerful engine and compressor. It is the product of overall optimization of several factors, including the ergonomic iCAB cabin,

TECH SPECS

Drill hole diameter: 115–203 mm (165 mm optimum) (4.5–8″; 6.5″)
Drill pipe sizes: 89 mm (3.5″), 102 mm (4″), 114 mm (4.5″), 127 mm (5″) and 140 mm (5.5″)
Carousel capacity: 4 + 1 or 8 +1, depending on the pipe size
Maximum drilling depth: 53.6 m (175′ 10″)
DTH hammer sizes: 4″, 5″ and 6″
High-pressure compressor: 28.3 m3/min (1,000 cfm), max. 30 bar (435 psi)
Engine: 403 kW (Tier 3)
Operating weight: 30 t (approx. 66,000 lb)

excellent serviceability, mobility and fuel economy, as well as scalable automation packages. Thanks to exceptionally advanced serviceability and reliability, Leopard DI650i can offer up to 20 percent higher availability compared with conventional DTH rigs at a similar technology level. All daily servicing tasks are possible at ground level on both sides of the machine. Critical components and assemblies swing out, or can be pulled down or driven out, for easy access to all locations with regular servicing needs. The modular covers can be easily removed for maintenance work. All this helps the maintenance personnel to work productively without compromising on safety. Leopard DI650i uses the same silent and ergonomic iCAB cabin as Sandvik DXi top-hammer drill rigs; only the control panel layout is slightly different. The excellent visibility to the drilling area and a single integrated touch screen for all monitoring, diagnostics and mining automation displays are significant productivity factors for the rig operator. Leopard DI650i also stands out from the competition with its extra seat for a trainer or a maintenance technician. Fuel efficiency is a crucial parameter in terms of both productivity and environmental sustainability. Leopard DI650i saves fuel with an intelligent compressor control system that matches the compressor rpm with the required pressure and airflow. The hydraulics system additionally applies intelligent control technology to optimize the cooler fan speeds according to the weather and machine load conditions.

CUSTOMER CASE – Boliden Kevitsa

Boliden Kevitsa mine has produced nickel, copper, gold, platinum and palladium in northern Finland since 2012. The new Leopard DI650i was tested by Boliden’s drilling contractor E. Hartikainen Oy in the demanding arctic conditions in early 2018, in temperatures as low as -35˚C. The ground conditions at Kevitsa are challenging due to extremely hard fragmented rock. Leopard DI650i was taken to regular 24/7 production use after a brief set-up. Over two months, the unit accumulated more than 900 engine hours and more than 500 drilling hours and produced more than 15,000 drilled metres. Leopard DI650i delivered excellent availability throughout the test.

These improvements cut down Leopard DI650i’s fuel consumption by up to 15 percent compared with conventional DTH rigs. The flow-controlled drilling control system is yet another innovative option in Leopard DI650i. Whereas conventional pressure-controlled systems may suffer from fluctuations in the airflow, Leopard DI650i can keep the airflow constant and instead let the pressure level fluctuate to respond to more difficult ground conditions and increased backpressure. Advanced torque control functionalities prevent jamming and damage to pipe threads. The drill control system additionally includes an intelligent control sequence for hole finishing to discharge residual air in a controlled manner to prevent damaging blows without rock contact.

“The beauty of our new drilling control system is that you can still decide to use the traditional pressure control and save fuel when the ground conditions are not challenging,” Läntinen says. “But if there is significant backpressure, due to groundwater or collapsing holes, for example, you can maximize the flushing pressure and penetration rate by using the flow-controlled set-up.” Leopard DI650i joins Sandvik’s other latest drill rigs in its compatibility with the newest scalable automation solutions. The latest on-rig options include TIM3D navigation, My Sandvik fleet tracking system and full-cycle drilling automatics, which merge functionalities such as uncoupling, feed auto-aligning and feed auto-positioning into a single efficient sequence. These capabilities can be further upgraded with more advanced modules such as single-rig or fleet remote control systems. All in all, Leopard DI650i strikes a well-rounded balance between tried and tested engineering solutions and the latest advances in intelligent control systems and mine automation.