Sandvik Mining has announced a significant performance upgrade to its DL401-series underground top hammer production drills, designed to ensure continued and high drilling productivity, rock tool performance and process optimisation in a wide range of mine conditions, improving performance and profitability in underground mining.

Drilling productivity, rock tool performance and process optimisation
The upgrade covers Sandvik DL411, DL421 and DL431-series long-hole drills and enhances performance and profitability in several areas:

  • Accurate feed pressure control and feed controlled by rotation (torque drilling) – resulting in better sensing of hole conditions, energy transfer, penetration rate, rock tool service life and drilling accuracy, especially in soft rocks and downhole drilling
  • Zoom sensor system on DL431-series drills – ensuring accurate and fast positioning of boom to pivot point in fan drilling, improved operator performance, increased drilling accuracy and reduced ore dilution
  • Use of power extractor for uncoupling rods in automated drilling – easier and faster opening of joints reduces non-drilling time, increases drilling capacity and rock tool service life and reduces rock drill maintenance cost
  • Automatic flushing sequences in drilling cycles at preset intervals – ensuring improved hole stability, minimised interruptions, higher drilling capacity and improved rock tool service life
  • Independent percussion pressure control between drilling and back-hammering – enabling optimisation of pressure levels for each function separately, for maximum penetration rates, easy uncoupling of rods and improved tool service life
  • Automated rock drill stabiliser pressure control – automated pressure adjustment releases operator from manual work during fan drilling and improves operator performance (available with HL1560T rock drill on DL411/DL421)

The performance upgrade was released for new DL401-series drills in January. Aftermarket kits for units already in the field will be available at the same time.

According to Sandvik Mining’s product manager for underground top hammer production drills, Jukka Naapuri, the automation and intelligence introduced in DL401-series production drills will help Sandvik customers achieve more consistent longhole drilling productivity in a wide range of mine conditions, regardless of operator experience, and improved process optimisation through better drilling accuracy, better ore recovery and minimised ore dilution.

"At the same time, we have taken the opportunity to introduce a number of features designed to minimise interruptions and delays in the drilling process, reducing non-productive time, helping deliver more metres of rock drilled per shift and to improve tool economy further," Naapuri said.

"In addition, the ability to achieve more accurate fan drilling with the new zoom sensor system on the DL431 means improved ore recovery, reduced dilution and fewer oversized boulders in the stopes to be processed."

Naapuri said that the performance of DL401-series drills had also been optimised for automated and tele remote drilling, allowing full-fan remote operation of one or more machines to be carried out by a single operator.

"We also offer the industry’s widest range of production drills, providing mine operators with versatile rigs that closely match the production requirements of different mining methods, and all built to the highest quality standards, ensuring robust and durable drills able to provide years of reliable production."

Sandvik DL401-series top hammer production drills

Sandvik DL401-series drills are fully mechanised and highly versatile electrohydraulic longhole drills designed for large-scale underground mining in 4m by 4m or larger cross-sections. The DL401-series drills are mounted on four-wheel drive frame-steered and diesel powered undercarriages and equipped with Sandvik HL710 or HL1560T hydraulic rock drills, drilling modules, longhole booms and FOPS/ROPS certified operator stations for maximum performance, safety, reliability and total drilling economy. The 360˚ boom rotation and wide swing/tilt angles make the units suitable for longhole drilling in most mining methods and various drilling applications.

Instrumentation and data drilling with various automation options enable maximum performance with the highest levels of drilling accuracy. The on-board CAN-based technology allows the operator to set the unit for any rock conditions, as well as allowing easy upgrades to various levels of automation. Drilling and tramming is carried out from the ROPS/FOPS-certified operator’s platform, while drilling from a remote position next to the machine is also available.

All drills also incorporate high levels of operator safety and ergonomics, including ergonomically designed operator compartments, with easy access and exit, incorporating safe three-point contact and anti-slip surfaces, hand rails and steps in a high-visibility color, additional lights for safe stepping and a boot washer (on cabin models).

Most daily maintenance can be carried out from ground level, while all main components have easy access through covers that can be quickly and easily opened and closed including the ability to open and close the covers easily.