Blowing boreholes up more safely
Finnish mining and tunnelling technology company Normet is revolutionising underground explosives charging with a novel system that improves operator safety underground. The system has a remote controlled robotic arm that places the initiating system into a borehole and uses an emulsion kit to dispense emulsion. This allows the operator to remain in a supported tunnel area, and far from danger. Earth’s available ore deposits are being used up, forcing mining companies to dig deeper to extract the ore they need. However, the further underground they go, the higher the risk of rockfalls and rock burst accidents. According to the Normet website, there is only one tangible way to improve operator safety, and that is by removing “the operator from the high exposure danger zone, the unsupported area of the tunnel.” That is precisely what its Charmec Revo® technology developed with support from the EU-funded IMOCO4.E project does. Developed for tunnels between 4 x 4 m and 6 x 6 m, the system can be used in most underground mining tunnels. The charging manipulator consists of an agile servo-robotic arm built to meet the needs of underground mining.
How it works
The system enables drilled borehole maps from drill digs to be uploaded in order to locate the boreholes in the face wall. If no such information is available, a machine vision system helps operators locate the drilled boreholes. Once a borehole is found, the charging hose delivery system takes care of the priming unit and explosive delivery to the borehole. The system can also recognise plastic lifter pipes and help in their utilisation. Collision avoidance is made possible using ultrasound sensors to slow down and stop the robotic arm before it comes into contact with a tunnel wall or other obstacle. Additional safety sensors pick up when the operator enters the working area and stop boom movement. According to the Normet website, the Charmec Revo® system can be adapted “to use any commercially available wired, semi-wireless or wireless initiating systems. The priming unit can be handled manually or by using magazines provided by explosives suppliers.” Additionally, the initiating system magazine is placed on a platform next to the charging arm, making the priming unit’s unique pick-and-deliver method possible. The Charmec Revo® system can be used with all commercial bulk emulsion systems. “We have extensively tested the Charmec Revo technology in underground mining and it has demonstrated its ability to improve operational safety while retaining similar productivity. Ease of use and low learning curve ensure effortless implementation of this technology,” remarks Normet Product Line Director of Explosives Charging Anssi Mykkänen in a news item posted on ‘International Mining’. The IMOCO4.E (Intelligent Motion Control under Industry 4.E) project ends in August 2024. For more information, please see: IMOCO4.E project website
Keywords
IMOCO4.E, mining, underground, charging, explosive, safety, borehole, tunnel
