In an effort to improve the operator work environment, increase utilisation and meet increased drill production targets, Boliden's Aitik mine manager Erik Jänkänpää introduced an idea to trial electric autonomous blast hole drilling.

The trial ran through the month of March 2019 and was part of a three-year staged approach to autonomous drilling in Aitik that started in April 2017. The first part entailed tele-remote drilling. The results from that set the base for stage 2, a trial of single line autonomous. The third stage will evaluate the extent to which a whole pattern can be drilled with an electric autonomous drill.

The drill, an Epiroc Pit Viper 351, is currently running successfully and achieving 30 per cent increase in productivity compared to the manned equipment (190m day).

With the success of the project and positive feedback from the operators, a trial of autonomous drilling on two single passes (as opposed to multi-pass drilling) has now been performed. There will also be a test performed with the soon to be commissioned LTE network in Aitik.

The KPIs will be reviewed at a steering group meeting when a decision will be made whether to approve investment to upgrade the remaining fleet, which could start as early as October.

Shane Leighton, senior engineer Technology/Mine Automation, explained that the trial represents a world-first using an autonomous electric Pit Viper drill. Currently, diesel automated Pit Vipers are becoming the norm in other mining operations.

"There are quite a few mines in the world running diesel-powered automated drills; this is the first automated electric 351 Pit Viper. What we have learned from the trial in Aitik will support an upgrade to the 4 x 271 Pit Viper fleet in Kevitsa to an automated fleet that is scheduled to start in 2020," Leighton said.

The trial must achieve a number of KPIs covering three different areas safety, production and arctic weather conditions that will determine the decision to make a full investment. Currently, only single line drilling uses autonomous mode.

"Since we have never used this type of technology before, we wanted to be 100 per cent certain that we could be successful before deciding to upgrade our entire fleet of Pit Vipers. The trial addresses that," explained Leighton.

With regard to the safety, the same call-up procedures will apply when approaching the autonomous drill as for a manned drill. In addition, overview cameras mounted at various locations around the pit will allow the operator to gain a full overview of what is happening around the drill with four cameras located on the drills. A laser-based system for obstacle detection and a proximity detection solution are also new features designed to detect personnel; these will require staff to wear a tag that vibrates when entering the drill pattern.