Shotcrete spraying simulator training cuts waste
Swedish company tests waters in Canada
Most operators of shotcrete spraying equipment are trained onsite in a noisy, dusty production environment. The experienced operator has control of the joysticks and has to scream at the trainee to be heard. “It’s not conducive to training,” according to Adrian Hedstrom, international account manager for Edvirt, a Swedish company that has developed a 3D simulator for training shotcrete sprayers.
Hedstrom spent a month in Sudbury – camped out at NORCAT – to introduce its shotcrete spraying simulator to the Canadian mining industry.
The need for a better way to train shotcrete sprayers was raised in 2008-2009 when contractors and mining companies in Sweden realized that skill levels and spraying quality varied from operator to operator.
“They wanted to be able to train more like the airline industry, which uses simulators,” said Hedstrom. A prototype developed through a research program at Chalmers University of Technology in Gothenburg led to the founding of Edvirt in 2013.
The portable simulator, which includes a computer, a projector, a screen and a joystick control unit, is currently in use in Australia, Peru and several European countries, including Sweden, Germany and Switzerland.
Training in Canada could be offered in partnership with NORCAT and/or equipment manufacturers such as MacLean Engineering.
Studies of shotcrete spraying quality supplied by Edvirt estimate wastage of up to 39 per cent, including 20 per cent of the material wasted as a result of overspraying, 16 per cent lost through rebound and three per cent from fallout. By contrast, highly skilled operators waste an average of only 18 per cent of material – 10 per cent due to overspraying, seven per cent through rebound and one per cent from fallout.
Hedstrom offers the example of Swedish miner LKAB, which uses 200,000 cubic metres of shotcrete every year costing $60 million. Unnecessary usage – “money on the floor,” according to Hedstrom – would add up to $9 million based on 15 per cent waste and potentially much more depending on the skill level of the operators.
“Many times, the contractor will blame the problem on the equipment or the material they’re using, but you can use the same equipment and the same material and get different results, so this is what we want to prevent,” said Hedstrom.
“With the simulator, we can make sure that the operator gets the intensive training it takes to get the right technique.”
Operators learn through visual feedback how many passes to make to achieve the proper thickness and control the rebound by positioning the nozzle at the correct angle. They also learn the different techniques for applying shotcrete to different surface areas.
The trainee’s skill level is calculated before and after the training to measure the improvement.
Shotcrete is widely used in tunneling and in the Swedish mining industry because it provides improved ground support for workers. In Canada, “it’s still relatively new,” said Hedstrom. “Most mines only use it to support soft ground. In Sudbury, some mines don’t use it at all. Others spray every day.”