Global energy demand was expected to increase by 40% within the next 20 years, mining equipment manufacturer Sandvik regional product line manager David Hickson said at an event hosted by Sandvik in Johanneburg last month.

He pointed out that this also pertained to continued growth in coal markets and the development of new coal mines, as coal-fired power stations in Africa remained the primary source of energy generation.

“There is a need to increase current energy production in a more effective and safer manner. Sandvik saw a gap in the market with regard to energy demand and developed the MC470 double pass miner that has the capabilities to use current unproductive times of the cutting cycle to allow for increased production rates,” Hickson said.

He added that the health and safety functionality of the machine was an improvement to its predecessor, the single pass miner.

The MC470 double pass miner comes in various ranges, including the MC35, which is low-seam; the MC400, which is midseam to high seam; and the MC470, which is high seam.

The MC470, which is radio remote controlled, is a smaller machine that weighs 125 t and is a high-powered 3.3 kV bidirectional miner, he said.

Hickson added that its features included a rugged design, low ground pressure, and a powerful, on-board dust-extraction system, with improved spraying systems for better dust control.

He pointed out that health and safety aspects of the machine included improved fan design, reduced noise reduction when the scrubbers were in operation, and scrubber monitoring.

“The primary method of ignition prevention of the incentive temperature potential (ITP) system is through ventilating the cutting zone. This is achieved by specifically designed and approved arrangements of hollow cone sprays, designed to direct fresh ventilation air into the top of the cutting zone to expel methane from the cut into the area below the cutting jib,” Hickson explained.

He further noted that this area, in turn, was ventilated by further sprays to ensure the rapid dilution and removal from the face of the heading in conjunction with the auxiliary ventilation system, providing the fresh air over the top of the machine.

“Dust control and improved fan design reduce noise by reducing the speed of the fan motor and increasing velocity by 25%. “The computational fluid dynamic model sucks in dirty air from the front of the miner, dilutes it and pushes fresh air out of the back of scrubber system,” he said.

He cited that the airflow monitoring system was a feature in the software that ensured the required airflow for scrubbing is adequately supplied, with a differential pressure sensor used for monitoring.

“The sensor compares two measuring points in the scrubber box. The monitoring limits are fixed according to the local requirements and stored in the software.
When the airflow is outside the specified limit, the cutter motor shuts down after 30 seconds,” he concluded.