In a recent interview, IM again spoke to Donovan Waller, Group Head of Technology Development, on the group’s latest progress with a range of important projects with a range of key mining machinery and technology OEMs. While these are difficult times for Anglo American and the whole industry, the learnings from these underground cutting and rapid mine development projects are vital to the future of underground operations in an era of deeper mines, lack of skilled workforces and an ever increasing focus on removing people from active mining areas.
Based on an Australian patent for oscillating-disc cutting, Joy Global developed a machine prototype in South Africa going back several years. After extensive cutting on surface in UG2 and Merensky orebodies, the proof-of-concept underground trial has been completed at the Bathopele mine of Anglo American Platinum. To cut a rectangular opening, the machine used tungsten carbide inserts in a oscillated cutting disc arrangement and in an undercutting mode. It also successfully demonstrated use of a vacuum system for collection, transport, and material handling directly onto the mine conveyor belt system. “The experience and knowledge gained during this trial provided invaluable input and knowhow for the future hard-rock cutting machine design. The collaborative work on a cutting system is continuing with Joy Global.”
Another technology development partnership has been formed with Atlas Copco to create a rapid mine development system (RMDS). On this concept, the TBM-style disc cutters are mounted on a horizontally rotating cutter head that protrudes from a road-header type of mining machine. In this arrangement, the RMDS shows the distinctive features of a TBM, but excavates a rectangular-shaped tunnel, which is important for roof stability purposes in South African platinum mines, as well as providing the flat floor needed by mine vehicles. The ore removal system is mechanical, via two internally integrated conveyors. The RMDS is now undergoing a functional and operational test program.
On reef mining, building on the solid knowledge base gained during the years of trials of the ARM1100, Sandvik and Anglo American joined forces to work on the next stage of the undercutting narrow reef miner’s development. The trial of MN220 started at Anglo American Platinum’s Bathopele mine in 2013, and after the successful achievement of the proof-of-concept phase’s KPIs, the development work is now concentrated in two directions: optimisation of the cutter arrangement as well as the installation and testing of the pneumatic ore removal and transport system.
Finally, leading from an early idea to extract ore by drilling narrow orebodies, Anglo American partnered with Atlas Copco to develop a platinum reef drilling system called Slot Borer. The cutting system is based on proven raise-boring technology and deploys the TBM-style steel discs in a compression cutting mode. The system consists of a cutting/drilling machine and a pneumatic conveying system to remove the cuttings and transport them to the conveyor belt. Upon successful completion of functional tests at the factory and the mine site in Sweden, the Slot Borer is expected to be subjected to proof-of-concept trials in South Africa in the near future.