Mechanical engineer Rod Pickering spent 20 years at the Chamber of Mines Research Organisation (Comro) running the stoping technology laboratory, the part of the now-defunct Comro that focused on hard rock, narrow-reef mining.

After leaving Comro in 1996, he spent another 18 years running his own business and again focused on the adoption of better mining methods in that narrow-reef space.

Now, as chairperson of the Centre for Mechanised Mining Systems steering committee, Pickering’s message is crystal clear: South Africa’s narrow-reef mining has to move to the next level, or the country will end up with closed mines on its hands.

The function of the ten-year-old Centre for Mechanised Mining Systems, located at the University of the Witwatersrand (Wits), is to identify appropriate technology applications, understand the people factors and adopt a systems approach to mining mechanisation and automation in some of the country’s deepest, darkest and most dangerous precious metals operations.

The latest breakthrough is a combination of mechanised equipment and selected blast mining (SBM), which provides the best of both worlds.

Pickering’s comments dovetail with those of veteran research commentator Dr R E (Robbie) Robinson, who has called for the introduction of SBM in South Africa’s narrow-reef stopes as a way of boosting the struggling sector.

The mechanisation introduces efficiency and eliminates the need for people in the vulnerable areas and SBM eliminates dilution and boosts metal recovery.

Mechanised mining methods have gone on apace outside of the hard rock, narrow-reef scenario.

Opencast mining, room-and-pillar mining and block-cave mining have, the world over, all mechanised successfully, leaving South Africa’s generally tabular-orebodied mines with an urgent need for a higher productivity solution.

Gold has been a serious laggard, as the deciding factor when it comes to room-and-pillar mining, which is what most practitioners have adopted, is the angle of the dip being not more than 100, whereas it is a substantially steeper 230 in many West Wits and Carletonville gold mines.

In chrome and platinum mining, where the dip is generally not more than 100, 30-million tons a year are being mined using mechanised low-profile room-and-pillar mining method in narrow-reef orebodies.

Original-equipment manufacturers (OEM) have come to the low-profile party and the number of pieces of equipment acquired by mining companies has justified the OEM investment into equipment designed for narrow stopes.

However, the shortage of artisans to maintain the equipment does present difficulties.

“We’ve had a shortage of those kinds of hands-on skills for many years,” Pickering tells Mining Weekly Online.

To overcome the shortage, companies like Sandvik have established major apprenticeship training programmes.

There is also a shortage of management with an understanding of this mechanised method of mining and most graduates are being skilled up to do conventional mining.

To remedy that, the Centre for Mechanised Mining at Wits has put considerable effort into course development on trackless mechanised mining, rock cutting and materials handling, and the university itself now has an MSc Honours degree in mechanised mining.

The most recent course on trackless mechanised mining attracted 40 people, an indication that the industry is recognising the shortfall and that the university has something to offer.

The enrolment of particularly black students into mining has been substantial in recent years.

However, because of the lack of mining uptake by students in the 1980s and 1990s, there is a middle-management gap and a shortage of mentoring, which the centre is also addressing.

Source: - See full article