Mechanised mining in the spotlight

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[miningmx.com] — CHIEF inspector of mines Thabo Gazi has denied speculation that the Department of Mineral Resources (DMR) is about to insist on major design changes to mechanised mining operations on platinum mines.

The speculation has emerged from platinum industry sources, despite the apparently cordial outcome of the meeting between Minister of Mines Susan Shabangu and 15 platinum company CEOs in Pretoria on Thursday.

In a statement released on Friday, Shabangu said: “We have agreed to look, for example, at how rock engineers can work together with government’s mine inspectors and with trade unions to share information and share best practice models.’

The meeting followed the death of five mineworkers last week in a fall of ground at Aquarius Platinum’s Marikana mine near Rustenburg. The affected shaft is still closed.

Nine mineworkers were killed in a similar incident last year at Impala Platinum’s (Implats’) No 14 shaft near Rustenburg.

Following that accident, Implats management decided to reduce the panel width in its mechanised operations from 14m to 6m. The panel width is effectively the unsupported span of rock between pillars in the mechanised mining operations.

Industry sources were concerned that the DMR may be about to insist that all mechanised platinum mining operations adopt this standard, despite major differences between the various mines in terms of depth and rock type.

Asked to comment on this, Gazi told Miningmx: “I don’t know about that. That was not part of the discussions, which did include the issue of mine design but did not get into any specifics.

“It was discussed that the recent falls of ground in platinum mines were related to engineering issues and there was a need for more information sharing in terms of mine design.

“We engaged at the level that mines must be designed with the best knowledge and technology available. There were no prescriptive measures on what bord and pillar sizes should be.’

In a research note released on Thursday, JP Morgan Cazenove analyst Steve Shepherd said: “In our view, there is a risk that the DMR is about to intervene in the area of systematic support designs for mechanised platinum mining.

“This is a possible concern, since from an engineering perspective these systems need to be considered on a site specific basis.

“In our experience, when government mining engineers become involved in setting support standards for mines in reaction to “big accidents’, there’s a risk that political considerations might outweigh engineering considerations.

“In the context of the types of support designs applied in bord and pillar mechanised mining (and other methods for that matter) “one size definitely does not fit all’.’

According to Shepherd, “a new, more stringent, blanket support ruling would almost certainly lead to reduced extraction rates, lower efficiency, lower production and higher costs at affected mines.’

Shepherd pointed out Implats lost about 20% of its production from bord and pillar mechanised stopes following the reduction in panel width.

He said Aquarius Platinum appeared to be the company which was the most exposed to such changes, because it derived at least 85% of its South African production from mechanised bord and pillar mining.

Implats would not be affected because of the changes it had already implemented.

Anglo Platinum would be marginally affected because it gets less than 20% of its production from bord and pillar mining, including its share of the Kroondal, Marikana and Mototolo joint ventures.

Shepherd said the impact on Eastern Platinum and Anooraq Resources would be negligible and Northam Platinum would also be little affected, at least until the new Booysendal mine came on stream.

He added Lonmin should not be affected, because it used a totally different type of mechanised mining at its Hossy Shaft to bord and pillar mining.

Shepherd said: “Let’s be very clear – it would be quite wrong to assume that other miners would lose 20% of their mechanised output like Impala did.

“Each mine has its own bespoke support designs modelled around its particular and unique parameters.

“Aquarius’ Marikana mine, we understand, adopted 10m panel lengths for example, not the 14m standard that Impala had applied prior to its accident.

“This said, we are aware that the DMR is examining mechanised support standards across the industry and that this may lead to enforced standard changes that we think will reduce the efficiency and output of mechanised bord and pillar stopes.

“It is not possible at this stage to calculate the value impact that any support standard changes may have without specific disclosure from any affected miner.’

The assessment by John Meyer, analyst at UK institution Fairfax, was that “platinum and gold mines are likely to see rising costs, capital requirements and potentially lower production levels to accommodate more stringent safety practices.

“Platinum prices are likely to rise further as a result.’

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