Concor Opencast Mining has been involved in several major contracts in recent months which have consistently demonstrated to the market that it has the necessary experience, capacity and resources to implement world class opencast mining operations. Underpinning this robust track record are a sound safety performance, the safeguarding of critical skills and the upskilling of local communities. The company is a leading local specialist in the open-pit mining of steeply-dipping, narrow hard rock orebodies. However, Anton Cilliers, General Manager of Concor Opencast Mining, emphasises that its expertise covers the entire spectrum of open-pit tasks, including the removal of overburden, surface blasting design and execution, crushing and screening, as well as tailings dam construction and rehabilitation.
The company has a reputation for providing innovative solutions and for delivering projects safely, on time and within budget, with an ability to minimise the impact of working close to existing mine infrastructure. At the same time it is committed to uplifting local communities, recruiting members of the workforce from these areas and facilitating ongoing skills development among these personnel.
“Our team is passionate about the work we do and that smell of diesel fumes mixed with dust is what gets our blood pumping in the morning. Watching big mining machines in action exhilarates us,” says Cilliers. “There’s never a dull moment on opencast sites because they change constantly as the pit develops. I believe that right now the mining industry as a whole is probably facing the biggest challenges of its existence and this makes the game we’re in even more interesting because we need to change with the industry or be left behind.”
Among the contracts the company has recently attracted is a 36-month Anglo American Platinum project, awarded in August 2013, to construct a tailings storage facility (TSF) and undertake related interface construction at the Blinkwater tailings dam on the Mogalakwena mine near Mokopane, Limpopo Province.
Some 7.2 Mt of waste rock will be needed for the construction of the dam over the contract period, hauled over a 5 km distance to the construction site. Interface work comprises layer sealing the dam on the inner face of the TSF impoundment wall, compacted to 95% Proctor density.
Auxiliary works have also been awarded as a separate contract including top soil removal. A notable challenge on this project is the need to work in confined spaces, particularly on the interface section, where road width is confined to 6 m.
At African Exploration Mining & Finance Corp’s Vlakfontein coal mine near Ogies, Mpumalanga, Concor Opencast Mining has won a 24-month extension to its original 36-month contract awarded in November 2011. The pit was designed for six years and, based on the team’s good performance and safety record, the contract has been extended to cater for this. The project involves open-pit coal mining to a depth of approximately 39 m and extracting 130,000 t/month of coal. It includes hauling coal to a coal crusher on the mine property.
The company has successfully completed a mining contract for Impala Platinum that spanned 13 years. Work began on this open-pit project in 2002 in the vicinity of Impala # 6 shaft with mining of the Merenksy ore body and, in 2005, Concor Opencast Mining began mining the UG2 orebody.
The two Merensky faces were relatively small scale, while the UG2 was on a much larger scale with seven faces mined until all surface-mineable resources were depleted. These reefs ranged over a 9 km area to a depth of 35 m. Although the project took place in close proximity to mine infrastructure and to houses occupied by members of the local community, the impact of mining operations was successfully kept to a minimum.
At the end of the project the mining team had recorded more than five million fatality free hours, or 1,196 LTI-free days, and earned several Impala Platinum and Concor Opencast Mining safety awards for safety milestones attained along the way.
At Lonmin’s Marikana mine in North West Province, Concor Opencast is nearing the end of a mine deepening contract that began in October 2009. The project has about 10 remaining months of ore extraction, after which rehabilitation will be implemented for a further 18 months.
In January 2014 Concor Opencast handed over another successfully completed contract to Amplats— the 21-month Khuseleka project near Rustenburg that involved mining outcropping Merensky reef to a depth of 20 m.
Total mining volumes include 280,000 bank m3 of topsoil, 295,000 bank m3 of box cut overburden, 830,000 bank m3 of strip mining overburden and 820,000 t of Merensky reef. Conditions on the project were challenging, owing not only to an orebody that dipped steeply and which was relatively fractured, but also because mining took place close to mine infrastructure. Electronic blasting was implemented to mitigate the impact of mining operations, enabling a marked reduction in noise and vibration. On this project the team recorded 627 LTI-free days.
In joint venture with Basil Read, Concor Opencast has been contract mining iron ore at Assmang’s Beeshoek mine at Postmasburg in the Northern Cape since November 2011. The contract called for extensions to the perimeter of an existing pit and mining it to a depth of about 190 m. Volumes moved during the 32 month mining period are estimated to be about 48 Mt of waste, comprising overburden shale, ferruginous waste and chert, together with about 5.5 Mt of iron ore. The contract was recently converted to a plant hire agreement, which has been beneficial for all parties.