A sweeping R15.3-billion project that will replace three of petrochemicals group Sasol’s ageing coal mines across the Secunda coalfields of Mpumalanga continues to advance within budget and will, once fully completed in 2016, supply the group’s nearby Synfuels complex with 42-million tons of coal a year for the next 35 years.

Noting that the group’s Twistdraai, Brandspruit, Middelbult and Syferfontein reserves were nearing the end of their economically mineable life, Sasol Mining senior VP Peter Steenkamp told journalists during a tour of the sprawling complex last week that the mining of the remaining available reserves remained the most viable way of securing coal supply to the adjacent Synfuels operation.

According to a 2013 report, total extractable run-of-mine reserves in the Secunda area totalled 1.3-billion tons.

“The cost of keeping the old mines going was high, owing to old, expensive conveyer belt systems, but mining the reserves in Secunda is still the cheapest way of producing coal... even though they need to be underground and deep,” he said.

He added that sourcing coal from its own mining operations, rather than relying on a third-party source, also provided Sasol with flexibility of supply, while maintaining reliability and sustainability.

As part of the replacement project, which would transform the Secunda area into one of the largest underground coal complexes in the world, the Twistdraai mine would be replaced with the Thubelisha mine, the Brandspruit operation would be replaced with the Impumelelo mine and the Middelbult operation would be expanded to create the Shondoni mine.

In addition, an upgrade project at the Syferfontein mine will provide high-wall access into the newly acquired BlockIV reserves.

The overall project will result in the construction of three 65t payload mining shafts and three 2700t/h incline shaft systems, as well as several coal-handling facilities and 66 km of conveyer systems.

Construction of the new 10.5-million-ton-a-year Thubelisha mine started in March 2009, with first production achieved in January 2012.

The R3.2-billion operation has 12 production sections and a shaft depth of 160m, while a 17-km-long conveyer system transports 2500t/h of coal to the nearby Synfuels complex.

First production from the R4.7-billion Impumelelo mine, which will replace the Brandspruit operation, is expected later this month, followed by the completion of Phase1 construction in June and the completion of Phase2 in June 2019.

Once completed, the 10.5- million-ton-a-year operation will boast 13 production sections and reach a shaft depth of 235 m.

A 2 400 t/h, 28-km-long conveyer system will deliver coal to the Synfuels complex, becoming the longest conveyer system of its kind in the southern hemisphere.

To the north of Impumelelo, the new Shondoni mine, which will replace the ageing Middelbult operation, is currently about 63% complete and will eventually reach a depth of 150m and deliver up to 10.5-million tons a year of coal.

First production from the R3.09-billion mine is expected in January 2016 and will be delivered to the Synfuels operation by a 21-km-long 2400t/h conveyer system.

The Syferfontein mine will, meanwhile, be extended at a cost of R1.4-billion to include a high-wall access into BlockIV.

Construction on the project started in May 2013 and will likely be completed by July, delivering a 7.2-million-ton-a-year mine. The project will also see the construction of a 4 800 t/h, 1.5-km-long coal conveyer system.