Name of the Project
Impumelelo replacement coal project.

Location
Mpumalanga, South Africa.

Client
Sasol.

Project Description
The move to develop the mine forms part of what Sasol has previously described as an “intense capital replacement” programme involving four significant projects – Thubelisha, Impumelelo, Shondoni and Tweedraai – which will replace the long-serving Twistdraai, Brandspruit, Middelbult and part of the Syferfontein operations respectively.

Impumelelo, in Secunda, Mpumalanga, will replace the old Brandspruit mine and produce coal for the Sasol Synfuels plant.

The project involves the construction of a new 8.5-million-ton-a-year coal mine, which is upgradeable to 10.5-million tons a year.

The No 4 and No 2 coal seams will be mined simultaneously at the project, with the thinner and more complex No 2 seam lying below the No 4. The final shaft depth will be about 225 m below the surface.

The project includes the development of service, ventilation and decline shafts, materials handling systems (including a 28 km overland conveyor, surface surge bunkers, underground conveyors and surge bins) and all the mine infrastructure needed to support operations.

The 11.7-m-diameter men-and-materials shaft will be 210 m deep, with a four-sided station on the No 4 seam.

The 6.7-m-diameter ventilation shaft will also be sunk to 210 m, with access through the four-sided station to the coal production sections.

The shaft complex has been designed to operate for a minimum period of 35 years.

The conveyer system will deliver coal to the Synfuels complex, becoming the longest conveyer system of its kind in the southern hemisphere.

Jobs To Be Created
Not stated.

Net Present Value/Internal Rate of Return
Not stated.

Value
The project is estimated at R4.6-billion.

Duration
The project is expected to be completed in 2019.

Latest Developments
The reaming phase of a 7.3-m-diameter hole at the Impumelelo coal mine has been completed, setting an African record for the largest-diameter hole reamed to date, says South African mining company Redpath Mining.

Mining Weekly reported in June that the Impumelelo colliery, an 8.5-million- to 10.5-million-ton-a-year operation that is part of Sasol’s programme to replace its ageing coal mines in the Secunda area, was 40% complete.

Sasol awarded Redpath Mining the contract for two ventilation shafts at Impumelelo in 2016. The scope of work includes the piloting and reaming of two ventilation shafts, which are 186 m deep with a diameter of 7.3 m. This includes the lining of both shafts using a remote shaft liner. The first shaft is the Up-Cast shaft and the second will be the Down-Cast shaft.

The Redbore 90EX is being used to raisebore the shafts. The Redbore 90EX is being mobilised at the Down-Cast shaft, while the remote shaft liner is being set up at the Up-Cast shaft. Shaft lining will be executed by spraying a 100-mm-thick 30 MPa fibrecrete lining onto the sidewall of the reamed hole to prevent the shaft from caving in. This will be undertaken using a remote-controlled unit from the surface, which means that no workers will be involved or in danger.

Mobilisation started on December 19, 2016, with the Up-Cast shaft piloted in early January. Using a rotary vertical drilling system, the pilot hole was directional-drilled to a depth of 82 m, where conventional piloting continued until breakthrough on January 28. With reaming starting on February 16, the reamer chamber had to be prepared. It was jointly designed by Redpath and air compressor repair services company Atlas Copco.

Key Contracts and Suppliers
RSV Enco-Goba coal joint venture, or JV (engineering, procurement and construction (EPC) management implementation); Murray & Roberts Cementation (men-and-materials and ventilation shafts, as well as decline coal seam development on the No 2 and 4 seams); Concor Civils (subcontracted to provide temporary civil works for sinking and development); ELB Engineering Services (EPC – materials handling conveyor); Veyance Technologies (manufacture and delivery of steel cord conveyor belting); Cascade Logistics (transportation of belt rolls); Goodyear Engineered Products (cover compound) and Flexco (manufacture and delivery of a new vertical belt reeler), Redpath and Atlas Copco (reaming of ventilation shafts).

On Budget and on Time?
Phase 1 of the Brandspruit replacement project was completed in June 2016, while Phase 2 “progressing well”, and is on track for completion in June 2019.

Contact Details for Project Information
Sasol group media manager Alex Anderson, tel + +27 71 600 9605 or email alex.anderson@sasol.com.