Construction World December 2015

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Impumelelo Shaft Project

diversion was made to enable the casting of the centre abutment. Concrete augured piles with an 800 mm diameter were cast in situ through the river bed to a maximum depth of 15 m in order to support the new bridge. The underground surge bunker beneath 4 Seam provides surge capacity as well as a constant flow of 2 900 tph to the incline conveyor. The live capacity is 1 500 t, aimed at controlling surges during peak production and to feed onto the incline conveyor via vibrating feeders. The longest single flight overland conveyor in the southern hemisphere was constructed on this project. It has a length of 27 125 m and a design capacity of 2 400 tph. Four underground trunk conveyors provide the coal feed from section conveyor belts to the underground surge bunker with a maximum design capacity of 3 600 t/h. Three shafts had to be sunk, two vertical and one decline, to a depth of 240 m, with the decline being 1 060 m in length. Both the vertical shafts were sunk to 4 seam only and the decline shaft to the 2 seam coal horizon. An 11,7 m diameter coal bunker will be established between the 4 and 2 seam horizons. Two seam reserves were excluded in the shaft area and sub-declines will be developed from the four seam coal horizon at a later stage to establish the necessary infrastructure on the two coal seam horizon.

Project information • Company entering: Hatch Goba • Project start date: 2009 • Project end date: October 2014 • Client: Sasol Mining • EPCM consultant: RSV ENCO Hatch Goba Coal Joint Venture ture was built for the 62-month, R4,6-billion multi-disciplinary Greenfield project, which had an integrated management team at its helm. Specialised package managers were responsible for total delivery within their areas of responsibility. Sasol Mining’s Impumelelo Shaft Project is a new 8,5 Mtpa (expand- able to 10,5 Mt/a) replacement tonnage coal mine complex to its Brandspruit Mine, located in the Secunda area, Mpumalanga. Sasol Mining appointed the RSV ENCO Hatch Goba Coal Joint Venture as the Engineering, Procurement and Construc- tion Management (EPCM) consultant, which brought together expertise in mate- rials handling, civil engineering design, mechanical, electrical, shaft-sinking, project management, procurement, construction management and coal mining. A total of 24 500 m 2 of surface infrastruc-

The basic engineering design packages ensured suitability, functionality, constructa- bility, operability and maintainability of the new mining infrastructure and associated materials handling system. All the systems were designed to be energy efficient and optimised within strict coal degradation and spillage tolerances. The joint venture’s multi-disciplinary team had to interface between the Sasol project team, the Sasol Mining team and the Sasol Coal Supply team, which would ulti- mately run the entire operation and there- fore had to be brought up to speed with the project’s technical scope. A techno-economic review of the project’s feasibility was completed by the joint venture in June 2009, followed by a detailed engineering design phase from July 2009 to December 2010. Construction began in earnest in June 2011. Phase I construction was completed in June 2015, with Phase II scheduled for completion in June 2019. Upon completion, Impumelelo Mine will have 13 production seams, with a total shaft depth of 235 m. The project scope entailed the design and development of the complete Greenfield mine complex. For this reason, special consideration had to be paid to the build-up of the new operation, in conjunction with the phasing out of the existing coal-mining operation. During construction, a temporary river

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CONSTRUCTION WORLD DECEMBER 2015