“The main civil contractor at Dwaalboom is Concor Civils,” states senior projects manager Arthur Shirley. He notes that about two-thirds of the bulk earthworks is complete, which constitutes part of the main civils contract. Two contractors have been appointed for the piling, that is being placed to remedy the diffi- cult founding conditions at the Dwaalboom site. This includes the auguring of a total number of 122 on-site cast piles to stabilise the structures.
Stefanutti & Bressan is making progress with the clinker storage silos, while FrankiAfrica has completed the preheater bulk earthworks and piling. Shirley notes that the civil construction in progress includes the following works: two 20 000-t clinker storage silos; pile caps for the preheater structure; kiln piers, a clinker cooler, a cooler ESP, a clinker tunnel and “off-spec” clinker system; cable tunnels, site drainage and stormwater reticulation are in progress; the setting out of the raw mill, coal mill and substation portions are in progress; and the bulk earthworks for the mills are set to commence shortly. The risk assessment for the preheater civil construction and the structural steelwork interfaces has been completed. This structure will be the largest of its type in South Africa, being over 100 m high with a 25 m by 25 m footprint. The structure will have eight major floors to support the preheater cyclones. The contract for the supply and erection of the preheater structural steelwork has been awarded to DMCE and the steel detailing is under way. Shirley adds that an enquiry is to be issued for the final civils package which includes bases and foundations for blending beds and the raw materials handling section. He also notes that all permanent accommodation contracts are completed. These include 17 new houses, one new office building, extensions to the existing administration block and a new ablution facility. The civil engineering and design portion of the contract was awarded to the ConsulTauri/Axis JV and is 70% complete.
The Dwaalboom expansion also includes upgrades to existing clinker-conveying equipment and the installation of new conveyors and storage facilities to handle the new kiln production of one-million tons of additional clinker. Shirley states that the local mechanical design of the clinker handling is now about 80% complete. Bateman Engineered Technologies is expected to deliver the local dust-control equipment and the local conveying equipment in January 2007, and cold commissioning is sche- duled for August/ September 2007.