Civil Engineering Bulletin: News, forums, jobs, software, freelance and ebooks - Southern hemisphere's largest concentrator under construction

he company says that, once completed, the new concentrator will be the largest concentrator in the southern hemisphere.

The R400-million civil works Northern expansion project contracts were awarded by negotiation rather than tender, and Grinaker-LTA Civil Engineering was chosen for its previous experience, capabilities and management team.

“Vhumbanani, which is responsible for the design and management of the project, handled the negotiations and we feel that their approach to appointing contractors made a lot of sense,” says Grinaker-LTA Civil Engineering contracts manager Peter Meidlinger.

Since being awarded the initial contract and starting work on site in August 2006, Grinaker-LTA Civil Engineering has been asked to construct two additional structures – the concrete frame for a substation, and a 13-m-diameter/30-m-high storage silo.

The new concentrator plant will be used to crush mined ore and process it to form a concentrate, which is then further processed in the conventional platinum- refining process.

The civil works for the new plant, which is to be completed in August this year, will be linked to the existing plant by conveyor systems.

In addition to these structures, the main structures being built by Grinaker-LTA are the high- pressure grinding roller feed silo, the mill feed silo, the high-pressure grinding roller crushing building, the vibrating grizzly building, the secondary screening building, the secondary crushing building, the high-pressure grinding roller screening building, and 13 linking conveyors.

The two large silos, 18 m in diameter and 55 m high, form half of the project. The first silo base (high-pressure grinding roller) was completed in early November last year, and required 1 300 m� of continuously poured concrete.

To facilitate the concrete pour and obviate the need for trans-porting concrete, a tower crane and a concrete batch plant was positioned next to the silo. This resulted in considerable cost and time savings.

Grinaker-LTA Civil Engineering has been assisted in the construction by its sister companies, Karrena Africa, which was responsible for the slipforming of the three silos, and Steeledale Reinforcing, which is supplying the reinforcing steel. All the concrete required for the various buildings and con- veyors is supplied by the com- pany’s own batch plant on site. Other plants provided by Grinaker LTA Civil Engineering’s plant division include three mobile cranes, two tower cranes, and three 6-m� spinner trucks.

The Grinaker-LTA Civil Engineering site is managed by project manager Trevor Morris, assisted by a capable staff team and 350 hourly paid labourers, 65% of whom are from the local community.

Source : Mining Weekly