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Removal of overburden for bauxite mine, Klaverblad

Surinam’s alumina exports accounted for 70% of the total export figures. Aluminum is produced from bauxite and so bauxite mining was one of the country's vital industries. Growing demand for metals in fast-growing economies led BHP Billiton Maatschappij to open up a fourth mine alongside the three bauxite mines they already operated in Surinam. The mine location on the banks of the River Surinam was covered by a thick layer of clay. Borehole information and surveys showed that an area of about 130 ha needed to be cleared of bush, followed by the removal of the top layer and dewatering to an average depth of 14 meters. Safety and the prevention of dredging-related turbidity in the river were areas requiring particular attention.

Nearly the whole site was covered with secondary bush. So the first stage of the operation started in November 2004 with bush-clearing and shredding. The shreds were spread over the top layer and their dimensions were such that they could be dredged hydraulically without clogging the pumping system. Meanwhile, the clamshell dredger Elisa started digging a ring channel, an access channel and an initial pit for the CSD Edax. The ring channel was also constructed as a levee to enclose the dewatering site and prevent flooding of the nature in the vicinity. The Edax commenced dredging in July 2005 and her output was pumped into a disposal site near the old Rorac mine. The process water could not be discharged into the river and so it was pumped 12 kilometers to the old Para Mine with the booster stations Nieuwe Merwede and Energie III. In the meantime, the TSHDs Gemma and Flevo brought in river sand for the construction of a cofferdam that, in combination with the levees, completed the total enclosure of the mine. The heavy rains meant that extra sand had to be brought in to strengthen roads and other critical points at different locations on the site. Dewatering of the mine started in August 2006, with the water being taken to the settlement locations to prevent turbidity in the river. Edax stopped dredging a few weeks later.

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Dredging of sediments, Miami river

The Miami River, which flows through an urban industrial area of Miami, Florida, had not been dredged since the area was built in 1934. In 1990 the US Army Corps of Engineers advised the city that the sediment had to be removed from the river as it was impeding shipping. There was one caveat however: the sediment, contaminated with heavy metals, pesticides and oil, could not be placed in the ocean.

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Gas fields development, Krishna Godavari basin

A large-scale dredging, trenching, pipe pulling and backfilling project. Reliance Industries develops the offshore gas field known as Block KGDWN-98/3 in the Krishna Godavari Basin, Bay of Bengal off the East Coast of India. The gas field will be linked to onshore customers and covers an area of approximately 7,500 km2. The field stretches an area 40 to 60 kilometers southeast of Kakinada. The scope of works comprised the dredging of a 21 kilometers long and 18 meters wide trench for three 24" gas pipelines, each with a 6" piggyback pipeline, one 12" effluent pipeline and two umbilical cables in water depths ranging from 0 to 50 meters. After pipe laying by the main contractor the pipeline trench was backfilled with partly rock and sand.

Rehabilitation of old breakwater, Port of Poti

The city of Poti is located at the mouth of Georgia’s largest river, the Rioni. It has been an important trade centre for centuries. Since the early 19th century, many plans have been developed for the creation of a major sea port. Construction work started in the 1850s on the main breakwater that is still protecting the port today. During its long lifetime, this structure has been maintained by frequently adding 20-60 tons of concrete cubes to the armour layer. Significant settlement of the structure over time has lowered the crest level considerably, resulting in large overtopping volumes and therefore in port-operation downtime. As a result, a rehabilitation project was executed between 2006 and 2008 by Royal Boskalis Westminster N.V. to reduce the downtime caused by overtopping waves.

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Reclamation and dewatering works, Sepetiba Bay

The German steel-maker ThyssenKrupp Steel and the Brazilian mining giant Companhia Vale do Rio Doce (CVRD) teamed up to construct a EUR 3 billion steel factory at Sepetiba. This is a small town of 36,000 inhabitants near Rio de Janeiro with good access to the Atlantic Ocean. The new steel factory allowed Brazil not only to export more of its plentiful mineral resources, but also to produce semi-finished products that can be sold at higher margins. The government authorities of Brazil and Rio de Janeiro both supported the project.

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Port development, Lerwick

The Port of Lerwick is situated on the east coast of the Shetland Islands, and is operated by Lerwick Port Authority. The 2008 dredging and reclamation works were one of the largest marine projects to be carried out in Scotland in recent years and constituted the largest single investment in the port to date.

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Port construction, Vuosaari

Vuosaari Harbor is the most significant harbor project in Finnish history; in fact, it is unique even on a European scale. Both existing harbors in Helsinki’s city centre are being transferred to the eastern outskirts of the city. They are being replaced with a harbor with excellent traffic connections that can meet the increasing demand for cargo handling. The Vuosaari Harbor Center will provide a competitive and modern service package, with smooth connections between harbor operations and other logistical facilities. The harbor center will comprise the gate area, the closed harbor area and the adjacent Business Parks. The fairway to the Harbor Center will be 32 km long, at least 200 m wide, and 11 m deep. The port area comprises 150 ha, of which 90 ha will be land reclaimed from the sea.