DIAMONDS AND GEMS

De Beers launches its first South African marine diamond mining vessel

De Beers' Peace in Africa diamond mining vessel is expected to produce 240,000 carats annually from a new offshore mining area off the South African coastline.

Author: Tessa Kruger
Posted: Saturday , 21 Apr 2007

JOHANNESBURG - 

De Beers Consolidated Mines (DBCM) named and blessed its first marine diamond vessel that will mine off the South African coast today after years of work to prove a substantial reserve and enhancing technology to mine it viably. This will be the company's first South African offshore mining project, although it already produces a considerable number of diamonds using similar technology off the neighbouring Namibia coastline.

The diamond mining ship, named Peace in Africa, was inaugurated in both Western and African traditions in Cape Town before the R1 billion ($142 million) vessel of 176 metres long and 28m wide sails off next week to produce an estimated 240,000 carats annually off the Namaqualand coast on South Africa's Atlantic coast.  The vessel is equipped with a large undersea tracked mining tool (crawler) and has a specialised diamond recovery treatment plant, manufactured by specialist Bateman Engineering, on board.

Project manager for the "mine on a ship", Glenn Back, said the blessing of the vessel was a landmark achievement for De Beers that was already mining with similar crawler technology in Namibian waters.

The company had enhanced its crawler technology, already used in its offshore Namibian operations, to mine an 8,000 square kilometre reserve in South Africa at a higher square metre per hour compared to operations in the neighbouring country.  Another feature of the enhanced crawler technology is that it provides a three dimensional visualisation of the seabed and mining operations here.

Making the project exceptional is its grade of 0.1 carats per square metre and the fact that 95% of diamonds found are expected to be of gem quality.

And although the size of the reserve is substantial, only about 0.5% of the reserve will be mined by the Peace in Africa over a mine life of 30 years. 

The 260 ton seabed crawler unit, which undertakes the actual mining, is connected to the ship by a 650 mm internal diameter umbilical through which the seabed material is pumped to the plant using a 2MW pumping system.

The ship and crawler will work up to 35 km offshore and at depths of up to 200 metres.  Mining will be undertaken in 100m x 500m blocks.

It is anticipated that the vessel will remain at sea continuously for 2 ½ years before returning to port for a refit.  The crew works on board for 28 days (12 hours on, 12 hours off) followed by 28 days leave and is flown in and out by helicopter in a similar pattern to that for offshore oil rigs

If the vessel manages to uncover the right sort of grades continually, De Beers will consider expanding its fleet of diamond mining vessels to exploit a greater part of the resource at a greater pace, said the manager.

De Beers will explore the remaining 95% of the diamond reserve on an ongoing basis in order to stretch the project life.

The project manager said De Beers was exploiting the off-shore resource as the company was committed to growth and the project was an economic one.

"It is a significant achievement for De Beers as it took us a number of years to build confidence on the project."

He also pointed out that the company was "excited" about the fact that it was contributing to the upliftment of the area and boosting employment in the Richtersveld, located in the   Northern Cape province of South Africa.