De Beers Marine Technology Enabling Mining At Greater Depths

(IDEX Online) – De Beers is searching for diamonds in deeper water off Namibia’s coast as a result of technological advances that it has led which have enabled it to create enormous mud-sifting machinery.

A crawling machine weighing close to 300 tonnes and three stories high recovers diamonds by vacuuming up sand and silt at a depth of 100 metres and even more.

Offshore diamond mining started just over 50 years ago at depths of less than 35 meters, but technological developments in the past decade have facilitated operations in deeper water.

"Ten years ago a crawler would be mining at about 200 to 250 square meters an hour. Today we believe that our crawler would mine at about 1,000 square meters an hour," De Beers Marine General Manager Domingos Valbom told Reuters.

Debmarine Namibia is a 50/50 joint venture between the Namibian government and De Beers.

"It is the best way to extract marine diamonds, but the geology in which we operate has to lend itself and the crawler has to have a surface to operate," Valbom said of the "horizontal mining" process.

When the sea bed becomes too rocky and uneven for the giant vacuum, the firm can switch to "vertical mining" by four other ships, which each use a large-diameter drill to bring diamond-bearing gravel to the surface.

"The crawlers have made a step-change in our mining and to our productivity and the financial performance of marine mining," Valbom said.

He also said the company aimed to improve the efficiency of the crawler, which could be used to suck up other minerals such as gold.