On 21 June 2004the first diamonds were recovered at the new Istok alluvial deposit outside the Arctic Circlein Sakha (Yakutia).

As the bulk of start-and-adjustment work at the mobile ore treatment module was completed, the first bucket of diamondiferous sand was processed and the first diamonds recovered.

This is a significant event for ALROSA not only because recovery began at a new diamond deposit, the license for which was only obtained in May 2004. It heralds the appearance of a new advanced mobile method of diamond recovery suitable for remote and difficult to access alluvial placers, and thus opens a new page in the company’s history.

What is special about diamond recovery at placer deposits is that dredging is typically done along the creeks some 10 km long, and transportation of big amounts of sand to the permanent ore treatment facility can be too costly. Thus a compact, easy in maintenance and simple to control mobile unit that can be transferred from site to site in any road conditions is very welcome.

Four years ago ALROSA adopted a program for the development of such mobile ore treatment modules. In 2002-2003 the first such unit was tested at the Yras-Yuryach placer also developed by the company’s Anabar division.

The new and more advanced dense-media separation unit was jointly designed by ALROSA and the Krasnoyarsk Spetstechmontazh mechanical engineering plant. The RUR 50 million unit with a capacity of 200 thousand cubic meters per year was manufactured in Krasnoyarskand assembled with the assistance of foreign specialists. During one dredging season, i.e. from June to September, commercial recovery by the module in terms of value is expected to amount to US $ 20 million.

The module is operated by a team of 5 workers. It consists of 3 main units for sand preparation, treatment, and concentration of diamonds in four X-ray luminescent separators. The concentrate will then be taken to ?12 Processing Plant in Udachny for final recovery and sorting.

Efficiency of dense media separation method in diamondiferous sands treatment is very high – the concentrate output is 20 times less, with only 1 per cent of the material treated to become the concentrate. It significantly reduces transportation and energy costs, and, most significantly, enables high recovery rate.

Already next year production at the Anabar division, the world’s northernmost diamond mining facility – will grow from US $ 30 to 50 million per year.

The Istok alluvial deposit is one of the EbelyakhRiverplacers located in the Anabar Region of Sakha (Yakutia), 250 km of the Arctic Oceanand 70 km of the administrative center, the town of Ebelyakhwith its airport and the company’s main processing facilities.