PRESS RELEASE: The Cullinan mine is owned 74% by Petra Diamonds and is renowned as the source of very rare blue diamonds and large, high quality gem diamonds, including Type II stones characterised by low nitrogen content (their volume not exceeding 1−2% of the world production).

The decision to implement Bourevestnik’s sorters was taken by Petra Diamonds after assessment and comparison of diamond recovery technologies available in the market relative to the unique characteristics of the Cullinan ore. This process confirmed the high recovery efficiency of all types of diamonds by the Bourevestnik sorters, including low-luminescent Type II diamonds characterised by low luminescence level under X-ray exposure.

As part of this project, Bourevestnik has supplied 27 sorters, specifically upgraded as per Petra Diamonds’ requirements, for primary recovery, reconcentration and final concentrate treatment of diamond bearing ore, with a sizing range of -75 mm +1 mm. Processing of run-of-mine material with a size fraction of -75 mm +6 mm is done directly via X-ray sorters without the application of dense media separation. In addition to supplying equipment, Bourevestnik has performed commissioning, technical personnel training and arranged consignment stock of spare parts.