Alrosa Aiming to Extract Higher-Value Rough

RAPAPORT… Alrosa is expanding its use of X-ray technology in an effort to recover rarer and larger rough diamonds before the sorting system crumbles them into pieces.

The Russian company is trialing upgraded equipment at its Udachny mine in Yakutia so it can identify type IIa stones measuring 6 millimeters or more, a spokesperson told Rapaport News last month. The previous technology only picked out Udachny’s lower-value diamonds, so the larger and purer ones risked slipping through the extraction process and going to the crusher.

Type IIa crystals account for 1% to 2% of the world’s diamond production, Alrosa noted. They are distinct because of the absence of nitrogen or boron, and tend to be colorless and the chemically purest of diamonds. Their rarity and quality make the rough highly valuable, especially in larger sizes. However, Alrosa currently configures the Udachny separation machines to detect mainly type Ia diamonds, which are far more common and more likely to have imperfect color.

The technology uses diamonds’ capacity to glow under X-ray light in different ways from other minerals, enabling miners to spot them in a mixture of materials. The improved system, which Alrosa has already trialed at its Aikhal and Severalmaz mining divisions, will be tuned to the type of luminescence unique to type IIa diamonds, the company explained.

The results of the tests at Udachny will determine whether Alrosa will roll out the program more widely there. The earlier pilot at Aikhal, which took place in 2019, found that around 2% of the division’s production was type IIa. The company plans to introduce the technology at the Mirny division in 2021.

Image: Rough diamond. (Alrosa)