ALROSA recently launched a tailings thickening complex at the processing facility N12 of Udachny mining and processing division. The project, which costs over RUB 3 billion, will significantly reduce water consumption and increase the efficiency of tailings storage, the waste rock left after kimberlite ore processing.

The tailings thickening complex comprises of a pump system, a cyclone cluster, and two 28 m in diameter thickeners. The complex uses centrifugal force to extract most of the recycled water from the tailings. The water is further reused, and the remaining sand after thickening goes to the tailings pond.

The project allows ALROSA to change the tailings storage scheme and significantly extend the operating life of the plant’s existing tailings pond. “Tailings thickening makes production more environmentally friendly, reducing by 85% the amount of water resources consumed by the processing facility. Previously, about 6,500-7,000 cubic metres per hour were used, and only 1,000 cubic metres per hour are required today, the rest is replenished with recycled water. At the same time, the placement of thickened tailings by the cone method will allow safe use of the existing tailing dump until 2066,” noted Roman Deniskin, director of Udachny mining and processing division.

Implementation of the project took several years. The investments amounted to about RUB 3.3 billion (some $42 million). The complex is the second project of its kind implemented by the company. Previously, an alternative method of tailings thickening with the use of other technology was introduced at the processing facility N16 of Nyurba mining and processing division.

“ALROSA consistently reduces the environmental impact and risks of tailing dumps operation. Today, the company develops project for drainage and reclamation of the tailings dump at the processing facility N8 of Aikhal mining and processing division.”

According to PwC research made in 2019, ALROSA ranks first among its peers in terms of volumes of circulating and reused water. In 2019, the volume of water for circulation and reuse was 4.1 million cubic metres, or 55% of total water consumption. Total volume of circulating water and water reused in the process cycle amounted to 222.4 million cubic metres. In the course of three years, the total volume of circulating water supply in ALROSA grew by 40.5%.