11.05.2021

Sever Minerals Continues to Improve Efficiency of Stoilensky GOK

Stoilensky Mining and Processing Plant is part of NLMK Group and carries out complex processing of iron ore raw materials.

As part of the customer's development strategy to increase the capacity of the Stoilensky Mining and Processing Plant from 43 to 47 million tonnes of base ore, Sever Minerals engineers proposed a unique solution.

Sever Minerals team developed a project to increase the capacity and quality of the resulting product by using the gravitational technology of screw separation and including weakly magnetic iron in the processing, which was previously lost with the tailings* of wet magnetic separation.

The idea of using screw separators is new to the iron ore industry. They are mainly used in gold mining enterprises to extract free gold. Sever Minerals pioneered the application of this technology to iron ore in a project for the Olenegorsk Mining and Processing Plant and proved the stated effectiveness of this solution. 

The gravity separation process depends on the qualitative characteristics of the feedstock to each deposit, including the specific gravity of particles, mineral and chemical composition. This technology has not been previously applied at the client's factory, while industrial tests are a prerequisite for the client. Sever Minerals provided the customer with the opportunity to test the technology at their own factory.

“The testing goal was to confirm the effectiveness of the technology in an industrial environment. We have developed an installation that is as close to real working conditions as possible. This solution is a small modular plant, fully designed, configured and assembled by the engineers of Sever Minerals,” — says Lead Engineer for Classifying and Separation.

The mobile pilot installation allows to combine and implement various process flows and move it relatively quickly to other plants for similar tests.

The unit consists of three Multotec screw separators, three Metso VT-50 vertical pump units with receiving tanks and circulating pipe sleeves. An additional fourth tail tank allows to collect the resulting products and return them to the technology without losing the customer's raw materials at the time of testing. The solution also includes WEG electric motors and Danfoss frequency converters.

The installation is easy to maintain: it is connected to the water supply of the factory, equipped with flushing devices and hydraulic slurry mixers in the receiving tanks. Due to the design features of the installation, it is possible to provide a long-term autonomous operation mode for the formation and selection of the presented samples.


*Cleaning rejects of minerals, consisting mainly of waste rock, i.e. with a minimum content of the useful component.