NLMK Group, an international steelmaking company with operations in Russia, the USA, and the European Union, is embarking on the second stage of its project to implement High Pressure Grinding Rolls (HPGR) technology at the Stoilensky beneficiation plant, NLMK Mining Division core asset.

Four HPGRs were installed in 2016 at two of the four sections of the beneficiation plant. The HPGR technology, unparalleled in Russia, has delivered a 12.5% increase in the processing capacity of each upgraded section.

The second stage involves the installation of four HPGRs at the remaining two sections of the plant. New buildings that will house these rollers are currently under construction. This upgrade will increase the capacity of each section by an average 10-12% and significantly reduce the consumption of energy, grinding balls and lining. The new HPGR units have already arrived at Stoilensky. NLMK Group plans to commence hot testing in December this year.

The HPGRs will supplement the conventional conical crushers and ball grinders currently employed. One HPGR unit can replace two of the conventional crushers in widespread use in Russia. The high pressure applied by the rollers of the HPGR units not only crushes the ore but also breaks up its crystalline structure. As a result, the downstream stages at Stoilensky receive ore that is more ‘ductile’ for further grinding, which delivers a significant increase in productivity and enables a substantial saving of resources, such as grinding charge, balls and electricity.

Konstantin Lagutin, NLMK Group’s Vice President for Investment Projects, said: “The implementation of high-pressure ore grinding at Sections 1 and 4 of Stoilensky’s beneficiation plant increased our concentrate output by 1 million tonne per year. The HPGR technology has proved to be efficient and reliable, which enabled the management’s decision to roll out the technology to the remaining Sections 2 and 3. This effort should add almost 800,000 tonnes to Stoilensky’s annual output.

This measure together with our other initiatives will enable us to expand our mining and ore processing capacities to 37 million tonnes, bringing concentrate output up to 17.4 million tonnes per year by 2018. This will cover 100% of the Group’s needs in iron ore. Investment in HPGR technology and expansion of ore extraction will amount to 4.5 billion rubles. This is the most significant of Stoilensky’s remaining Strategy 2017 investment projects.”

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