Russian steel giant NLMK Group, the largest steelmaker in Russia and, according to the company, one of the most efficient in the world, is embarking on the second stage of a project to implement High Pressure Grinding Rolls (HPGR) technology at its Stoilensky beneficiation plant.

Four HPGRs were installed in 2016 at two of the four sections of the beneficiation plant. HPGR technology, claimed to be 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. The upgrade will increase each section's capacity by an average 10-12% and significantly reduce energy consumption, grinding balls and lining. The new HPGR units have already arrived at Stoilensky and the company plans to commence hot testing in December.

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 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.

“The implementation of high-pressure ore grinding at Sections 1 and 4 of Stoilensky’s beneficiation plant increased our concentrate output by 1Mt/yr, said Konstantin Lagutin, NLMK Group’s vice president for investment projects. He said that HPGR technology has proved to be efficient and reliable, prompting the management to roll out the technology to the plant's 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 37Mt, bringing concentrate output up to 17.4Mt/yr 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.”