Technology

Lebedinsky GOK’s technological process includes the following stages:

Mining operations
Lebedinsky GOK conducts a complex of activities on ferrous quartzites mining and processing from the Lebedinsky and Stoilo-Lebedinsky deposits.

Open-pit mine is the initial stage of the process chain. Iron ore is mined by open-cast method through blasting, excavation and transportation of the broken ore mass by automobile and railway transport. Accompanied non-metallic mineral raw materials such as sand, chalk, crystalline schists, quartzitic sandstone are mined and shipped by internal railway transport to the customers.

Ore mass mining is preceded by blasting preparation applied for loosening of the rock mass. Blast hole drilling is effected by rockdrilling machines of SBSh type. Blasting is performed through blasthole charges. Ferrous quartzites and rock overburden mining is effected by mechanical shovel excavators EKG-10, EKG-8I, EKG-8US and EKG-6,3US with further loading into railway and automobile transport. Ore mass which is excavated into the automobile transport is subject to further transshipment into the railway transport at the transfer points inside the open-pit mine. Transshipment of rock mass is effected by EKG-10 excavators. Soft overburden is mined by EKG-6,3US excavators. In addition, for soft overburden mining ESh-10/ 60 and ESh-10/70А dragline excavators are applied.

Rock and soft overburden is transported to the dumps by railway transport. Transported rock material is stacked by excavators. Except for excavator mining of soft overburden, hydromechanical transportation of the overburden to the hydraulic dump is applied.

Production of iron ore concentrate with Fe content less than 69,5%
Ferrous quartzites are transported by railway transport to the Beneficiation Plant where primary crushing takes place. Crushed ore is supplied to the Beneficiation Plant by the conveyors and then is placed into the silo bins where from by means of plate feeders it comes to the grinding stage.

Technological feature of the beneficiation complex includes complete autogenous grinding of ferrous quartzites, which excludes well established medium and fine crushing stages out of the ore preparation procedure and enables to reduce significantly capital and operational costs in regard to entire beneficiation process stage. This method provides for the fullest ore-grain release and allows to produce concentrate of the highest quality. Magnetic beneficiation and desliming technologies are applied for concentrate production.

Finished concentrate is supplied to the filtration area by pipeline system where from after dewatering it is transported by conveyor channels to the storage yards either for shipment to the customers or for transportation to the Pellet Plant. The Fe content in the concentrate produced at the beneficiation Plant is less than 69.5%.

Production of iron ore concentrate with Fe content more than 69,5%
Some part of the concentrate produced at the Beneficiation Plant is sent to the additional processing into the Secondary Beneficiation Plant where concentrate with Fe content more than 69.5% and silicon dioxide content up to 3% is produced. High-grade concentrate is produced under the technology of ball regrinding and magnetic beneficiation of the ordinary concentrate. High-grade concentrate produced at the Secondary Beneficiation Plant is transported by the pipeline system either to the Holding’s Oskol Elektrometallurgical Plant (OEMK) or to the filtration area where from after being dewatered it is sent to the Pellet Plant for production of fluxed pellets to be applied in the DRI-process.

Production of Pellets
The Pellet Plant consists of burden preparation workshop, pelletizing areas, four indurating machines of an OK-306 conveyor type, screening (sorting) area, finished products storage and transportation system, auxiliary systems and gas treatment system.

Non-fluxed Pellets
Non-fluxed pellets with Fe content less than 66,5% are produced at the Pellet Plant out of the iron ore concentrate with Fe content less than 69.5% for blast furnace process and are shipped to the outside customers. Non-fluxed pellets production technological cycle includes burden preparation process, green pelletizing with further induration and screening.

Fluxed Pellets
Fluxed pellets with Fe content more than 66.5% are produced at the Pellet Plant out of the iron ore concentrate with Fe content more than 69.5% which become the raw material for production of HBI. Fluxed pellets are transported by tubular belt conveyor
to the HBI Plants 1 and 2. Addition of fluxing components into the feed material providing for stable operation of the HBI Plants is the distinctive feature of the fluxed pellets production process.

Production of hot briquetted iron (HBI)
Production of metallized briquettes is based on the iron direct reduction process which includes interaction of reformed natural gas flows with iron ore pellets at the temperature of about 900°С. Fluxed pellets with Fe content more than 66.5% produced out of the high-grade concentrate are feedstock for HBI
production.

Due to its quality characteristics, HBI surpasses the scrap metal and is used at many steelmaking plants internationally. And yet, contrast to metallic scrap used at the moment as a basic feedstock for steel making in the electric arc furnaces, briquettes are primary feedstock free of nonferrous metals impurities and plastics which significantly deteriorate the steel quality.

HBI Plant 1 is based on HYL-III Technology and consists of shaft reduction furnace, reformed gas generation plant, process gas flow loops, feedstock charging system, briquetting system, product handling and dispatch system, auxiliary and gas-treatment systems. HBI Plant 2 is based on MIDREX Technology. Its arrangement is similar to HBI Plant 1. Both plants produce iron ore briquettes with Fe content not less than 90%. Total production capacity of two plants is 2,400 thousand tons of briquettes per year. Briquettes are shipped to the outside customers by railway transport.