PAO Severstal, one of the world's leading vertically integrated steel and mining companies, has completed the construction of environmental facilities as part of the blast furnace # 3 (DP-3) reconstruction project.
According to the CEO of the division “ Severstal Russian Steel ”and resource assets of Evgeny Vinogradov's company, the DP-3 reconstruction project provides for maximum environmental friendliness of pig iron production along the entire technological chain and sources using the best available technologies. The main object of the dust and gas collection system is the aspiration system and gas cleaning. The aspiration system provides for air cleaning from dust from workplaces and technological operations. Gas cleaning, in turn, provides for the purification of blast furnace gas.
The main technological operations, during which the release of pollutants into the atmospheric air from the DP-3 complex, is the preparation and metering of charge materials, loading the charge into blast furnaces, and the operation of the foundry yard. Through the shelters of places of dust and gas formation, the aspiration suction system with control and shut-off valves takes in polluted air and gas for cleaning.
The aspiration valves are controlled automatically. The process is organized from the places of discharge of cast iron and slag, skimmer, side suction from the tap-holes of the isonts above the tap-holes. Since the release of smelting products is carried out simultaneously from only one tap hole, suction from other tap holes is cut off. The operating mode of the valves is synchronized with the operating mode of the foundry equipment.
To prevent emissions of pollutants into the atmosphere when loading material into the furnace (through a non-tasting charging device), emissions from the charging device are suppressed by compressed nitrogen, with the help of which dirty blast furnace gas is blown under the top ovens. Dusty air from the intake chamber of the bell-less loader will be directed to the collector of the new Central Exhaust Station (CVS).
The dust will be removed from the aspiration air by bag filters. The filter consists of 1056 sleeves, 10 m each. The bag filters of the supplier are characterized by their compactness, a larger filtration area, so they can work effectively in confined spaces. Residual dustiness of the air - no more than 8 mg /m3. The discharge will be carried out through a chimney 80 m high. The total cost of the aspiration system project is 850 million rubles, which is 2.5% of the total cost of the DP-3 reconstruction project.
Blast furnace gas cleaning involves dry cleaning and wet cleaning in two stage. The cleaning efficiency is 99.99%. It is organized using dry cleaning of blast furnace gas in a cyclone-type dust collector and a scrubber with an adjustable gap and a drop separator technology from Paul Wurth. The dust captured in the dust collectors is sent for disposal to the sinter plant. Before the dust collectors are unloaded to prevent dusting, the dust is humidified.
Blast furnace gas is the fuel for the air heaters that provide the blast furnace with heated blast. The cost of construction of a gas treatment plant in accordance with the project is 1,083 million rubles, which is 3.3% of the total cost of the reconstruction project.
Industrial water supply of the facilities of the DP-3 complex is performed in a closed circuit of recycling water supply. With the commissioning of the DP-3 facilities, the consumption of household and storm wastewater entering the systems of household and industrial storm sewage does not increase. There are no direct discharges into the water body from the DP-3 complex.
The project provides for a rational waste management scheme. Almost all waste is transferred for disposal in its own production (99.99%), the rest is transferred to its own waste disposal facility - the industrial waste landfill of PJSC Severstal.