PROJECT FOR THE RECOVERY OF REFINING SLAG (WHITE SLAG) AS A SUBSIDIARY MATERIAL IN THE EAF CASTING PROCESS.
The plant was developed with the specific intention of internally reusing a flow of inert material, produced continuously during the production process, which has chemical-physical characteristics suitable for its re-introduction into the industrial cycle of the plant, replacing first (so-called “dark”). Specifically, a product treatment and preparation is carried out of the residue that originates from the refining phase of the steel in the ladle (white slag) and which has a high residual content of calcium oxide, to obtain a flux product of suitable size to be blown into the EAF melting furnace, in partial replacement of the raw material of calcareous origin, with the aim of facilitating the formation of foamy slag, improving the energy efficiency of the furnace and reducing the consumption of refractories.
The introduction of this process, which adds to the operations already typically performed in the iron and steel process for environmental purposes, has a strong innovative value and allows to bring further important benefits to many environmental factors affected by the activities carried out in the Beltrame plant. The first tests have provided very promising results, leading to hypothesize a percentage of internal reuse of white slag of around 35-40% of the total annual production. The positive impact in limiting land use will be quantifiable when fully operational in a reduction of around 10,000 tonnes per year in the extraction of raw materials (primary environmental impact) and a decrease in volumes sent to landfills of around 15,000 m3 (environmental impact secondary). This lesser land use will also manifest itself in the landscape indirectly linked to mining and waste planting activities. A similar benefit can be obtained in the field of logistics and air pollution, with a reduction in the flow of vehicles quantifiable at around 1000 vehicles/year, corresponding to a decrease in emissions of fine particles and secondary pollutants along the routes traveled by the vehicles.