Lime-based additive for steel smelting and the preparation method thereof

A preparation method of lime-based additive for steel smelting, which includes raw material crushing and mixing, to manufacture the powdery additive, wherein:

• (1) the raw materials include a lime-based material and a carbonaceous material, the content of lime-based material is 40-80 wt % relative to the total amount of the raw materials, and the remaining is the carbonaceous material;
• the lime-based material is a passivated CaO powder with a low flowability, or the mixture of the passivated CaO powder and CaCO3 powder, and the carbonaceous material is at least one of coke, graphite, semi-coke powder and coal with carbon content not less than 85 wt %;
• and
• (2) the raw materials are crushed into particles having a plurality of edges or being dendritic, with a particle size of 0.0005-1.0 mm.

A preparation method of lime-based additive for steel smelting, which includes raw material crushing, mixing and pressing, to manufacture the pellet additive, wherein:

• (1) the raw materials include a lime-based material, carbonaceous material and agglomerant, relative to the total amount of the raw materials, the content of lime-based material is 40-80 wt %, the content of the agglomerant is 1-5 wt %, and the remaining is the carbonaceous material, the lime-based material is a passivated CaO with a low flowability, or the mixture of the passivated CaO powder and CaCO3 powder, the carbonaceous material is at least one of the coke, graphite, semi-coke powder and coal with carbon content not less than 85 wt %, and the agglomerant has a microstructure of strip, streak or dendritic, and is at least one of MgO, Al2O3, and CaCO3;
• (2) the raw materials are crushed into particles having a plurality of edges or being dendritic, with a particle size of 0.0005-1.0 mm;
• and
• (3) the particle size of the pellet is 10 mm-60 mm.