1) Grade and purity of raw materials: Smelting requires raw materials to be of the highest possible grade. Raw materials with high purity can achieve high yield and low consumption.
2) Harmful impurities in raw materials: The impurities in raw materials are harmful such as sulfur and phosphorus, because after they enter the ferrochromium alloy, they will affect the quality of steel and steel products.
3) Particle size of raw materials: Whether the particle size of raw materials is suitable has a great impact on the smelting process. Excessive grain size of the raw material will make it difficult to melt, cause difficulty in recovery, increase the electrical conductivity, increase the amount of slag, worsen the furnace condition, and deteriorate various technical and economic indicators of smelting. However, if the particle size of the raw material is too small and there is too much powder, the air permeability of the charge will be poor and the pressure around the electrode will be high, causing ignition.
Moreover, the powder material is easy to melt, which will cause the upper furnace section to sinter and suspend the material, leading to material collapse. The result is unstable electrodes, frequent ignition and material collapse, and unreduced raw materials directly entering the crucible, which will also deteriorate the technical and economic indicators. Therefore, there should be strict requirements on the particle size of raw materials for submerged arc furnaces.
