company news about Ferrosilicon smelting operations: segregation and pulverization

The temperature of the molten iron coming out of the furnace is usually 300 to 350°C higher than the melting point of ferrosilicon, so the molten iron condenses slowly. During the slow condensation process, pure silicon with a small density floats up, and the dense iron silicide sinks, that is, after condensation In ferrosilicon ingots, the composition is not uniform. The upper layer of the ingot has a higher silicon content and the lower layer of the ingot has a lower silicon content. This phenomenon is called component segregation.

ferrosilicon 75

Practice has proved that the composition segregation of ferrosilicon increases with the increase of casting thickness and the slowdown of cooling rate, and is related to the silicon content of the alloy. For example, the segregation in thick ingots is more serious than that in thin ingots, and the segregation of 75% ferrosilicon is more serious than that of 45% ferrosilicon.

Severe segregation of alloy components will increase the powdering tendency of ferrosilicon. In order to reduce the segregation of components, first, the thickness of the iron ingot should be reduced; second, the molten iron casting temperature should be lowered; third, the cooling rate of the iron ingot should be accelerated. The thickness of 75% ferrosilicon ingots should be less than 100 mm, and the thickness of 45% ferrosilicon ingots should be less than 150 mm.

ferrosilicon powder

After the casting is completed, when the ferrosilicon turns pink, the iron ingot should be removed from the mold and placed in an iron box. Otherwise, the iron ingot will break in the ingot mold, causing difficulty in lifting the iron.