ferro silicon 65
Improper aluminum, phosphorus and calcium content in ferrosilicon will all contribute to powdering of ferrosilicon. When the aluminum and phosphorus contents increase to a certain value at the same time, this ferrosilicon is prone to powdering in air with high humidity. Some data point out that the phosphorus content in ferrosilicon is less than 0.04% and the aluminum content is less than 3%, so it is not easy to cause powdering.
ferro silicon 72
Some units have observed and studied the silicon content of ferrosilicon and the powdering phenomenon of ferrosilicon. It is initially believed that ferrosilicon has a low silicon content (mostly waste products) and is often easily powdered. The reason may be that the temperature of FeSi, FeSi2 and other silicon and iron compounds in ferrosilicon decreases and the volume expands, causing ferrosilicon to powder. Ferrosilicon containing aluminum forms aluminum hydroxide and generates gas when it meets water, which is the main reason for the powdering of ferrosilicon.
ferrosilicon powder
The cooling rate after pouring also affects the powdering of ferrosilicon. The cooling speed of ferrosilicon is fast and the segregation degree of silicon is small, so it is difficult to pulverize; the cooling speed is slow and the segregation degree of silicon is large, pulverization is easy to occur. By the same token, thicker ferrosilicon ingots are prone to pulverization, while thinner ones are less likely to pulverize.
In order to prevent ferrosilicon powdering, the following three points should be noted:
1. The thickness of the ferrosilicon ingot should not be too thick to reduce the degree of segregation of the silicon content in the ferrosilicon.
2. Strictly control the silicon content of ferrosilicon, not too low. Control the aluminum, phosphorus and calcium content of ferrosilicon. For this purpose, better raw materials must be used, especially high-ash coke cannot be used to reduce the aluminum and phosphorus content. In order to reduce the calcium content of ferrosilicon, the addition of lime should be minimized during smelting.
