People in the industry who are often exposed to ferroalloy products should have heard of or encountered such problems. Why does pulverization occur in ferrosilicon? How to prevent ferrosilicon from pulverize? The following Anyang Shengchi factory master will give you detailed answers as follows:
Certain components of ferrosilicon, sometimes due to exposure to water or excessive air humidity during storage, and high content of aluminum, calcium and phosphorus impurities, after a certain period of time, it will produce pulverization, and then release a odor and poison. Phosphine (PH3) and hydrogen (ASH3) gas, which may even burn in severe cases.Why does ferrosilicon pulverize?
1. Improper content of aluminum, phosphorus and calcium in ferrosilicon will cause ferrosilicon to pulverize. When the content of aluminum and phosphorus increases to a certain value at the same time, this kind of ferrosilicon is easy to pulverize in the humid air. Some data point out that the phosphorus content in ferrosilicon is less than 0.04% and the aluminum content is less than 3%, which is not easy Produce pulverization.
2. Our factory has made observations and studies on the silicon content of ferrosilicon and the pulverization of ferrosilicon. It is preliminarily believed that the silicon content in ferrosilicon is relatively low (mostly waste products), which is often easy to pulverize.
The reason may be that the temperature of FeSi, FeSi2 and other silicon and iron compounds in ferrosilicon reduces the volume expansion, causing ferrosilicon to pulverize.
The aluminum content of ferrosilicon produces aluminum hydroxide and gas when it meets with water, which is the main reason for ferrosilicon pulverize.
3. The cooling rate after pouring also affects the ferrosilicon pulverize.
The cooling rate of ferrosilicon is fast, the segregation degree of silicon is small, and it is not easy to pulverize;
If the cooling rate is slow and the degree of segregation of silicon is large, it is easy to pulverize. Similarly, the thickness of the ferrosilicon ingot is thicker, which is easy to pulverize, and when it is thinner, it is not easy to pulverize;
1. The thickness of the ferrosilicon ingot is not easy to be too thick to reduce the segregation degree of the silicon content of the ferrosilicon.
2. Strictly control the silicon content of ferrosilicon, not too low. To control the aluminum, phosphorus and calcium content of ferrosilicon, use better raw materials, especially coke with high ash content, to reduce the content of aluminum and phosphorus. In order to reduce the calcium content of ferrosilicon, add lime to the smelting process. .
3. Ferrosilicon should be stored in the warehouse to prevent rain.