Ferro Silicon Fast Cooling Speed And Low Segregation Of Silicon
Smelting Ferro Silicon is generally used in mine furnace, which is produced by continuous operation method.
The so-called continuous operation method, is with the burden of heat after the continuous reaction and melting, so that the material surface corresponding decline; The amount of alloy accumulated in the furnace is periodically released. During the whole smelting process, the electrode is inserted deep inside the burden and does not reveal the arc, so the heat loss is less and the furnace temperature is high.
Because of these characteristics of Ferro Silicon smelting, the whole smelting process is not staged, this method is called continuous operation method.
In addition, it is also useful for smelting Ferro Silicon with blast furnaces. However, because of its low temperature, the product silicon content is about 10~20﹪, now generally do not use blast furnace smelting Ferro Silicon.
Some components of Ferro Silicon, sometimes due to the storage period of water or air humidity too large, at the same time, aluminum, calcium and phosphorus impurity content is high, after a certain period of time, will produce the phenomenon of powdering, and then emit a smelly, toxic phosphine ﹙ph3﹚ and hydrogen ﹙ash3﹚ gas, serious and even may occur combustion phenomenon.
The improper content of aluminum, phosphorus and calcium in Ferro Silicon will contribute to the. When the content of aluminum and phosphorus increases to a certain value, this kind of Ferro Silicon easily produces powdering in the humid air. Some data indicate that the phosphorus content in Ferro Silicon is less than 0.04 ﹪, and the aluminum content is less than 3 ﹪, which is not easy to produce powdering phenomenon.
Some units have observed and studied the phenomenon of Ferro Silicon's powdering by Silicon content. It is believed that the low silicon content in Ferro Silicon is often easily powdering. The reason is that the temperature of silicon and iron in Ferro Silicon, such as FeSi and FESI2, may reduce the volume expansion, which will result in the powdering of Ferro Silicon. The main cause of Ferro Silicon powdering is the formation of aluminum hydroxide and gas after water with Al content.
The cooling rate after pouring has an effect on the Ferro Silicon powder. The cooling rate of Ferro Silicon is fast, the segregation degree of silicon is small, it is not easy to produce powdering, the cooling speed is slow, the segregation of silicon is larger, it is easy to produce powdering. In the same way, the thickness of Ferro Silicon ingot is thicker, it is easy to produce powdering, and it is not easy to produce powdering when thinner.