Raw Materials For The Production Of Ferrosilicon
The raw materials required for the production of ferrosilicon are quartzite Stone, coke, and steel chips. Quartzite is rich in SiO₂, coke is used as a reducing agent to precipitate Si from SiO₂, and steel scrap promotes the reduction effect and removes the reduced Si from the reaction zone. The raw material requirements for producing different grades of ferrosilicon are different, Low-aluminium ferrosilicon requires chemical testing of the raw material to ensure that low aluminum is present in the raw material, due to its low aluminum content.
Raw Material Requirements For The Production Of Ferrosilicon.
In order to ensure the purity of ferrosilicon, quartz stone, as an important raw material for the production of ferrosilicon, is required to have internal SiO₂ ≥ 97%.SiO₂ is a kind of chemically stable oxide, which needs a higher temperature for reduction, if the SiO₂ content in quartz stone is low, then it will increase the electricity consumption and the amount of reducing agent, which will make the recovery rate decrease and increase the cost of ferrosilicon production. In addition to SiO₂, quartz stone also contains Al₂O3, CaO, and other compounds, which will seriously affect the purity and quality of ferrosilicon, so the quartz stone used for the production of ferrosilicon requirements must have high purity.
Coke is an important reducing agent in ferrosilicon production and is used to reduce silicon in quartzite. Metallurgical coke, petroleum coke, bituminous coke, bituminous coal and charcoal are important carbonaceous reducing agents in the production of ferrosilicon, and the particle size and chemical properties of coke have a large impact on the quality of ferrosilicon. Metallurgical coke is currently the raw material used in large quantities for the production of ferrosilicon. Before being involved in the production of ferrosilicon, coke needs to be calcined at high temperatures in order to minimise internal impurities and ash content. Coke can usually be divided into high-temperature coke and low-temperature coke, low-temperature coke is widely used in the production process of ferrosilicon due to its good chemical activity and high electrical resistance.
Steel chips are the main source of Fe in ferrosilicon. For the production of ferrosilicon, only ordinary carbon steel chips are required to be used, alloy steel chips are prohibited to be used due to the high content of elements within them, which will affect the chemical properties of ferrosilicon, and pig iron chips are prohibited to be used for the production of ferrosilicon because they will make the phosphorus content of ferrosilicon increase. In addition, rusty steel chips are prohibited to be used in the production of ferrosilicon due to its high impurity, which makes it impossible to accurately control the Fe content when smelting ferrosilicon. The length of the steel chips should not be too long in order to prevent the uneven mixing of materials and the resulting blockage of the downcomer pipe, and the length of the steel chips should be controlled within 100mm in general.