1. The Raw Materials of Ferro Silicon 75
The production of Ferro Silicon 75 begins with a combination of silica, iron sources and a reducing agent. Silica provides the silicon content, iron-bearing materials such as scrap steel or iron oxide supply the metallic base, and carbon materials act as the reducing agent that converts silica into silicon. Wood chips or similar materials are added to improve the permeability of the furnace charge. The quality of these inputs determines both the silicon yield and the impurity profile of the final alloy.
| Material | Role in Production |
|---|---|
| Silica (SiO2) | Primary silicon source |
| Iron-bearing materials | Provide the iron portion of the alloy |
| Carbon (coke, charcoal) | Reduces silica at high temperature |
| Wood chips or similar | Improve furnace permeability |
2. The Submerged Arc Furnace Reaction
Ferro Silicon 75 is produced in a submerged arc furnace operating at extremely high temperature. The core reaction is the reduction of silica by carbon: silicon monoxide gas and molten silicon are produced, the silicon dissolves into molten iron to form the alloy, and slag forms on top and is removed periodically. This continuous process requires stable heat input and consistent raw materials to achieve a reliable silicon level around the 75% range.
3. Refining After Tapping
Once the molten alloy leaves the furnace, it still contains minor impurities and dissolved gases. Refining stabilizes the composition and improves the cleanliness of the alloy. Typical refining steps include settling to remove slag inclusions, skimming surface layers, and adjusting carbon or aluminum residues through controlled cooling. The cleaner the melt, the more stable the final size and impurity profile of the product.
4. Crushing and Sizing
After cooling, the solid alloy forms large blocks, which are crushed and screened into commercial size ranges including the widely used 10–50 mm fraction. Uniform size ensures predictable melting behavior, lower fines content reduces dust and improves handling, and screening allows suppliers to offer custom ranges when needed. A well-controlled crushing process keeps the alloy consistent in steelmaking service.
5. Impurity Control
Impurities such as aluminum, calcium, carbon, sulfur and phosphorus originate from raw materials and the furnace environment. Their levels influence melting speed, deoxidation efficiency and steel cleanliness. Even though Ferro Silicon 75 is defined by its silicon percentage, the impurity profile often determines how smoothly it performs in the furnace or ladle; high-stability batches help steel plants maintain predictable alloy recovery and quality.
6. FAQ
Q1: What raw materials are used to produce Ferro Silicon 75? Silica as the silicon source, iron-bearing materials for the iron portion, carbon materials such as coke or charcoal as reducing agents, and wood chips for furnace permeability.
Q2: What happens inside the electric arc furnace? Silica is reduced by carbon at high temperature, producing silicon that dissolves into molten iron; slag forms on top and is removed periodically.
Q3: Why is refining important after tapping? Refining removes slag inclusions and dissolved gases, stabilizes composition and improves the cleanliness of the alloy.
Q4: How is the 10–50 mm size produced? The cooled alloy blocks are crushed and screened into commercial size ranges, including the 10–50 mm fraction.
Q5: Why does impurity control matter? Aluminum, calcium, carbon, sulfur and phosphorus affect melting speed, deoxidation efficiency and steel cleanliness, so their control determines how predictably the alloy performs.
