How to choose between Ferro Silicon 75 and 72

What Is Ferro Silicon

Ferro Silicon is an alloy composed of iron and silicon, produced by melting a mixture of iron and silicon in an electric arc furnace. Its primary components are iron (70%-75%) and silicon (15%-30%), along with trace elements such as carbon, aluminum, and calcium.

Common grades of Ferro Silicon include FeSi65, FeSi70, FeSi72, and FeSi75. This article will focus on 72-grade Ferro Silicon and 75-grade Ferro Silicon, helping readers understand how to make an appropriate choice between these two grades.

Core Differences Between 72-Grade Ferro Silicon and 75-Grade Ferro Silicon

Silicon Content: The Primary Difference

Grade 72 Ferro Silicon has a silicon content ranging from 72% to 80%, slightly lower than Grade 75 Ferro Silicon. This results in slightly weaker deoxidizing and reducing capabilities compared to Grade 75 Ferro Silicon. However, in certain applications where silicon content requirements are not extremely stringent, its performance is more stable, and the cost may be relatively lower.

Grade 75 Ferro Silicon typically has a silicon content between 74% and 80%, with a minimum silicon content of ≥75% in its composition. The higher silicon content gives it stronger deoxidizing and reducing capabilities. When reacting with oxygen in molten steel, it can remove oxygen more quickly and thoroughly, reducing oxide inclusions in the steel and thereby improving steel quality. Additionally, when acting as a reducing agent in reactions, its reaction efficiency is relatively higher.

Physical Properties: Different Characteristics

Grade 72 Ferro Silicon is relatively hard at room temperature and difficult to cut.

Grade 75 Ferro Silicon, on the other hand, has high density, high strength, good ductility, and high toughness, enabling it to withstand various external pressures and exhibit excellent impact resistance and wear resistance.

Cost Considerations: Economic Factors

Due to its higher silicon content and purity, Grade 75 Ferro Silicon typically has a slightly higher cost.

Grade 72 Ferro Silicon, with its slightly lower silicon content, is a more economical choice, suitable for applications where cost sensitivity is a priority.

Impurities and other elements: indicators of quality

Key impurities to monitor include sulfur, phosphorus, and aluminum content. For high-quality steel production, lower impurity levels are preferable.

Grade 75 Ferro Silicon may have stricter impurity limits, making it more suitable for applications requiring higher purity.

Grade 72 Ferro Silicon may have relatively higher impurity levels, but it is acceptable for applications with less stringent impurity requirements.

Application Differences of Ferrosilicon 72 and 75

Grade 72 Ferro Silicon: The Ideal Choice for Specific Applications

Grade 72 Ferro Silicon is commonly used in steelmaking as a deoxidizer and in foundries for cast iron production.

Its slightly lower silicon content makes it cost-effective for large-scale applications without significantly affecting performance.

75-grade Ferro Silicon: A popular choice for high performance

75-grade Ferro Silicon is widely favored for its high silicon content and low impurity levels. It is extensively used in steel production, cast iron production, and as raw material for magnesium production via the Pigeon process.

Its excellent efficiency in steel deoxidation and improving mechanical properties makes it the preferred choice for scenarios with high quality requirements.

How to Choose Between 72-Grade Ferro Silicon and 75-Grade Ferro Silicon

Based on Application Requirements for Silicon Content

If stronger deoxidation performance is required, prioritize 75-grade Ferro Silicon.

For scenarios where silicon content requirements are not extremely stringent, 72-grade Ferro Silicon may be a more suitable choice.

Consider the requirements for impurity levels  

In the production of high-quality steel and special alloys, low-impurity Ferro Silicon is required, in which case 75-grade Ferro Silicon should be prioritized.  

If impurity requirements are not stringent, 72-grade Ferro Silicon can be considered as an alternative option.

Balance cost-effectiveness  

In large-scale production, if performance requirements permit, selecting 72-grade Ferro Silicon is more economical.

When performance requirements are high and the budget permits, 75-grade Ferro Silicon can be selected.  

Combine with actual production testing  

Ultimately, testing and evaluation based on specific production conditions are necessary to determine the most suitable type of Ferro Silicon.  

Conclusion  

The choice between 72-grade and 75-grade Ferro Silicon requires comprehensive consideration of production requirements, product quality standards, costs, and production process adaptability.

If stronger deoxidation and reduction capabilities are required for high-end steel production or scenarios with stringent reduction reaction requirements, grade 75 Ferro Silicon is a better choice; for the foundry industry, general steel production, and cost control, grade 72 Ferro Silicon is more suitable. In actual selection, testing and evaluation should be conducted based on specific production conditions to determine the most suitable type of Ferro Silicon.