Microsilica: A Versatile Additive with Diverse Applications

Microsilica, also known as silica fume, is a highly reactive pozzolanic material that finds applications in various industries, including construction, cement, and refractory materials. It is a byproduct of the production of silicon metal and ferrosilicon alloys.

Khorshid Alyazh: A Leading Producer of Microsilica

Among the prominent producers of μ-SiO2 is Khorshid Alyazh, a Qazvin-based company in Iran. With state-of-the-art facilities and a dedicated team of experts, Khorshid Alyazh has established itself as a reliable supplier of high-quality μ-SiO2 globally.

Production Process

Microsilica is produced as a byproduct of the electric arc furnace process used in the production of silicon metal and ferrosilicon alloys. The process can be summarized as follows:

  • Raw Materials: Khorshid Alyazh sources high-grade quartz and coal to produce silicon metal and ferrosilicon alloys.
  • Electric Arc Furnace: The raw materials are charged into an electric arc furnace, where an electric arc creates intense heat.
  • Reduction: The intense heat causes the quartz to reduce and combine with the carbon from the coal to form silicon metal or ferrosilicon alloys.
  • μ-SiO2 Formation: During the reduction process, a significant amount of silicon monoxide (SiO) gas is produced. This gas is oxidized to form μ-SiO2 particles, which are collected using baghouses or cyclones.
  • Collection and Packaging: The collected μ-SiO2 particles are packaged in bulk bags or other suitable containers for distribution.

Product Specifications

Khorshid Alyazh produces microsilica in accordance with international standards, including ASTM C1240 and EN 13263-1. The typical specifications of its products include:

  • SiO2 Content: >90%
  • Specific Surface Area: >20 m2/g
  • Bulk Density: 250-350 kg/m3
  • Loss on Ignition: <5%
  • Moisture Content: <1%


Microsilica is primarily used as an additive in the following applications:

  • Concrete: Microsilica enhances the strength, durability, and abrasion resistance of concrete. It is used in high-performance concrete, self-compacting concrete, and other specialized concrete applications.
  • Cement: Microsilica is added to cement to improve its strength and reduce its permeability. It is used in the production of blended cements and high-performance cements.
  • Refractory Materials: Microsilica is used in the production of refractory bricks and mortars, which are used in high-temperature applications, such as furnaces and kilns.
  • Other Applications: Microsilica also finds applications in the production of ceramics, paints, and coatings.

Competitive Advantages

Khorshid Alyazh has established a competitive edge in the microsilica market through:

  • High Quality Standards: Stringent quality control measures ensure the consistency and reliability of its products.
  • Technical Expertise: The company’s team of experienced engineers and metallurgists provides technical support and customized solutions to its customers.
  • Global Reach: Khorshid Alyazh exports its products to over 20 countries worldwide, including the US, Europe, and Asia.
  • Customer Focus: The company prioritizes customer satisfaction and strives to meet their specific requirements through tailored solutions.

In conclusion, microsilica is a versatile additive with diverse applications in various industries. Khorshid Alyazh plays a significant role in meeting the global demand for this material through its commitment to quality, technical expertise, and customer focus. The company has earned a reputation as a reliable and innovative supplier in the microsilica industry.


Khorshid Alyazh


Sio2 Min.85%
Fe2O3 Max 2%
CaO Max 1.5%
Al2O3 Max 1%
MgO Max 1/5%
C Max 3%
L.O.I Max 3/55%
Humidity Max 1%