Black Silicon Carbide Deoxidizer is a high-performance composite deoxidizer developed by AON METALS specifically for the steel and foundry industries. It uses high-quality silicon carbide (SiC) as its main component and is produced through a high-temperature synthesis process, exhibiting high hardness, high refractoriness, and good chemical stability.

Its dual function in the metallurgical process:

Unlike single silicon powder or carbon powder, black silicon carbide is a composite deoxidizer. It utilizes the dual deoxidizing capabilities of silicon and carbon in silicon carbide, working synergistically:

Enhanced Deoxidation: Silicon combines with oxygen to form SiO₂, and carbon combines with oxygen to form CO. Both work together to reduce dissolved oxygen in molten steel, resulting in faster and more thorough deoxidation.

Increased Silicon and Carbon: Some silicon carbide decomposes at high temperatures, and the silicon and carbon are absorbed by the molten steel, achieving alloying of the steel and partially replacing ferrosilicon and carburizing agents.

Thermodynamic Advantages: The deoxidation reaction of silicon carbide is a strongly exothermic reaction, which helps to increase the temperature of the molten steel, promotes the flotation of inclusions, and purifies the molten steel.

Deoxidizer Black Silicon Carbide

chemical composition

Grade	Chemical Composition				Size (customizable)	Recommended Application Scenarios and Advantages
	SiC	Free C	Fe₂O₃	Al₂O₃
SiC 98	≥98.0	≤0.2	≤0.6	-	0-1mm, 0-10mm	High-quality special steel and alloy steel: Requires extremely low inclusions and precise carbon and silicon enrichment.
SiC 97	≥97.0	≤0.3	≤1.2	-	1-10mm	Key structural steel and pipeline steel: Balances performance and cost, with excellent deoxidation effect.
SiC 90	≥90.0	≤1.0	≤1.2	-	1-10mm, 10-50mm	Ordinary carbon steel and low-alloy steel: A highly cost-effective deoxidizer and exothermic agent.
SiC 88	≥88.0	≤4.0	≤1.5	-	10-50mm	Foundry hot metal pretreatment: Increases silicon and carbon, raises temperature, and improves graphite morphology.
SiC 球团	≥70.0	-	≤3.0	≤5.0	10-50mm	Converter or electric furnace additive: Reduces dust, stabilizes yield, and facilitates metering.

Deoxidation principle

During the steelmaking process, when black SiC is added to the surface of the slag layer, the FeO content in the slag decreases, destroying the dissolution balance of oxygen in the slag and molten steel. In order to maintain the distribution constant, the oxygen in the steel will diffuse into the slag, thereby reducing the oxygen content in the steel and achieving the purpose of deoxidizing the molten steel. At the same time, part of the silicon carbide decomposes into Si and C and enters the molten steel, which plays a role in increasing silicon and carbon.

Application advantages

AON's black silicon carbide deoxidizer has demonstrated its superior performance in actual production at multiple steel mills and foundries. Here is a summary of our experience:

1. Improved Deoxidation Efficiency

Principle Verification:

The Si-C bonds in silicon carbide break at high temperatures, generating highly active [Si] and [C], resulting in superior deoxidation capabilities compared to adding ferrosilicon or carbon powder alone.

Empirical Data:

In the smelting of Q235B steel in a 120-ton converter, using SiC 90 particles to replace part of the ferrosilicon and recarburizer reduced the final oxygen activity by 15-20 ppm and shortened the deoxidation time by 2-3 minutes, effectively improving converter operating rates.

2. Reduced Overall Costs

Alternative Solution:

1 ton of SiC 90 (SiC≥90%) can replace approximately 0.8-0.9 tons of 75% ferrosilicon and 0.2-0.3 tons of recarburizer in terms of alloying contribution.

Cost Calculation:

Based on current market prices, using a silicon carbide deoxidation scheme can reduce the deoxidation and alloying cost per ton of steel by approximately 15-25%. The specific savings depend on raw material price fluctuations and the addition process.

3. Significant Environmental Benefits

Reduced Auxiliary Material Consumption:

Since the deoxidation products are SiO₂ and CO, their reaction characteristics help reduce slag viscosity, thereby reducing the amount of fluorite and other thinning slag agents used, with a reduction of up to 10-20%.

Cleaner Production:

Compared to injected carbon powder, using appropriately sized silicon carbide particles or pellets significantly reduces dust generation, improving the workshop operating environment.

4. Improved Steel Quality

Heating Effect:

The oxidation reaction of SiC (SiC + 2[O] → SiO₂ + CO↑) is a strongly exothermic reaction. Theoretical calculations show that adding 1 kg/t of SiC can raise the temperature of the molten steel by approximately 8-10°C, making it particularly suitable for conditions with low tapping temperatures.

Improved purity:

The deoxidation products are low-melting-point silicates, which are easy to polymerize and float to the surface for removal, helping to reduce the total amount of inclusions in steel and improve the mechanical properties and fatigue life of steel.

Deoxidizer Black Silicon Carbide

Application field

Steelmaking industry:

It is widely used in the smelting and deoxidation process of ordinary steel, alloy steel and special steel. It is a commonly used deoxidation material in the reduction period of electric furnace steelmaking and refining furnace.

Foundry industry:

In cast iron production, it can be used as an inoculant to promote graphitization, improve the microstructure of cast iron, and improve the quality and performance of castings.

FAQ

Q1: Which is better for deoxidation, black silicon carbide or ferrosilicon powder?

A1: Both have their advantages. Black silicon carbide is a composite deoxidizer, providing deoxidation and alloying effects for both silicon and carbon. The reaction is exothermic, giving it a significant advantage in overall cost and heating effect. Ferrosilicon powder is a single deoxidizer with stable composition, suitable for precise adjustment of silicon content. In practical applications, they are often used together, for example, using silicon carbide for initial rapid deoxidation and heating, followed by a small amount of ferrosilicon for final deoxidation and fine-tuning of composition.

Q2: How should black silicon carbide be stored? Will it become ineffective due to moisture?

A2: Black silicon carbide is chemically stable and will not react violently with water like metallic calcium or magnesium. However, as a fine particle or powder, it will absorb moisture when exposed to a humid environment for a long time, which may cause slight splashing when added and affect the yield. It is recommended to store it in a dry, ventilated warehouse, stacked on pallets, avoiding direct contact with the ground. Our products are packaged in ton bags with an inner moisture-proof film, effectively preventing moisture damage during transportation and short-term storage.

Q3: Can you provide samples for testing?

A3: Of course. As the source factory, we support providing potential customers with 1-5 kg of free samples (you only need to pay for shipping) for small-scale furnace testing or laboratory analysis. Please contact us to inform us of your specific grade and particle size requirements.

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