Silicon slag is a by-product of metallic silicon smelting, Silicon slag is the waste slag produced in the smelting of metallic silicon (industrial silicon) , and high silicon and high carbon are its core characteristics. The main components are silicon dioxide (SiO₂) and carbon (C), and contain a small amount of metal impurities. Silicon slag is mainly used as a steelmaking deoxidizer in the steel industry.
Chemical content and specifications of silicon slag
| Grade | Si(%) | C(%) | S(%) | P(%) |
| Silicon slag 45 | 45 | 4.0 | 0.1 | 0.05 |
| Silicon slag 50 | 50 | 4.0 | 0.1 | 0.05 |
| Silicon slag 60 | 60 | 4.0 | 0.1 | 0.05 |
| Silicon slag 65 | 65 | 4.0 | 0.1 | 0.05 |
Can silicon slag be used to replace metallic silicon?
The answer is no. Silicon slag cannot directly replace metallic silicon. The reasons are as follows:
A foundry tried to use silicon slag to replace 30% of metallic silicon to produce aluminum alloy. As a result, due to the high carbon content of silicon slag, porosity defects appeared in the castings and the yield rate dropped by 18%.
So what are the main application areas of silicon slag? Please continue reading
Application of silicon slag
| Application areas | Specific use | Advantages |
| Metallurgical industry | Steelmaking deoxidizer, alloy additive | Replace part of ferrosilicon to reduce costs |
| Chemical industry | Raw materials for the production of silicon carbide (SiC) | Taking advantage of high silicon and high carbon characteristics |
| building materials | Processed into microsilica powder (for high performance concrete) | Enhance concrete strength and good impermeability |
| Environmental protection field | Wastewater Treatment Adsorbents | Porous structure to adsorb heavy metal ions |
Characteristics of silicon slag
- High carbon content: Due to the excessive amount of coke required for smelting, the residual carbon combines with silicon oxide.
- Porous structure: After cooling, loose particles are formed, which are easy to absorb moisture.
- Potential self-ignition: Carbon may slowly oxidize when in contact with air, generate heat and even self-ignite when piled up.
- Silicon slag can replace ferrosilicon and save production costs.
- Silicon slag As a deoxidizer in the steelmaking process.
Silicon slag production process
Silicon slag is the waste residue left after the production of metallic silicon. In the process of metallic silicon production, some raw materials such as silica, petroleum coke, etc. are thrown into the smelting furnace together to react and generate metallic silicon, while those impurities and unreacted substances form silicon slag. These silicon slags will be made into silicon slag particles, silicon slag blocks and silicon slag balls according to the different particle size contents required by customers.
What is the price of silicon slag ?
Silicon slag can replace ferrosilicon. The price of silicon slag is much cheaper than ferrosilicon. When manufacturers produce some products that do not require very high hardness, they can buy silicon slag to replace ferrosilicon, which will greatly reduce costs and improve benefits.
The specific price of silicon slag in the Chinese market is generally US$500 per ton in Tianjin. Of course, the specific price depends on the silicon content and iron content.
Why choose silicon slag from Zhenxin Metallurgy
1. Free samples (about 1 kg). Buyers are required to pay for postage
2. Factory direct sales, competitive prices.
3. Credibility guaranteed. Zhenxin Metallurgy has rich export experience and its products have passed SGS testing
4. Fast delivery. Generally, production can be completed in 7-15 days ;
5. Various payment methods. T/T, /C are acceptable