Silicon Metal Factory

Silicon metal (also known as industrial silicon) is an important industrial raw material, widely used in metallurgy, chemical industry, electronics and photovoltaics. Silicon metal factory produce various models of Silicon. The common metal silicon includes many models. Metallurgical Grade Silicon (MG-Si), commonly with 98% or higher purity such as Silicon Metal 553. Chemical Grade Silicon (Usually 99% and higher purity, such as Silicon Metal 411). Electronic Grade Silicon (EG-Si). Solar Grade Silicon (SoG-Si, 99.9999% or higher purity) and Ultra-High Purity Silicon. Each grade has specific purity levels. Those grades have various applications ranging from metallurgy and chemicals to electronics and solar energy.

Silicon metal production methods mainly include carbon thermal reduction, silica reduction, electrolysis, etc. Among them, carbon thermal reduction is the most common production method in silicon metal factory. In addition, the chemical vapour deposition method and zone melting method are often used in high-purity silicon metal.

The production principle of metallic silicon is mainly to reduce silicon dioxide with carbon reducing agent at high temperature to generate metallic silicon and carbon monoxide. The main equipment required to build a silicon metal factory includes: electric arc furnace, which is the core equipment of silicon metal production, used for high temperature reduction reaction. Raw material processing equipment: such as crusher, screening machine, etc., used for raw material pretreatment. Dust removal and waste gas treatment equipment, used to treat dust and waste gas in production to reduce pollution. Finally, casting equipment is also necessary to cast molten metal silicon.

The production process of Silicon metal includes several steps. Such as raw material preparation, reduction reaction, refining and casting, and waste gas treatment. The specific operation is as follows:

First, prepare the raw materials: quartz sand (SiO2): as the main raw material, providing silicon elements in the production process. Carbon reducing agent (such as petroleum coke, charcoal, etc.) can reduce silicon dioxide. Use auxiliary raw materials (such as iron filings, sawdust, etc.) to adjust the reaction process and improve product quality.

Then, in the electric arc furnace, mix quartz sand and carbon reducing agent in a certain proportion. Heat the materials to a high temperature of 1800-2000°C. At high temperature, silicon dioxide reacts with carbon to produce metallic silicon and carbon monoxide (CO). The main chemical reactions are as follows: SiO2+2C→Si+2COSiO2​+2C→Si+2CO

Reaction process. Heating: The electric arc furnace generates a high-temperature arc through the electrode, raising the temperature in the furnace to 1800-2000°C required for the reaction. Reduction: At high temperature, silicon dioxide reacts with carbon to produce metallic silicon and carbon monoxide gas. Separation: while metallic silicon is deposites at the bottom of the furnace in a molten state, discharge carbon monoxide gas from the top of the furnace.

Finally, it is refining and casting. Refining: Molten metal silicon contains a small amount of impurities (such as iron, aluminium, calcium, etc.), which need us to remove them through the refining process. Common refining methods include oxidation refining, chlorination refining, etc. Casting: The refined metal silicon melt is cast into silicon ingots or silicon particles through casting equipment for subsequent processing and transportation. Usually, the particle size of metal silicon is 10-100mm, also known as standard silicon metal lumps.

China’s metal silicon industry occupies an important position in the world. China has quartz sand mines in many provinces across the country, providing abundant production raw materials for Silicon metal factories. At the same time, there are abundant hydropower resources in the western region, and abundant thermal power, wind power and solar energy resources in the northern region, which can provide cheap electricity resources for silicon metal factories. Therefore, China has become the world’s largest producer of metal silicon, accounting for more than 70% of the global output. In addition to meeting domestic demand, China also exports a large amount of metal silicon to countries and regions such as Japan, South Korea, Southeast Asia, and the United States.