A Comprehensive Analysis Of The Metal Silicon Powder Production Process: Key Steps From Raw Materials To Finished Product!

High-quality raw materials are the foundation for producing high-quality metal silicon powder. The primary raw materials for producing metal silicon powder are silica stone and carbon-based reducing agents. Silica stone should be selected with a high silica content (typically ≥98%) and low impurity levels, with common types including quartzite and quartzite rock; carbon-based reducing agents are typically petroleum coke, charcoal, or bituminous coal, requiring high fixed carbon content and low ash content. Before entering the production process, raw materials must undergo pretreatment: silica stone is crushed and screened to ensure particle size meets production requirements, typically controlled between 10-50 mm; carbon-based reducing agents are also crushed and screened, followed by drying to remove moisture, preventing interference with heat transfer and chemical reactions in subsequent processes.

Smelting is the core process in the production of silicon powder, typically carried out using an electric arc furnace. Pre-treated silica and carbon-based reducing agents are mixed in a specific ratio and added to the electric arc furnace. Under high temperatures (1800-2000°C), the silica in the silica reacts chemically with the carbon-based reducing agents to produce silicon and carbon monoxide. During the reaction, parameters such as electrode position, current intensity, and raw material feeding rate are controlled to maintain stable temperature and chemical reactions within the furnace. After a period of smelting, the generated silicon accumulates at the bottom of the furnace. Once a sufficient quantity is reached, the molten silicon is discharged and cast into silicon ingots. During the electric arc furnace smelting process, the furnace atmosphere and temperature must be strictly controlled to minimize impurity contamination and enhance the purity of metallic silicon.

The silicon ingots cast from the electric arc furnace must be further processed into powder form. First, a crusher is used to break the silicon ingots into smaller pieces, with the crushed silicon blocks typically ranging in size from 20 to 100 mm. The crushed silicon blocks are then fed into grinding equipment for further processing. Commonly used grinding equipment includes ball mills and Raymond mills. During the grinding process, parameters such as grinding time, type, and quantity of grinding media are controlled to grind the silicon blocks into metal silicon powder of the desired particle size. To obtain metal silicon powder with uniform particle size, the ground material is further screened using a screening device to remove particles that do not meet the particle size requirements. Typically, the particle size range of metal silicon powder is between 80 and 325 mesh.

To meet the purity requirements of metal silicon powder for different industries, the ground metal silicon powder typically undergoes purification treatment. Common purification methods include chemical purification and physical purification. Chemical purification primarily involves removing metallic and non-metallic impurities such as iron, aluminum, and calcium from the metal silicon powder through acid leaching, alkali leaching, and other methods; Physical purification employs methods like magnetic separation and gravity separation, utilizing the physical property differences between impurities and silicon to separate impurities. During the purification process, process parameters must be strictly controlled to ensure that impurities are removed without affecting the performance of the metal silicon powder. Purified metal silicon powder must undergo rigorous quality testing, with testing items including particle size distribution, chemical composition (silicon dioxide content, impurity content, etc.), and physical properties (bulk density, flowability, etc.). Only metal silicon powder that meets all quality standards can be packaged and sold as finished products.

Finished metal silicon powder is typically packaged in sealed containers to prevent moisture absorption, oxidation, or contamination during storage and transportation. Common packaging materials include plastic woven bags and composite paper bags, with packaging specifications determined based on customer requirements, typically 25 kg per bag or 50 kg per bag. Packaged metal silicon powder should be stored in a dry, well-ventilated warehouse, away from moist air and corrosive substances, and kept away from fire sources and heat sources to prevent fires or explosions. During storage, regular spot checks should be conducted on the product to ensure consistent quality.