The smelting process of silicon

Chemical silicon is the production of silicone and polysilicon for silicon metal. From a global perspective, the consumption of metallurgical silicon almost use in chemical silicon consumption, but with the continuous development of science and technology, the chemistry of silicon used in the field of organic silicon and semiconductor production is continue to broaden, and is widely used in the production of organosilicon monomer and polymer silicone oil, silicone rubber, silicone resin buildings corrosion, waterproofing agents, they have a high temperature, electrically best edge, resistance to radiation, water and other unique properties. Electrical, aerospace, machinery, chemicals, pharmaceuticals, defense, construction section. More than 95% of the integrated circuit core is made of semiconductor silicon, semiconductor is a pillar of the contemporary information industry. "Information superhighway" in a large number of applications in the fiber-optic cable fiber optics, silicon metal for the production of raw materials. Chemistry of silicon widely used as a high-tech fields, and an important basic industries, consumption growth is stabilizing.

The metal powder supplier use quartz rock as raw materials, low-ash carbonaceous material as reductant to produce chemical metal silicon. Electric furnace produce chemical silicon, the raw materials mainly silica and carbon materials. Carbon raw material again petroleum coke quality anthracite or charcoal, can also be mixed with a part, to increase the charge resistance. Raw materials require necessary purity, good response, in order to achieve the product specifications; reducing agent has a different reaction, in order to have an adequate response with quartz; furnace burden with different ingredients, and with different granularity, in order to through the adequate coordination make the electric furnace with good effect.

The process of silicon oxide mineral smelting metallic silicon is a no slag process, chemical silicon smelting is through stringent choice of silica, not only the content of impurities is less, but also requires a high mechanical strength, and sufficient thermal stability, a suitable particle size composition. Chemical silicon smelting is better to choose silica. The natural form of silicon oxide or exist in independent quartz minerals, or is almost wholly into the rock by the silicon oxide product - silica, or silica morphology sandstone. Production of chemical silicon containing impurities in the silicon oxide mineral and adhesive material in the smelting process and some completely restored, and some parts are restored, some compound form entering the product silicon or born slag. This is not only increases energy consumption, lower product quality, cause difficulties to the smelting process.

Silica into the furnace is required to have a certain particle size. Silica particle size is an important process of smelting. Silica suitable particle size affected by silica types, furnace capacity, maneuvering conditions, as well as the reducing agent and the particle size and other factors, it is determined to the specific conditions of smelting. Carbonaceous reducing agent, the main reducing agent of chemical silicon smelting, petroleum coke, bituminous coal, charcoal. In order to increase the burden of the resistivity and increase the chemical activity, also with gas coal, silica naphthalene, blue, charcoal, semi-coke, low temperature coke, pieces of wood. In the chemical components of the carbonaceous reducing agent, mainly should be considered fixed carbon, ash, volatile matter and moisture. General requirements for fixed carbon, reduce the reductant total required, thus less ash into the impurities, a corresponding reduction in the amount of slag, reduced power consumption, reduced chemical silicon impurity content. The resistivity of the carbonaceous reducing agent to be large, the porosity to be high. The furnace burden resistivity depends primarily on the carbonaceous reductant. The higher carbonaceous reductant resistivity, the better chemical activity, and the high recovery rate of the silicon power.

Source:http://www.mhcmp.com