Reducing agent for production of industrial silicon

Abstract

The invention provides a reducing agent for production of industrial silicon, which relates to a reducing agent. The reducing agent comprises, by mass, 0 to 100% of a petroleum coke particle and 0 to 100% of a modified petroleum coke particle, wherein the granularity of both the petroleum coke particle and the modified petroleum coke particle is in a range of 5 to 60 mm. The reducing agent has no less than 76% of dry basis fixed carbon, no more than 1% residual ash, no more than 8% of coarse ash, 10 to 16% of volatile matters and no more than 8% of moisture. Compared with a conventional petroleum coke reducing agent, the reducing agent provided by the invention has the following advantages: permeability of the reducing agent is at least doubled, feeding loss and furnace surface burning loss of petroleum coke are reduced by more than 6%, the degree of graphitization at a temperature of 1300 DEG C is decreased by more than 50%, relative resistivity retention time is prolonged by more than 20 min, reductibility is improved by more than 30%, and a furnace age is almost doubled.

Description

technical field

[0001] The invention relates to a reducing agent, in particular to a reducing agent for industrial silicon production. Background technique

[0002] At present, the main reducing agents used in the smelting of industrial silicon in my country are: petroleum coke, low-ash bituminous coal, charcoal, wood blocks, etc. Charcoal is the most ideal reducing agent. Charcoal has a high porosity of more than 75%, good reactivity, and high resistivity, which is almost 10 times that of any kind of coke, which is conducive to deep electrode insertion. The ash content is about 3%. However, because charcoal is a renewable resource, not only is it expensive to smelt, but also the smelting of industrial silicon by using large charcoal processes will cause great damage to the environment.

[0003] At present, various industrial silicon production enterprises have selected petroleum coke to replace part of charcoal to varying degrees, but in the production process, due to the ...

Examples

Embodiment 1

[0031] A reducing agent for industrial silicon production, consisting of petroleum coke particles with a particle size in the range of 5-60mm.

[0032] In this embodiment, the petroleum coke particles with a particle size in the range of 5-15mm mainly function to participate in the reduction reaction, and the petroleum coke particles with a particle size in the range of 16mm-60mm can sink to the bottom of the furnace due to the large particle size while participating in the reduction reaction , play the role of carbon replenishment at the bottom of the furnace, and at the same time increase the gas permeability of the bottom of the furnace, make the raw materials react completely, increase the yield, reduce the residue at the bottom of the furnace, the bottom of the furnace is not easy to rise, and the furnace life will be extended by about one time.

Embodiment 2

[0034] A reducing agent for industrial silicon production is composed of modified petroleum coke particles with a particle size in the range of 5-60 mm, and the modified petroleum coke particles are obtained by pressing and molding petroleum coke powder.

[0035] In this embodiment, the density of the compressed modified petroleum coke particles is greatly increased, which improves the resistivity of the modified reducing agent, reduces the degree of graphitization in the production process, and further improves the reducing performance. For example, a pressure of 100-300 tons is used for compression molding, and the greater the particle size of the reducing agent, the greater the pressure used.

Embodiment 3

[0037] A reducing agent for industrial silicon production, consisting of modified petroleum coke particles with a particle size in the range of 5-60 mm, the modified petroleum coke particles including petroleum coke powder and SiO 2 Powder composition.

[0038] In this example, the SiO 2 The powder plays the role of increasing the resistance, preferably amorphous SiO 2 powder.

[0039] In this embodiment, the modified petroleum coke particles include 1%-10% SiO by mass percentage 2 powder and the rest of the petroleum coke powder composition, according to the above components weighed SiO 2 The powder and petroleum coke powder are mixed evenly and then pressed to form modified petroleum coke particles. For example, the pressure of 100-300 tons is used for compression molding. The larger the particle size of the reducing agent, the greater the pressure used. The dosage of each component varies according to the size of the modified petroleum coke particles.

[0040] Among th...

technical field

[0001] The invention relates to a reducing agent, in particular to a reducing agent for industrial silicon production. Background technique

[0002] At present, the main reducing agents used in the smelting of industrial silicon in my country are: petroleum coke, low-ash bituminous coal, charcoal, wood blocks, etc. Charcoal is the most ideal reducing agent. Charcoal has a high porosity of more than 75%, good reactivity, and high resistivity, which is almost 10 times that of any kind of coke, which is conducive to deep electrode insertion. The ash content is about 3%. However, because charcoal is a renewable resource, not only is it expensive to smelt, but also the smelting of industrial silicon by using large charcoal processes will cause great damage to the environment.

[0003] At present, various industrial silicon production enterprises have selected petroleum coke to replace part of charcoal to varying degrees, but in the production process, due to the ...

Examples

Embodiment 1

[0031] A reducing agent for industrial silicon production, consisting of petroleum coke particles with a particle size in the range of 5-60mm.

[0032] In this embodiment, the petroleum coke particles with a particle size in the range of 5-15mm mainly function to participate in the reduction reaction, and the petroleum coke particles with a particle size in the range of 16mm-60mm can sink to the bottom of the furnace due to the large particle size while participating in the reduction reaction , play the role of carbon replenishment at the bottom of the furnace, and at the same time increase the gas permeability of the bottom of the furnace, make the raw materials react completely, increase the yield, reduce the residue at the bottom of the furnace, the bottom of the furnace is not easy to rise, and the furnace life will be extended by about one time.

Embodiment 2

[0034] A reducing agent for industrial silicon production is composed of modified petroleum coke particles with a particle size in the range of 5-60 mm, and the modified petroleum coke particles are obtained by pressing and molding petroleum coke powder.

[0035] In this embodiment, the density of the compressed modified petroleum coke particles is greatly increased, which improves the resistivity of the modified reducing agent, reduces the degree of graphitization in the production process, and further improves the reducing performance. For example, a pressure of 100-300 tons is used for compression molding, and the greater the particle size of the reducing agent, the greater the pressure used.

Embodiment 3

[0037] A reducing agent for industrial silicon production, consisting of modified petroleum coke particles with a particle size in the range of 5-60 mm, the modified petroleum coke particles including petroleum coke powder and SiO 2 Powder composition.

[0038] In this example, the SiO 2 The powder plays the role of increasing the resistance, preferably amorphous SiO 2 powder.

[0039] In this embodiment, the modified petroleum coke particles include 1%-10% SiO by mass percentage 2 powder and the rest of the petroleum coke powder composition, according to the above components weighed SiO 2 The powder and petroleum coke powder are mixed evenly and then pressed to form modified petroleum coke particles. For example, the pressure of 100-300 tons is used for compression molding. The larger the particle size of the reducing agent, the greater the pressure used. The dosage of each component varies according to the size of the modified petroleum coke particles.

[0040] Among th...