Method for preparing high-purity silicon by energy-saving and environmental protection technology

Abstract

A method for preparing high-purity silicon by an energy-saving and environmental protection technology comprises the following steps: uniformly mixing quartz sand or white carbon black and a reducing agent according to the weight ratio of (0.8-1.2): (1.2-1.6) to obtain a mixture, putting the mixture into a heating furnace with furnace chamber volume being 10-30 liters; spraying carbon powder of 100-325 meshes onto the surface of the mixture with the mass ratio of the carbon power to the mixture being (0.1-0.5): (2.0-2.8); heating the furnace chamber of the heating furnace to 200-260 DEG C for 0.5-1 h, and carrying out thermal insulation for 1-2h; heating the furnace chamber of the heating furnace to 300-400 DEG C for 0.5-1 h, and carrying out thermal reaction for 3-6 h to obtain a reaction product; cooling the reaction product to room temperature, washing the reaction product with normal-temperature distilled water for several times to obtain a washed product; and drying the washed product at the temperature of 90-110 DEG C to obtain elemental silicon. The method is green and environmentally friendly, has advantages of low energy consumption, simple process, low cost and few and simple equipment, and is easy to use at large scale in the industry. In addition, purity of the prepared elemental silicon is high.

Description

technical field [0001] The invention relates to a method for preparing high-purity silicon by using energy-saving and environment-friendly technology. Background technique [0002] The existing method for producing high-purity silicon has the following deficiencies: 1. It pollutes the environment and produces pollutants such as carbon dioxide, trichlorosilane, and silicon tetrachloride during the production process; The reaction temperature is above 1000°C; 3. It is difficult to purify the obtained silicon (polysilicon, single crystal silicon); 4. The preparation process is complicated (more reaction steps), and the production cost is high (the price of raw materials is high), The equipment used must be resistant to high temperature and corrosion, and the structure is relatively complex. The above-mentioned lack of stuffing makes it difficult for the existing methods for preparing high-purity silicon to be used on a large scale in industry. Contents of the invention [0...

AI Technical Summary

Problems solved by technology

[0002] The existing method for producing high-purity silicon has the following deficiencies: 1. It pollutes the environment and produces pollutants such as carbon dioxide, trichlorosilane, and silicon tetrachloride during the production process; The reaction temperature is above 1000°C; 3. It is difficult to purify the obtained silicon (polysilicon, single crystal silicon); 4. The preparation process is complicated (more reaction steps), and the production cost is high (the price of raw materials is high), The equipment used must be resistant to high temperature and corrosion, and the structure is relatively complex

The above-mentioned lack of stuffing makes it difficult for the existing methods for preparing high-purity silicon to be used on a large scale in industry

Images