Recycling and purification method of silicon cutting waste material

Abstract

The invention relates to a recycling and purification method of a silicon cutting waste material and belongs to the technical field of secondary resource circulation utilization of silicon materials.The recycling and purification method comprises the following steps: carrying out solid-liquid separation on silicon waste slurry in a silicon ingot cutting process, and drying to obtain a solid-statesilicon waste material; uniformly mixing CaO, SiO2 and a fluxing agent to obtain a slag-making agent; uniformly mixing the slag-making agent and the solid-state silicon waste material; putting a mixture into a medium frequency induction furnace; vacuumizing and then introducing argon gas; heating to 1450 to 1700 DEG C under an argon gas atmosphere condition and smelting at constant temperature for 0.5 to 4h; cooling along a furnace to obtain a fused block; separating silicon dreg of the fused block by adopting a diamond line cutting method to obtain high-purity silicon. According to the recycling and purification method, a silicon cutting waste material is subjected to slag-making and refining treatment of an induction furnace; separation and purification are carried out in the same operation step, and comprehensive recycling and purification treatment of a silicon-containing waste material in a silicon ingot cutting process is realized; the recycling and purification method has the characteristics of great production capability and high comprehensive recycling rate; wastes are changed into valuable things; the solar power generation cost can be reduced and a solar energy technology is easy to popularize.

Description

technical field [0001] The invention relates to a method for recycling and purifying silicon cutting waste, and belongs to the technical field of secondary resource recycling of silicon materials. Background technique [0002] Since the beginning of the 21st century, energy shortage and environmental degradation have increasingly become problems that countries need to face. As a kind of renewable energy, solar energy has been favored by people because of its cleanness, high efficiency and reliability, and has become a sharp tool to solve the above problems, and has a good development prospect. But at present, the cost of solar power generation in the photovoltaic industry is still very high. The reason is that polysilicon, as the basic raw material of the photovoltaic industry, is not only expensive but also irreplaceable in the short term. [0003] The most important step in the preparation of crystalline silicon solar cells is the preparation of silicon wafers. A very imp...

AI Technical Summary

Problems solved by technology

If the all-wet process is used, there are problems such as low production capacity, slow reaction speed, long process, and large corrosion of equipment in production practice. Some methods obtain silicon with low purity, so that the promotion is extremely slow.

However, if the semi-wet and semi-fire process is used, there will also be problems such as cumbersome process, which is contrary to people's urgent demand for effective recycling of silicon cutting waste.

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