A method for electrochemical double refining and purification of high-purity silicon and high-purity aluminum

Abstract

The invention belongs to the technical field of purification of silicon and aluminum, particularly relates to an electrochemical double refining purification method for high purity silicon and high purity, which includes the following detailed steps: 1 refining and purifying alloy: mixing raw materials of metal aluminum and metallurgy silicon are smelted by adopting an alloy refining method, impurity boron in metallurgy silicon is removed, and aluminum-silicon alloy is obtained; 2 electrolytic separating: aluminum-silicon alloy serves as an anode, stainless steel serves as a cathode, low temperature fused salt serves as electrolyte, constant current electrolysis is conducted, anode mud gathered in the anode is polycrystalline silicon, and aluminum is gathered in the cathode; and 3 post-processing: the polycrystalline silicon gathered in the anode is smashed, acid pickled to remove impurities, washed by deionized water, filtered and dried to obtain low-boron polycrystalline silicon, the aluminum gathered in the cathode is washed and dried to obtain high purity aluminum. The electrochemical double refining purification method can effectively remove the impurity boron in the metallurgy silicon, is good in purification effect and high in environment-friendly benefit. Recycling rate of the aluminum is above 93%, and purity of the aluminum is above 99.999%.

Description

technical field [0001] The invention belongs to the technical field of silicon and aluminum purification, and in particular relates to a method for purifying silicon and aluminum by means of electrochemical double refining. Background technique [0002] As a highly environmentally friendly green renewable energy, the solar energy industry has been valued by the energy strategies of various countries, especially after the nuclear accident in Japan, the solar energy industry has heated up again. At the same time, the industry's requirements for solar cell materials are getting higher and higher. At present, the most widely used solar cells are silicon cells. In order to ensure its photoelectric conversion efficiency, the purity of its important component silicon material needs to reach more than 6N. The preparation of polysilicon for low-cost solar cells has become one of the bottlenecks in the widespread application of solar technology. [0003] The production method of so...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that the amount of alloy used is large, the consumption of reagents is large, and the problems of material circulation and energy consumption are prominent.

Especially aluminum, as an important light metal, its recycling price severely limits the purification cost of polysilicon

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