Method for preparing solar-grade silicon by refining industrial silicon

一种精炼工业硅制备太阳能级硅的方法

Abstract

本发明公开的是一种精炼工业硅制备太阳能级硅的方法,主要解决了现有冶金法制备太阳能级多晶硅工艺路线都比较长、设备较复杂、成本较高以及工艺的可控性较差等问题。本发明包括以下步骤:(1)冶金级硅在炉内熔化后获得硅熔体,向炉内通入保护气体和精炼气体,进行造渣精炼;所述造渣精炼包括低温造渣阶段、中温造渣阶段和高温造渣阶段;(2)造渣精炼后再进行真空精炼;(3)真空精炼完成后将熔体硅进行分凝精炼,分凝精炼后通过定向凝固获得成品。本发明具有投资少、操作方便、节能、可适用于大规模生产等优点。
The invention discloses a method for preparing solar-grade silicon by refining industrial silicon. The problems of longer routes, more complicated equipment, higher cost, poorer process controllability and the like of existing processes for preparing solar-grade polycrystalline silicon by adopting a metallurgic method are mainly solved. The method includes the following steps that (1) metallurgical-grade silicon are molten in a furnace to obtain a silicon melt, protective gas and refinery gas are led to the furnace to perform slagging and refining, the slagging and refining operation includes a low-temperature slagging stage, a middle-temperature slagging stage and a high-temperature slagging stage; (2) vacuum refining is performed after slagging and refining; (3) the silicon melt is segregated and refined after vacuum refining is completed, and a finished product is obtained through directional solidification after segregation and refining. The method has the advantages of being low in investment, convenient to operate, capable of saving energy, suitable for large-scale production and the like.

Claims

Description

Topics

Download Full PDF Version (Non-Commercial Use)

Patent Citations (0)

    Publication numberPublication dateAssigneeTitle

NO-Patent Citations (0)

    Title

Cited By (0)

    Publication numberPublication dateAssigneeTitle