The dissolution behavior of boron in a molten slag was evaluated at 1773K to establish the boron removal mechanism from silicon refining for preparing higher purity solar-grade silicon. From the experimental results, a mechanism of boron removal from silicon into the CaO-SiO2-Al2O3 slag system was confirmed to proceed via BO33- and B62- following a linear relationship with oxygen partial pressure in the slag system. In addition, the distribution ratio of boron was seen to increase with increasing slag basicity.6B+1/3O2-=B62-+1/6O2(g)The boride capacity of the CaO-SiO2-Al2O3 slag can be expressed as a linear function of the activity of CaO and the optical basicity. It is suggested that the proposed dissolution mechanism of boron could be appropriate to slag systems, depending on oxygen partial pressure and basicity.
Bibliographical noteFunding Information:
This work was supported by the Research Institute of Industrial Science & Technology (RIST) and the New and Renewable Energy of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korean Government Ministry of Knowledge Economy .
All Science Journal Classification (ASJC) codes
- Civil and Structural Engineering
- Building and Construction
- Mechanical Engineering
- Industrial and Manufacturing Engineering
- Electrical and Electronic Engineering