Novel Reaction Media of Na2CO3–CaO for Silicon Extraction and Aluminum Removal from Diamond Wire Saw Silicon Powder by Roasting–Smelting Process
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2020-03-06 |
| Journal | ACS Sustainable Chemistry & Engineering |
| Authors | Shicong Yang, Xiaohan Wan, Kuixian Wei, Wenhui Ma, Zhi Wang |
| Institutions | Yunnan Machinery Research and Design Institute, Kunming University of Science and Technology |
| Citations | 58 |
Abstract
Section titled “Abstract”Exploring a sustainable process to dispose diamond wire saw silicon powder (DWSSP) waste produced in the solar crystal silicon wafering process is a research field with significant theoretical research value and industrial engineering application. The current consensus on silicon extraction from DWSSP is that SiO2 oxide layer digestion and high-content Al removal are two main factors governing the yield and purity of silicon. To solve these problems, a novelty reaction media of Na2CO3-CaO in the induction furnace roasting-smelting process for silicon extraction and aluminum removal from DWSSP was proposed. The mechanisms of SiO2 digestion and Al removal during the roasting-smelting process were investigated by thermodynamic analysis, mineral transformation, and roasting-smelting experimental investigation. The obtained silicon with a Al removal efficiency of 48.44% and silicon yield of 55.5% was improved from 89.125% to 99.31% under the furnace feed mass composition of 38.4 g Na2CO3, 5.1 g CaO, and 300 g DWSSP, and holding time for 2 h in 1823 K. The novelty reaction media of Na2CO3-CaO is expected to achieve efficient silicon extraction and aluminum removal from DWSSP. This process provides an alternative choice for the commercial production of silicon alloy, silicone, and high purity silicon preparation with a process that is low in cost, is easy to operate, exhibits short flow, and can be sustainably manufactured.