Recovery of high purity Si from kerf-loss Si slurry waste by flotation method using PEA collector

Jingwei Li; Yinhe Lin; Jian Shi; Boyuan Ban; Jifei Sun; Yong Ma; Fanmao Wang; Wei Lv; Jian Chen

doi:10.1016/j.wasman.2020.07.023

Recovery of high purity Si from kerf-loss Si slurry waste by flotation method using PEA collector

Waste Manag. 2020 Sep:115:1-7. doi: 10.1016/j.wasman.2020.07.023. Epub 2020 Jul 21.

Authors

Jingwei Li¹, Yinhe Lin², Jian Shi³, Boyuan Ban³, Jifei Sun³, Yong Ma⁴, Fanmao Wang⁵, Wei Lv⁵, Jian Chen⁶

Affiliations

¹ Key Laboratory of Photovoltaic and Energy Conservation Materials, Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; Department of Materials Science and Engineering, University of Toronto, Toronto M5S 3E4, Canada. Electronic address: jwli@rntek.cas.cn.
² Energy and Environment Engineering Institute, Nanchang Institute of Technology, Nanchang 330000, China; School of Chemistry Engineering, Yangtze Normal University, Chongqing 408000, China. Electronic address: linyinhe2009@163.com.
³ Key Laboratory of Photovoltaic and Energy Conservation Materials, Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China.
⁴ School of Computer and Information Engineering, Jiangxi Normal University, Nanchang 330022, China.
⁵ Department of Materials Science and Engineering, University of Toronto, Toronto M5S 3E4, Canada.
⁶ Key Laboratory of Photovoltaic and Energy Conservation Materials, Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China. Electronic address: jchen@rntek.cas.cn.

PMID: 32707481
DOI: 10.1016/j.wasman.2020.07.023

Abstract

Separation and recovery of high-purity Si powder from kerf-loss Si slurry waste is a critical challenge for the photovoltaic industry. A green surfactant poly (propylene glycol) bis (2-aminopropyl ether) (PEA) was employed as a collector to facilitate the separation of Si and SiC from kerf-loss Si waste during flotation process. Single flotation tests of Si and SiC were conducted using 5 × 10^-6 mol/L PEA, respectively. The separation efficiencies of Si and SiC in conjunction with PEA adsorption mechanism were investigated. It was found that the maximum recoveries rate of SiC and Si were 90.59% (pH 9.00) and 80.93% (pH 1.96), respectively. Furthermore, the maximum Si grade was determined as 92.31% at pH 8.95 for the sinking part of the mixture generating excellent floatability and selectivity. Zeta potential measurements, FT-IR spectra, and XPS analyses demonstrated that PEA was present on the surface of Si and SiC through electrostatic and hydrogen-bond interactions. The adsorption mechanism was explained based on the results. This research provides an efficient and environmentally friendly route for the separation and recovery of high purity silicon from kerf-loss Si waste.

Keywords: Adsorption mechanism; Flotation separation; Kerf-loss silicon waste; Poly (propylene glycol) bis (2-aminopropyl ether); Si recovery.

MeSH terms

Adsorption
Pisum sativum*
Silicon*
Spectroscopy, Fourier Transform Infrared

Substances

Silicon