成果報告書詳細
管理番号20110000000799
タイトル*平成22年度中間年報 太陽エネルギー技術研究開発 太陽光発電システム次世代高性能技術の開発 極限シリコン結晶太陽電池の研究開発(スライス時のカーフの回収・再利用)
公開日2011/7/28
報告書年度2010 - 2010
委託先名兵庫県立大学
プロジェクト番号P07015
部署名新エネルギー部
和文要約和文要約等以下本編抜粋:1. 研究開発の内容及び成果等
(1)カーフ/不純物の分離技術の開発
(1) スラリー特性の評価
スライス方式が遊離砥粒方式、固定砥粒方式どちらの場合も、分離をする上で最も重要な情報はどのような物質(Si 微粉末や砥粒)がどのような大きさで存在しているか、というスラリー特性を把握することである。そこで、クーラントとしてグリコールを用いている遊離砥粒方式および固定砥粒方式の廃棄スラリーを乾燥させ、残った固体のX 線回折(XRD)解析を行った。Fig.1 に両者のX 線回折パターンを示す。遊離砥粒方式の場合はSi 微粉末と砥粒であるSiC のピークが確認されたが、固定砥粒方式の場合はSi 微粉末のピークのみ現れており、遊離砥粒方式よりも分離が容易であることが示唆された。
英文要約Title : High Performance PV Generation System for the Future. R and D on Ultimate Wafer-based Si Solar Cells. / Recovery of silicon powder from multi-wire-saw sludge and reproduction to feedstock (FY2010-FY2012) FY2010 Annual report
(1) Development of separation process of silicon powder and impurities
(1-1) Characterization of waste slurry / sludge
In case of either loose abrasives and fixed abrasives slicing processes, characterization of waste slurry / sludge is important to develop a separation process. At first, in order to identify compounds in a solid phase, powder X-ray diffraction measurements were carried out. In the case of loose abrasives slicing, silicon and silicon carbide were confirmed in the solid. On the contrary, only silicon was confirmed in the case of fixed abrasive slicing. The result indicates that the fixed abrasive slicing is more suitable for waste recycling than the loose abrasive slicing.
Then, laser diffraction/scattering analysis was carried out to determine the size distribution of solid particles. In the case of loose abrasives slicing, the particle size was 0.1 to 6 [um]. On the other hand, the particle size was 0.6 to 3 [um].
(1-2) Preparation of calibration curve for Si-SiC mixtures
In order to evaluate silicon content in a solid phase, we examined the use of XRD patterns. We prepared standard samples with various silicon contents, and XRD patterns were obtained for each samples. As a result, we found that si content can be determined by using integrated intensities of Si(111) and SiC(111) diffractions.
(1-3) Search for high-density liquid for separation of Si and SiC
In order to control the density of liquid for separation, we prepared Sodium Polytungstate (SPT). We obtained heavy liquid with a density range of 1 to 3 [g/cm3] by dissolving the SPT into water. Since the densities of Si and SiC are 2.33 and 3.22 [g/cm3], respectively, the SPT solution with a density of 2.8[gcm3] can separate Si and SiC.
(1-4) Fundamental study of separation
In the case of loose abrasive slicing, it is necessary to separate Si and SiC. Therefore, we used the SPT solution and a centrifugal machine for separation. In the surface and bottom layers, Si contents are about 98 % and 10 %, respectively.
In the case of fixed abrasive slicing, we used a pressure filtration. The recovered silicon is over 90% in weight and the purity was almost 100%.
ダウンロード成果報告書データベース(ユーザ登録必須)から、ダウンロードしてください。

▲トップに戻る