Laser Plasma Control by Short/Long Pulse Coaxial Dropping for Metal Scrap Sorting

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K00620
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Environmental conscious materials and recycle
• Research Institution: Tohoku University
• Principal Investigator: Kashiwakura Shunsuke 東北大学, 金属材料研究所, 助教 (10589956)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: DP-LIBS / 高速分別 / 定量分析

Outline of Final Research Achievements

Laser-induced breakdown spectroscopy is a fast-response elemental analysis method that is expected to be applied to various industries, including the fast grouping of metal scrap. However, the low quantitativity of this method due to the instability of laser-induced plasma generation has been a problem. In the present study, we tried to improve the quantitative properties of the laser ablation by maintaining the electric field and temperature of the production field just before the laser-induced plasma production, and by preparing another laser to support the laser ablation. We also tried to apply the partial least-squares method, which is a method based on computational chemistry, and succeeded in improving the quantification accuracy compared with the calibration method, which is a common quantification method.

Free Research Field

資源循環・リサイクル

Academic Significance and Societal Importance of the Research Achievements

金属スクラップの最大の輸入国であった中国の第7類スクラップの輸入制限やバーゼル法の改正による小型家電などの不適正混入スクラップの輸出規制強化といったここ数年の影響を受け、金属スクラップの需給は今までにないほど逼迫している。これらの背景において金属スクラップの循環利用を更に推し進めるためにはこれまでの磁力選別に頼る分別では不十分であり、元素ベースの情報を用いて金属スクラップを分別し高付加価値化を推し進める必要があると考えられる。レーザー誘起ブレークダウン分光法の適用は上記目的と極めて相性のよい簡便な手法であり、今後とも研究の継続及び発展が必要であると考えらえる。