Laser-induced breakdown spectroscpopy (LIBS)
Swerim has internationally recognized research in LIBS (laser-induced breakdown spectroscopy) and works with development to improve and implement LIBS on-line in industrial applications. LIBS is an optical measurement method with unique properties to enable process control based on chemical analysis. The analysis is fast, contact-free and can simultaneously analyze all elements in the periodic table ‒ on all shapes and types of materials ‒ in all aggregation states!
From the left: 1. Identification in scrap sorting. 2. Different type of materials. 3. Slag for chemical analysis which enables process control.
What is LIBS?
Laser-induced breakdown spectroscopy (LIBS) is a laser-based measurement method for rapid chemical analysis of materials. The measurement mainly provides information about the elemental composition, but some molecular information can also be obtained. It is e.g. possible to translate the signal to the content of oxides and make both quantitative and qualitative analysis. LIBS is a method for surface analysis, but by analyzing each laser pulse (shot-to-shot), depth information can also be obtained, and surfaces can be mapped systematically.
Movie on field trials.
LIBS in detail
A laser with high energy and short pulses heats up and evaporates –ablates, a small amount of the material (a few ng) and induces an energy-rich plasma. That plasma emits light with wavelengths specific to each element where each element in the periodic table has a characteristic spectrum. The light is collected in a spectrometer, where the wavelengths are divided and converted into an electrical signal that can be read by a computer.
Schematic figure of LIBS.
Possibilities with LIBS
Through funding from Vinnova, EU (RFCS, Horizon, EIT Rawmaterials), Energimyndigheten, Formas, Strategic competence funds, etc., we carry out collaborative projects together with industry and other research institutes. The possibilities are several.
There are several advantages of LIBS: an equipment can be flexibly adapted based on the needs, can be used on-line, the measurement is contactless, the material can be in all aggregation states and does not need sample preparation or smooth surface, the analysis can be done quickly and as quantification of content or classification and it is possible to follow the process remotely.
The challenge with LIBS is to design the optics so that there are stable signals. The resulting spectra are a combination of many complex processes in the plasma and each new application requires a carefully designed method for data evaluation.
With the help of expert competence and experience of LIBS, we can both gain and provide completely new insights about the studied process!
Developed LIBS equipment with on-line measurement on mesa in the industry.
One of the benefits of LIBS is that it can be used remote.
Examples of projects
Further is some examples of projects and solutions we have conducted together with companies and stakeholders:
- AUSOM Project – Automatic Sorting of Mixed Scrap Metals
- SenSoRe – Sensors and sorting for innovative recycling| Swerim
- CONSENO – Continuous sensing for the on‐line monitoring of metallurgical processes
- Sorting of production waste (Outukumpu)
- Monitoring of metallic scrap flows (Stena, Sweden)
- Sorting of metal scrap (China)
- Monitoring of metallic scrap flows (Brazil)
- Process control of hot slag and metal with continuous detection on-line (e.g. Paroc, Sandvik)
- Identification of steel scrap, aluminium, black plastic
- Analysis of mesa and pulp (pappersmassa) (Project OnlineLIBS)
- Analysis of gas in vacuum degassing (Project AVGAS)
- Monitoring of continuous casting (Project LACOMORE)
- Analysis of ore (Project OM-LIBS)
- Quality controls (scrap, cast material, slag)
Publications
- A. Bengtson, Laser induced Breakdown Spectroscopy compared with conventional plasma optical emission techniques for the analysis of metals - A review of applications and analytical performance (2017)
- J. Pettersson, M. Gilbert-Gatty and A. Bengtson, Rapid chemical analysis of steel slag by laser-induced breakdown spectroscopy for near-the-line applications (2020)
- J. Gurell, A. Bengtson, M. Falkenström, B.A.M. Hansson, Laser induced breakdown spectroscopy for fast elemental analysis and sorting of metallic scrap pieces using certified reference materials (2012)
- B. Noharet, C. Sterner, T. Irebo, J. Gurell, A. Bengtson, R. Vanik, H. Karlsson, E. Illy, A compact LIBS system for industrial applications (2015)
- B. Noharet, T. Irebo, C. Sterner, M. Ek, H. Karlsson, Improved Metal Recycling - Industrial processes based on laser induced breakdown spectroscopy (LIBS) can benifit from the use of compact high-repetition-rate solid-state lasers (2016)
- The Steel Eco-Cycle Report 2004-2012
- LIBS outside Swerim: ChemCam for Scientists | ChemCam – NASA’s Mars Exploration Program
Contact
