Open Cut

Validation of Laser Induced Breakdown Spectroscopy (LIBS) as a Rapidly Deployable Field Technology to Estimate Coal Quality

Open Cut » Geology

Published: June 24Project Number: C34029

Get ReportAuthor: Joe Perkins & Chad Hargrave | CSIRO

Rapid evaluation of a coal resource by in-situ characterisation downhole can dramatically enhance understanding of the resource, providing new knowledge regarding coal quality - particularly grade - to inform the mining process and improve yield.

LIBS is swiftly becoming an established technology and it shows promise as a rapid analytical method for coal characterisation. LIBS hardware modified to fit smaller diameter exploration holes (<100 mm) and deliver one or several coal quality measures with an accuracy akin to laboratory testing would therefore be immensely valuable and enable coal producers to make more informed decisions in the field.

However, it has yet to be successfully adapted for use downhole due to the cost and specificity of development LIBS hardware and the unique challenges of remote tool operation in a downhole environment. A successful technology demonstration on unprepared coal core would identify the further research and engineering developments required to adapt the LIBS hardware as a downhole tool.

This proof-of-concept project was comprised of three sections:

  • Task 1: Determine a device calibration protocol
  • Task 2: Core specific calibration   
  • Task 3: Field test simulations on coal core  

A sample set of 12 test coals were used to derive and optimise calibration protocols for major coal quality metrics using a handheld LIBS device.  

Despite varying matrix effects between coal samples the likely major contributor to model error, viable relationships (<10% relative error) between LIBS spectra and rank, ash, fixed carbon, calorific value and ultimate analysis values could be derived. More indicative relationships (>10% relative error) for moisture, volatile matter and density were also obtained. Sulphur could not be detected during these investigations, a common finding in LIBS analysis of coal.  Future work utilising spectrometers with enhanced resolution (particularly in the UV and NIR ranges) may be able to overcome sensitivity issues as demonstrated by a small number of literature publications.  

The device was successfully calibrated for a 2-meter section of PQ coal core, resulting in significant enhancements in curve fitting and relative error (<2%) compared to the test coal sample set. This suggests that calibration on target coal seam and associated mineral matter, a strategy known as 'matrix-matching,' would likely be necessary to ensure accuracy for a potential future field or downhole deployable LIBS device.

LIBS coal quality results obtained from an unprepared coal core were generally encouraging, with relative errors ranging from 4-10% compared to lab testing. However, these results were inferior to the pelletised calibration results, which showed a relative error of only 1-2%. This suggests that whilst meaningful information was still obtained, the volume of spectra collected during this work and/or the laser spot size were likely insufficient to compensate for the increased roughness, heterogeneity, and larger mean grain size present in the coal core.

Testing LIBS on coal cores in a lab setting provided a controlled and reproducible experimental environment for this proof-of-concept project. The primary aim was to showcase the feasibility of obtaining meaningful results without the need for extensive sample preparation, thus evaluating LIBS as a viable technique for analysing exploration holes and warranting further investigation.

This study has demonstrated that, although not yet on par with lab analysis, viable coal quality results can be obtained directly from unprepared coal cores using a low-cost, off-the-shelf LIBS device and relatively simple chemometric calibration methods.


Health and safety, productivity and environment initiatives.

Recently Completed Projects

C34019Longwall Bretby Cable Handling Monitoring With Fibre Optics

This project examined the potential of using fibre optic sensing tec...

C28028The Inclusion Of High Interest Native Plants In Mine Site Restoration Programs: Propagation, Translocation And Field Re-Introduction

This report synthesises over 10 years of ex situ and in si...

C27049Mine Machine Radar Sensor Integration

The aim of this project was to develop an integrated radar sensor an...


Open Cut

Safety, productivity and the right to operate are priorities for open cut mine research.

Recently Completed Projects

C34029Validation Of Laser Induced Breakdown Spectroscopy (LIBS) As A Rapidly Deployable Field Technology To Estimate Coal Quality

Rapid evaluation of a coal resource by in-situ characterisation dow...

C34028Guidelines For Assessment Of Geotechnically Safe And Stable Post-Mining Landforms

The purpose of this project was to develop a guidelines document as ...

C34016Elements In Coal – A Start-To-End Analysis

This project explores the fate and concentration potential of critical e...

Open Cut

Coal Preparation

Maximising throughput and yield while minimising costs and emissions.

Recently Completed Projects

C26016Determining The Benefits Of Online Thickener Underflow Rheology Measurements

The aim of this project is to determine how useful the rheology meas...

C33056Modelling And Control Of Classifying Cyclones

Hydrocyclones are one of the key technologies for the classification...

C28056Surface Alloying Of Centrifuge Baskets And Sieve Bends Screen Surfaces To Increase The Service Lifetime

The main objective of this project was to improve the wear resistanc...

Coal Preparation

Technical Market Support

Market acceptance and emphasising the advantages of Australian coals.

Recently Completed Projects

C33066Washability And Distribution Of Sulfur And Trace Elements For Different Size And Density Fractions Of Raw Coals

Based on the hypothesis that the levels of sulfur and other toxic tr...

C34060In-Situ Investigation Of Coke Structure Formation Under Stamp Charged Coking Conditions

Stamp charged cokemaking has emerged as an effective technique to im...

C34062Improving The Classification Of Microstructure Distribution In Coke CT Images Using Deep Learning And Lineal Path Calculations

This project builds on a number of earlier projects that have helped...

Technical Market Support

Mine Site Greenhouse Gas Mitigation

Mitigating greenhouse gas emissions from the production of coal.

Recently Completed Projects

C28076Selective Absorption Of Methane By Ionic Liquids (SAMIL)

This third and final stage of this project was the culmination of a ...

C29069Low-Cost Catalyst Materials For Effective VAM Catalytic Oxidation

Application of ventilation air methane (VAM) thermal oxidiser requir...

C23052Novel Stone Dust Looping Process For Ventilation Air Methane Abatement

This multi‐phase project is concerned with the mitigation of m...

Mine Site Greenhouse Gas Mitigation

Low Emission Coal Use

Step-change technologies aimed at reducing greenhouse gas emissions.

Recently Completed Projects

C17060BGasification Of Australian Coals

Four Australian coals were trialled in the Siemens 5 MWth pilot scale ga...

C17060AOxyfuel Technology For Carbon Capture And Storage Critical Clean Coal Technology - Interim Support

The status of oxy-fuel technology for first-generation plant is indicate...

C18007Review Of Underground Coal Gasification

This report consists of a broad review of underground coal gasification,...

Low Emission Coal Use

Mining And The Community

The relationship between mines and the local community.

Recently Completed Projects

C16027Assessing Housing And Labour Market Impacts Of Mining Developments In Bowen Basin Communities

The focus of this ACARP-funded project has been to identify a number...

C22029Understanding And Managing Cumulative Impacts Of Coal Mining And Other Land Uses In Regions With Diversified Economies

The coal industry operates in the context of competing land-uses that sh...

C23016Approval And Planning Assessment Of Black Coal Mines In NSW And Qld: A Review Of Economic Assessment Techniques

This reports on issues surrounding economic assessment and analysis ...

Mining And The Community


National Energy Research,Development & Demonstration Council (NERDDC) reports - pre 1992.

Recently Completed Projects

1609-C1609Self Heating of Spoil Piles from Open Cut Coal Mines

Self Heating of Spoil Piles from Open Cut Coal Mines

1301-C1301Stress Control Methods for Optimised Development...

Stress Control Methods for Optimised Development and Extraction Operations

0033-C1356Commissioned Report: Australian Thermal Coals...

Commissioned Report: Australian Thermal Coals - An Industry Handbook