ACARP ACARP ACARP ACARP
Underground

Active Explosion Barriers and Stone Dusting Options

Underground » Detection and Prevention of Fires and Explosions

Published: May 98Project Number: C6018

Get ReportAuthor: Berger Jensen, Terry O'Beirne | ACIRL

Current Australian stone dusting regulations have their research origins as far back as the 1920s. However, changing mining practices have progressively increased the generation of coal dust and reduced its particle size. As particle size affects the explosibility of coal dusts, current inerting levels have therefore been rendered obsolete and an increase to levels discussed in this report is recommended.

Testing a range of Australian coals and dust particle sizes shows the minimum incombustibles requirement is between 65% and 90% depending mainly on the initiation energy and stone dust particle size. Assuming current stone dust sizes, and without mine specific testing, the incombustible content of settled dust should be increased to a minimum of 90% to markedly change the effectiveness of this risk management strategy. Even at 90% there is little or no margin of safety to cover all credible circumstances, including the presence of flammable gas. This inerting level represents the total inerts concentration; that is, it includes the ash and moisture contents of the cost dust. This value could be difficult to consistently achieve in some high production mines.

The effectiveness of stone dust used in Australian mines can be improved by reducing its particle size and/or adding chemical suppressants. Further research is required to determine if these strategies could offset the need for increased dusting, and even reduce the level of inertisation, as suggested by this report.

The results from the limited local testing of the effect of stone dust particle size on inerting levels shows a broad improvement with decreasing particle size. This is probably related to the finding that of the order of only 2% of dust dispersed by the pressure front has particle sizes >250?m, irrespective of the particle size distribution of the settled dust from which it was raised. More extensive research undertaken in Canada and the United States confirms that the use of finer stone dust particle sizes increases effectiveness and is therefore recommended. This overseas research suggests the use of stone dust with an optimal particle size distribution, as detailed in the report, could reduce the total inerts requirement.

This study has been unable to generate a strong relationship between dust explosibility and volatile content as found in the UK and USA. The report discusses the likely conclusion that Australian coal dusts should be considered to behave differently in a flame zone compared to Northern Hemisphere dusts. This is because there is considerable variability in the macerals analysis and the grain size of vitrinite in Australian coals. The same conclusion has been drawn in relation to South African coals. Accordingly, in the absence of additional testing, the current regulatory based linkage should be abandoned in favour of a single value, or a value linked to the presence of flammable gas.

The concept of mine-wide explosion protection solely by general dusting appears to be seriously flawed. This study has shown explosion with Australian coal dusts can be propagated at 90% inerts, a level that will be difficult to consistently achieve. These results suggest a secondary explosion protection strategy is required to reduce the irks to as low as reasonably achievable. This could be in the form of more effective passive barriers, triggered barriers at the face or outbye, or more likely, some combination of all of these.

Underground

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...

C27049Mine Machine Radar Sensor Integration

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

C29007Innovative Coal Burst System To Investigate The Influence Of Confinement Loss And Pre-Conditioning On Coal Burst Mechanism

The challenges associated with designing and operating a safe and pr...

Underground

Open Cut

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

Recently Completed Projects

C33035High Water Recovery, Low Cost Desalination Using PV-Powered Membrane Capacitive Deionisation (Mcdi)

Capacitive deionization is a robust, energy efficient and cost effec...

C28035Topsoil Deficits In Site Rehabilitation Accelerated Transformation Of Spoils To Functional Soils

The incorporation of commercial biological amendments (compost, worm...

C34036Tyre Handler Testing Rig Stage 2: Lifting Trials

Tyre handling is a major source of risk in surface mining operations...

Open Cut

Coal Preparation

Maximising throughput and yield while minimising costs and emissions.

Coal Preparation

Technical Market Support

Market acceptance and emphasising the advantages of Australian coals.

Recently Completed Projects

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...

C29071Source Of Variability Of Reactivity Of Coke In The CSR Test

The Coke Strength after Reaction (CSR) test is used worldwide to det...

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

NERDDC

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

NERDDC