Review of Regenerative Technologies to Increase Longwall Advance Speeds

Underground » Mining Technology and Production

Published: March 15Project Number: C12022

Get ReportAuthor: Russell Smith | WBM

Longwall coal mining utilises hydraulically operated roof supports. The roof supports are often separated from the pumping hardware by more than 500m. It is perceived throughout the mining industry that the long hoses connecting the pumps and the roof supports introduce significant flow restrictions into the fluid path and compromise system performance.

The largest flow demands occur during "leg raise" of the roof supports. Due to the large area ratio of the leg cylinders (typically 10:1), only 1/10 of the leg raise fluid volume is required from the pumps during "leg lower", but a large fluid volume (the same as that required for leg raise) must be returned to tank over the long hose path.

"Regenerative" technologies aim to eliminate the transport of large fluid volumes fluid over long distances. Instead, the large fluid volume discharged during leg lower on one support is transferred locally (over a very short/low resistance fluid path) to a nearby roof support undergoing leg raise. As such, only the very small leg lower volume is supplied by the pumps.

This report presents performance predictions for a number of regenerative options and compares them with the predicted performance of a "generic" longwall. The generic longwall is modelled using component details typically found in Australian longwall installations.

The report includes descriptions and details of the hydraulic circuit components and how they affect system performance. Simple static analyses of the main roof support functions are included to help develop an appreciation of the critical hydraulic circuit variables. Dynamic analyses are used for more comprehensive consideration of the real longwall conditions. The dynamic analysis results are used for the final comparisons of the alternatives.

Based on the results of the dynamic modelling WBM concludes regenerative technologies are unlikely to offer a viable benefit to longwall performance. This outcome is driven primarily by the realisation that the long hose runs in modern longwalls are not the critical influence they are commonly perceived to be. Additionally, extra valves are required to implement regenerative technologies, and these further degrade the system performance. Additional valving implementation and maintenance costs could be more effectively invested by purchasing improved conventional hydraulic systems (better valves and control strategies etc.)

The dynamic modelling tools used for assessment purposes during this project were not available at the time the project commenced. Development of the dynamic models forms part of the in kind contribution to the project made by WBM. Having established that regenerative concepts would be less beneficial than had been hoped, rather than expending resources on detailed investigation of these concepts, the time was spent identifying and documenting the principles that will provide the basis of real performance gains in longwall hydraulic systems.

The report concludes with an expected cost-benefit ranking of a number of new options aiming to improve system performance. This ranking should help prioritise further analysis required to validate the options prior to implementation.


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...


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.

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