Coal Preparation

Tailings to Topsoil

Coal Preparation » Environmental Improvement

Published: July 23Project Number: C29042

Get ReportAuthor: Kenneth Williams | The University of Newcastle

This project targets a co-utilisation and soil improvement program that addresses the environmental challenges associated with tailings management within mining operations. This transformational alternative for tailings management optimises existing technologies connected with dewatering, delivery, and soil remediation processes, and transforms it into an integrated pit-to-paddock mobile plant emplacement and cultivation system. It is a cost effective solution for tailings utilisation, with the target goal being the creation of a valuable topsoil supplement for restoration of native flora, or for the establishment of biomass crops for utilisation in next generation alternative energy technologies. Transforming coal tailings into a valuable resource will not only help reduce tailings dam requirements (and subsequent risks) but will also create re-vegetative land use opportunities.

The work within this project centres on four major processes relating to coal tailings; collection, characterisation, and pre-treatment; delivery to site; de-watering and emplacement; and assessment for mine site rehabilitation, focusing on improved soil health and plant productivity.

Forty-six coal tailings sampled from ten mines across New South Wales and Queensland were analysed for several chemical characteristics known to be important for soil health and plant productivity. Characterisation results were assessed for beneficial attributes and potential modification requirements. Findings showed the coal tailings to be alkaline, with a high total carbon content, and low levels of potentially toxic metals and metalloids. However, sulfur and sodium concentrations were elevated in some tailings, and thus, may require modification before use as a soil supplement.

Preliminary ex-situ (glasshouse) plant growth trials were conducted to help identify the types of coal tailings that could be used to supplement topsoil. Although the results from the trials were varied, there is potential that certain coal tailings could be used. The glasshouse trails were expanded upon through two in-situ field trials. These trials allowed for a more realistic assessment of coal tailings on plant growth, and also allowed for changes to the soil profile to be assessed. Plant growth results were varied, however, no obvious difference was observed between the plots with and without coal tailings. The soil profile assessment showed an increase in total organic carbon, which is a fundamental property for improved soil physical structure and the establishment of microorganisms.

An assessment of the emplacement rate of coal tailings was also conducted. It was calculated that for dry tailings production of 1.05 Mtpa with a tailings emplacement depth of 0.15m, that approximately 438 Ha of land could be covered. Subsequently, a mobile emplacement concept was developed based on a slurry feeding scenario. This included determining the design requirements associated with slurry flow and likely terrain scenarios. The final design incorporated a two-element machine system. Initially the slurry is fed into a drag wheel system, which allows slurry pipelines to be elongated and retracted as required. This system is attached to a to a mobile tracked “panther” prime mover, which houses a belt press filter to dewater and return the excess water to the drag wheel. The excess water is returned to the mine for use.

To identify the constituent coal tailings properties at real time, hyperspectroscopy (coupled with machine learning) offers a powerful toolset for tailings management and material property prediction. It has the potential to enhance the understanding of tailings characteristics and allows for a faster more streamline system by eliminating the need for traditional laboratory analysis. Furthermore, it facilitates responsible mining practices and enables sustainable resource management. Hyperspectral analysis was conducted on a selection of coal tailings samples and the predictive capability for several pre-determined characteristics was made.

The national benefits of this novel initiative are significant not only for its environmental solutions but also its commercial potential as a soil health enhancement product. The outcomes of the work could help reduce the need for tailings storage facilities, reduce costs and environmental risks of tailings management, generate productive and innovative uses of mined land, buffer zones, or land offsets, help convert mineral residue into a value-added soil improvement additive, and develop improved rehabilitated land or a new agribusiness.

The work presents a compelling opportunity to establish one form of large-scale tailings utilisation and has identified a solution to a major economic cost and environmental challenge related to tailings. A key feature of this work was the combination of research in several areas critical to achieving a successful cost-effective outcome in converting mine tailings into agricultural commodities for developing soil resources. The project provides a resourceful framework to transform tailings management into an effective usage for regional and national innovative advancements, and ultimately, allow for the utilisation of this product for energy crop production and revegetation of mine impacted sites.


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