ACARP ACARP ACARP ACARP
Coal Preparation

Stabilisation of Tailings and Water Recycling and Reuse

Coal Preparation » Environmental Improvement

Published: January 06Project Number: C15062

Get ReportAuthor: Philip Ofori, Bruce Firth | CSIRO Energy Technology

The coal industry recognises the significant challenges associated with the handling of fines rejects and with stabilising tailings dams with a high proportion of clay materials. Also the availability and cost of water is seen as an emerging problem. The industry wants to have better solutions than are currently available.

The main objective of this project was to examine the potential of paste technology as an effective and sustainable approach to tailings handling and water recovery. An approach that is increasingly being adopted in hard rock mineral processing plants for tailings treatment is paste technology. The Centre for Applied Energy Research, University of Kentucky (UKCAER) has been supported by the US Department of Energy (DoE) over the last few years to assess paste technology as an alternative approach to tailing enclosures in coal mining.

A partnership between CSIRO and UKCAER was established to evaluate paste thickening technology as applied to typical Australian tailings materials. In applying the technology to Australian tailings, the nature of the tailings was a major factor and required some changes to the reagent regime used to produce the best surface chemistry outcome. A comprehensive characterisation of the selected tailings materials was undertaken.

The investigation included laboratory and small pilot scale studies of the flocculated fine refuse solids for producing highly-thickened solids capable of disposal as a paste. The program included flocculant screening, batch settling tests for optimisation of flocculant dosage and feed solids concentration. This was followed by small scale, semi-batch and continuous paste thickening experiments and rheology tests to determine yield stress as a function of percent suspended solids of settled tailings. Two tailings samples were examined in this study, one sample from the Bowen Basin referred to in this discussion as Tailings Sample A, and another sample from the Hunter Valley referred to as Tailing Sample B.

The results of the study showed that for Tailings Sample A, Deep Cone thickening will be effective in producing a paste containing 50% solids from feed material of 15% solids.  The flocculant requirement would be 150 g/t of a high molecular weight anionic polymer.  The paste would have a yield stress of about 160 Pa, which is suitable in terms of pumpability and disposal as a paste.

The other tailings sample (Tailings Sample B) was found to be anomalous with respect to percent solids and ash. It contained a high percent solids and a high proportion of coal (55%) and was more difficult to flocculate even with both anionic and cationic flocculants as a majority of clays stayed in suspension. Thickening studies showed that about 42% solids could be achieved with this material. Vacuum filtration of the flocculated material produced only 51% solids, signifying some difficulty in dewatering this sample. More intensive pre-treatment may be required for this material. If a paste is required, then a processing step to recover some of the coal from the tailings may be required. Slurry containing high ash particles generally produces better thickened tailings.

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