ACARP ACARP ACARP ACARP
Coal Preparation

Enhanced Coal Flotation using Picobubbles

Coal Preparation » Fine Coal

Published: September 02Project Number: C9048

Get ReportAuthor: Glenn Hart, S Morgan, N Bramall, Stuart Nicol | CSIRO Energy Technology, Novatech Consulting

The objective of this project was to provide a simple retrofittable device to enhance the flotation behaviour of poorly floating coals. A device capable of inducing cavitation in flotation feed generates very small "picobubbles" on the surface of coal particles, which have a greater affinity for attaching to larger bubbles than the coal surface itself, ie they act as a collector.

Various designs of cavitation device were assessed to determine which was the most applicable for our operation. A venturi design was identified as the best option, with its critical features being:

  • the ability to set the throat length, and
  • the ability to control the pressure recovery after cavitation.

A unit was designed and fabricated that matched the process capacity of the pilot scale mechanical flotation unit located at CSIRO's Catherine Hill Bay facility. A comprehensive test program using Catherine Hill Bay flotation feed with and without cavitation was undertaken. Variables were monitored, and a statistically based test program was undertaken to define critical variables and their possible interaction.

The cavitation device was also operated with a pilot scale Jameson cell and a Column flotation cell.

The results with mechanical cells showed that the use of a cavitation unit increased the yield of flotation product, while reducing the diesel collector dose by up to 50%. The statistical analysis of test runs showed that the collector dosing and use of cavitation unit were significant factors with respect to combustible recovery, while collector dose and feed rate were significant factors with respect to product ash. This analysis also showed that there was no interaction between factors, such as collector dose and cavitation.

The results for column flotation showed that increased combustible recovery can be achieved with use of cavitation when operated at low chemical dosing of collector compared to conventional high dose operations. However, our results also showed an increase in product ash for cavitated runs. The reason for this is unclear at this present time.

The results for tests with the Jameson cell were not encouraging. Cavitation actually decreased combustible recovery compared to conventional operation. It is thought that the use of a cavitation plate at the top of the downcomer may diminish the effectiveness of picobubbles formed in the cavitation device placed prior to the cavitation plate.

The effective use of a cavitation device at pilot scale has been demonstrated, and the results suggest that it would work at a larger scale. The issues facing installation of a cavitation unit into a flotation feed stream are mainly engineering concerns, such as where to place the device, is an extra sump and pump needed to ensure correct flow condition for the device, and can they be housed close to the flotation cells.

The results show that cavitation would have its most significant effect in reducing the use of collector. With a cost of collector such as diesel at 70 cents/litre, a 50% reduction in diesel use could save approximately $350,000 per annum for a plant processing 5 million tonnes per annum with 20% reporting to flotation.

Testing of candidate coals can now be done routinely with CSIRO's test facility at QCAT Brisbane, so selection of coals responsive to the technology would be a relatively simple process.

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