ACARP ACARP ACARP ACARP
Coal Preparation

Improved Dewatering in Fine Coal Centrifuges

Coal Preparation » Dewatering

Published: June 97Project Number: C4052

Get ReportAuthor: B Johnston, L Stapleton, C Veal, J Donnelly | CSIRO Energy Technology, James C Donnelly and Associates

This report summarises the results from a study aimed at improving the solids capture of scroll centrifuges. The main objective was to assess at pilot and commercial scales, the performance of a scroll centrifuge fitted with baskets of finer aperture (ie 250 or 125 ?m) compared with the conventionally fitted size of 375?m. Improved solids capture might allow the scroll centrifuge to be applied to finer feeds. It was intended to monitor the wear of the commercial scale basket which was to be hardened with a coating of tungsten carbide. In addition it was intended to gain a greater understanding of the main parameters which affect the performance of scroll centrifuges.

A literature review showed that there was virtually no prior published work on scroll centrifuges and that the proposed approach in this project had not been attempted before. After some preliminary bench scale tests and modelling, a series of trials were performed at a CMI pilot scale (ca 2 tph feed solids) scroll centrifuge at the Clarence CPP in NSW.

Unfortunately, no meaningful runs were possible with the 375?m basket due to rapid blinding with near size particles. In tests with the other baskets, the greatest influence on solids capture was not the basket aperture but the solids density of the feed, suggesting that the kinetics of bed formation is the controlling variable, and that the particle bed itself is the main medium for capturing particles and not the basket. Product moisture was determined primarily by feed size and centrifuge spin speed, which is not surprising but the extent of moisture reduction that could be achieved for relatively modest increases in spin speed was unexpected. Since there seemed little difference in the performance of the 250 and 125?m baskets, it was decided to opt for the coarser aperture for the commercial scale trial.

A 250?m tungsten carbide lined basket was trialed at Rix's Creek, CPP in the first half of 1998. Sampling runs were conducted in March and May.

The first objective, to improve fine coal dewatering, was not achieved. Moistures ranged from 20% to 43%. This may have been due in part to excessively fine feed, having 20-38% <100?m. The corresponding product contained 16% -30% <100?m.

The second objective, to improve solids capture, was achieved when the basket was in good condition. Sampling in March showed solids recovery 92% - 94%. However in May solids recovery had fallen to 75% - 79.8%. Over this period the mean aperture had worn from 287?m to 731?m.

The third objective, to extend basket life, was not achieved. On completion of the trial the basket had run for 611.5 hours, handling 16,896 tonnes of feed at an average rate of 27.6 tph. All the tungsten carbide coating had worn off, and the basket had failed in a number of places. Some anecdotal evidence is cited that much longer basket life has been achieved, but the plant in question could not locate operational records to confirm this belief.

The report recommends further, as the results of the pilot testing are quite encouraging. An alternative wedge wire profile is suggested.

Underground

Health and safety, productivity and environment initiatives.

Underground

Open Cut

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

Recently Completed Projects

C19024Establishing Ecologically Sustainable Mine Water Release Criteria In Seasonally Flowing Streams

Extreme rainfall conditions in the Fitzroy Catchment over an approxi...

C25030Coal Mine Open Pit Final Void Closure And Relinquishment - Addressing Uncertainty In Coal Mine Environmental Planning

This report addresses uncertainties faced by coal mine operators whe...

C27046Estimation Of True Deformation Vector From Slope Radar Monitoring

Slope deformation radar monitors are now widely used in open cut coa...

Open Cut

Coal Preparation

Maximising throughput and yield while minimising costs and emissions.

Recently Completed Projects

C27004Improving Coal Flotation With Oscillatory Air Supply

This report provides detailed information on coal flotation with os...

C25018Improving Solids Recovery And Moisture Reduction In Ultrafine Coal Dewatering

This report provides detailed information on fine coal dewatering in...

C27028Lab Froth Flotation Testing Guide With Coal Quality

Correct outcomes from laboratory froth flotation testing in coal bor...

Coal Preparation

Technical Market Support

Market acceptance and emphasising the advantages of Australian coals.

Recently Completed Projects

C26039Nanoporosity In Cokes: Their Origin, Control And Influence On CO2 Reactivity

This project using the outcomes of previous project C24060, examine...

C28063A Comprehensive Technical Review Of High-Efficiency Low-Emission (HELE) Pulverised Coal Combustion Technologies For Power Generation

Research and development has been undertaken worldwide to realise co...

C28064Carbon Structure Transformation During Coking Of Australian Coking Coals: Better Understanding The Coke Formation

Carbon structures of coke that are formed during the plastic layer a...

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) - Phase 2 Demonstration In A Packed Bed Reactor

An alternative approach to high temperature oxidation of ventilation...

C26004CFD Modelling Of Reverse Thermal Oxidisers For VAM Abatement - CFD Modelling Of Fixed-Bed RTO Devices

The project is part of a larger multi‐phase program of study a...

C27058Technological Assessment Of A Recycle Reactor For VAM Abatement

Underground coal mining emits high volumes of methane, diluted in ve...

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