ACARP ACARP ACARP ACARP
Coal Preparation

CPP Feed Washability Prediction from Small Top Size Samples

Coal Preparation » Gravity Separation

Published: July 16Project Number: C18041

Get ReportAuthor: Bruce Atkinson | QCC Resources

Coal Grain Analysis (CGA) characterisation by size and RD provides an amazing insight as to the nature of each particular coal type.

Maceral analysis quantifies a coal in terms of its coal matter components and mineral matter. From that point of view it provides an absolute theoretical delineation of 'marketable reserve' within a coal resource. However, in practice, the coal matter does not exist as discrete particles from the mineral matter. The 'ore' is composite in nature, with coal in the mineral matter, and vice versa.

Existing practice is that float and sink testing is used to estimate the yield of recoverable coal at some particular quality or separation criterion. Float and sink testing (F/S testing) is subject to poor reproducibility and its result is sensitive to the particle topsize and particle size distribution.

CGA assesses the maceral and mineral composition of individual grains (particles). Detailed information about each grain type is able to be deduced such as the relative density (RD) and analytical data such as proximate and ultimate.

Because CGA assesses individual particles, it addresses the short-coming of conventional maceral analysis and allows delineation of recoverable coal matter. Coal preparation requires separation of particles. The key strength of CGA technology is its ability to provide in-depth information on the individual particles (size and component makeup).

It is recommended that CGA should become an integral and fundamental tool for the purpose of definition of marketable reserves pursuant to the Coal Guidelines and The JORC Code as relevant to The VALMIN Code. This may require the CGA method to be formalised in some further manner.

Calculations in this report demonstrate that use of CGA should reduce the cost of resource assessment (drilling and analytical costs) by the order of 25% to 33%.

CGA is routinely undertaken on samples prepared to minus 1 mm. The key challenge for the project was to develop a way to interpret how to 'upscale' the information from -1 mm particles to 50 mm particles. That was achieved by using characterisation (CGA on every RD fraction of every size fraction from 63 mm down) to investigate how the coal grains distributed by size and RD for a given seam. Subsequently, that information was used in reverse as partition tables to provide prediction of both size and washability distribution using only a single raw coal CGA result.

Validation samples were based on the same seam but from totally different sample locations. The results from the validation samples were extremely encouraging.

The grain partition tables have been found to be seam-specific. It is not yet known whether the partition tables may be able to be correlated with rank (or some other parameter), so the technique relies on seam-specific characterisation in the first instance. It remains a potential area for further research to identify whether the CGA characterisation information for a particular seam in one locality may be extended to adjacent coal measures in the same locality.

 

This project has highlighted the difficulties that result due to the measurement uncertainty of F/S testing. That finding needs to be more widely understood, since coal industry personnel tend to think of float and sink testing as providing absolute data, which is not the case. Information included in an ASTM Standard provides an indication of the large magnitude of F/S testing measurement uncertainty, particularly at RDs of 1.40 and below where there is typically a large proportion of near-gravity material.

For the first time, the efficacy of F/S testing has been able to be directly assessed for the
-2+1 mm and -1+0.038 mm size fractions using CGA. The assessment has identified that fine float and sink testing exhibits severe misplacement errors.

The measurement uncertainty associated with F/S testing needs to be considered by Practitioners and Competent Persons who issue reports pursuant to The VALMIN and JORC Codes.

The recommendations arising from this report include:

· The 'power' of CGA needs to be imparted to the coal industry as a whole, preferably through a series of interactive workshops;

· A technology implementation Strategy and Task Plan need to be prepared so that industry users may adopt a structured and managed approach to implementation;

· Any specific requirements relating to use of CGA-generated data for the purposes of applying the Coal Guidelines to JORC and VALMIN reports needs to be coordinated with the relevant professional bodies and/or committees;

· The measurement uncertainty associated with float and sink testing for particles in the size range of 6.3 to 63 mm needs to be quantified;

· The CGA washability prediction methodology needs to be assessed for its potential to extend to adjacent coal measures within a locality (but that does not prevent its immediate implementation for seams that have been subject to CGA characterisation); and

· Model development, based on fundamental rather than numerical-data-fit methodology, is required in order to extend the prediction methodology beyond seams that have already been characterised.

 

Underground

Health and safety, productivity and environment initiatives.

Recently Completed Projects

C8005Impacts Of Mine Subsidence On The Strata & Hydrology Of River Valleys: Management Guidelines For Undermining Cliffs, Gorges & River Systems

THIS REPORT IS PROVIDED AS A SET, COMPRISING C8005, C9067 & C180...

C24024Drilling For Outburst Risk Determination

This project's purpose was to determine parameters that may be indic...

C24066Development Of An Alternative Electronic Spark Test Apparatus

Since a high profile incident in 1998, where two widely deployed IS cert...

Underground

Open Cut

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

Recently Completed Projects

C16007Development Of A Smart Condition Monitoring Sensor System For Variable Speed Machinery

The objective of this project was is to design and develop a wireles...

c21033Modelling The Water, Energy And Economic Nexus

The mining industry faces three long term strategic risks in relation to...

C18033Assessing The Ecotoxicology Of Salinity On Organisms In Seasonally Flowing Streams In The Fitzroy Catchment

Stage One Report: Development Of Ecosystem Protection Trigger Values ...

Open Cut

Coal Preparation

Maximising throughput and yield while minimising costs and emissions.

Recently Completed Projects

C21045Fine Coal Agglomeration Using A Novel Economic Binding Agent

In this project a novel economic binding agent was investigated for use ...

C24041Improving Coal Flotation With Oscillatory Air Supply

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

C22031Investigation Of The Graviton Separator At Pilot Scale

Vast quantities of fine coal, worth hundreds of millions of dollars, are...

Coal Preparation

Technical Market Support

Market acceptance and emphasising the advantages of Australian coals.

Recently Completed Projects

C12004Coke Reactivity Test: Critical Parameters

A Draft International Standard ISO/DIS 18894 has been prepared title...

C12073Accurate Instrumental Determination Of Carbon In Coal

Traditionally, thermal coal has been traded with its value being pri...

C13067Factors Affecting Coke Size And Fissuring During Cokemaking Part 2

This work addressed the mechanism of fissuring during metallurgical ...

Technical Market Support

Mine Site Greenhouse Mitigation

Mitigating greenhouse gas emissions from the production of coal.

Recently Completed Projects

C19054VAM Enrichment With A Two-Stage Adsorption Process

Treatment of ventilation air methane (VAM) with cost-effective technolog...

C24017Improving Methods For Quantifying Fugitive Emissions From Open Cut Coal Mining

Fugitive emissions from open cut coal mines are usually estimated fo...

C21065Flame Arresting Mechanisms And Flameproof Device For VAM Mitigation

The overall goal of this project was to study the gas flammability limit...

Mine Site Greenhouse 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

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 ...

C19025Governance Strategies To Manage And Monitor Cumulative Impacts At The Local And Regional Level

ACARP levy contributors should order this report in the normal manner – ...

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