ACARP ACARP ACARP ACARP
Technical Market Support

Relevance of Maceral Concentrates to Whole Coal Coking Predictions

Technical Market Support » Metallurgical Coal

Published: December 19Project Number: C26046

Get ReportAuthor: Wei Xie, Rohan Stanger, Merrick Mahoney, Terry Wall, John Lucas, Karryn Warren, Graham O'Brien | University of Newcastle, CSIRO

Following on from earlier projects, C21059, C24055 and C25052, this project set out to use the reflux classifier to separate macerals and CGA to identify the structural components of the separated coal particles; and study the impact of these macerals concentrates and their blends on fluidity during coking.

The objectives of the project were to:

  • Clarify how to concentrate maceral components from coke oven feed particles combining the reflux classifier and Coal Grain Analysis;
  • Examine what maceral concentrates represent in whole coal and the extent of the concentrates and the blends modify industrial fluidity of whole coal; and
  • Establish the relevance of coal maceral concentrates on whole coal coking prediction.

Three coals with different ranks were selected for CGA prior to maceral separation. The results indicated that maceral compositions and populations (content as percentage) of these coals varied with coal particles, and the variation was different from coal to coal. Overall, for a single coal, the small particles had higher vitrinite contents than the large particles. Fine particles had a much higher proportion of grains containing highly concentrated-vitrinite (65-95%) than coarse particles, while coarse particles had a higher proportion of highly concentrated-inertinite (65-95%). Two size cuts of particles from each coal were selected for maceral separation. The reflux classifier produced products of lower density through to higher density, in effect concentrating macerals from high vitrinite to high inertinite. About 10% concentrates (by mass) were highly concentrated vitrinite and inertinite rich particles. Because coal maceral compositions are related to mineral content, particles that had similar ash contents with the raw coal were selected as heterogeneous particles along with the highly concentrated vitrinite and inertinite rich particles for CGA. The CGA results showed that the RC methodology could substantially shift the maceral distribution from an evenly mixed stream of high purity and dominant grain vitrinite (low flow rates) to streams containing an increasing amount of inertinite as dominant grain and composite grain (higher flow rates). Overall, the CGA results for the RC products indicated that the reflux classifier was able to separate the coal into a highly concentrated vitrinite product and inertinite rich stream regardless of feed vitrinite content. In practise, this mainly impacted the yield of products, rather than quality.

The Gieseler fluidity tests were undertaken to determine the coking impact of shifting the maceral distribution. Blends of “high purity” vitrinite and “concentrated inertinite” were produced to match the total maceral content in the heterogeneous product (from intermediate RC flow rate). The results suggested that the blends tend to decrease softening point and alter plastic range (2-7°C) and show higher fluidity than the heterogenous concentrates. However, the increase of fluidity for the blends seems not significant considering the accuracy of the fluidity test itself (repeatability = 0.1 log MF and Reproducibility = 0.3 log MF).

The fluidity of the maceral matched blends of the vitrinite and inertinite concentrates was also compared against the 2-component polymer blending prediction. The comparison indicated that this blending rule did not produce a predictive value of fluidity close to the measured value, nor provide an adequate trend in its differences. In past studies, this difference between predicted and measured values has been claimed to be a result of interaction. However, it is suggested in the outcomes of this project that an alternative reason may be that the polymer blending rule does not adequately account of solids such as inerts.

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