Technical Market Support

The Behaviour of Export Thermal Coals

The combustion behaviour of inertinite and vitrinite macerals in coal were studied by two methods: Drop Tube Furnace (ACIRL) and Laser Nanoreactor (CSIRO).

New Approach to Determining Trace Elements in Coal

Increasing concern on the environmental impact of electricity generation from coal-fired power plants has focussed greater attention on the levels of trace elements in thermal coals. This has been mainly due to current and proposed legislation in may countries which places limits on the ....  read more

Coal Combustion Testing: New Laboratory Procedure

The major objective of the work is the establishment of an effective testing facility to measure the combustion reactivity of pulverised coals.  The facility would use pyrometry techniques with measurements on individual particles being obtained relating to the following coal reactivity ....  read more

Australian Coal Quality Impact Model

This project examines the ability of CQIM (version 1.2) to predict the performance of Australian coals in some of the many processes that occur in a modern coal-fired power station.  The continued growth in the world thermal coal market is resulting in greater diversity in thermal coal ....  read more

Improved Ash Fusion Test

A new method of the measurement of Ash Fusion Temperatures has been developed using essentially the same equipment as is used for the measurement of ash fusibility under Standards such as AS1038, 15-87 and ASTM D1857-87. However,  ....  read more

Demonstration of the True Ash Fusibility Characteristics of Australian Thermal Coals

The objective of this report is to integrate the work undertaken in ACARP projects on ash fusibility conducted by ACIRL and the ICR. The objectives of the projects are to provide alternative procedures for the measurement of ash fusibility (ash fusion temperature - AFT) together with an ....  read more

Trace Elements in Internationally Traded Thermal Coals

Trace elements in coal are receiving greater attention in the assessment of the environmental impact of electricity generation from coal-fired power stations. The levels of many trace elements of environmental concern are now assuming greater importance in terms of emission of air toxics, ....  read more

Evaluate Combustion Behaviour of Australian Export and Overseas Low Rank Coal Blends

The increasing growth of the world thermal coal market is seeing more producers from Australia, Indonesia, South Africa, Colombia, USA and Canada entering the market. The coals from these exporting countries differ ....  read more

Optimisation of the Improved Ash Fusion Test

A new method of the measurement of Ash Fusion Temperatures has been developed using essentially the same equipment as is used for the measurement of ash fusibility under Standards such as AS1038.15-87 and ASTM D1857-87. However, unlike the standard method the new method produces quantitative ....  read more

Elucidation of the Improved Ash Fusion Test

The aim of the project was to understand the processes that produced the response observed in the Improved Ash Fusion test (IAFT).  The initial objective of the project was to determine that the changes observed in the improved Ash Fusion test were relatable to known mineralogical changes ....  read more

Developing and Understanding the Ash Fusion Test - Joint Report on C3092, C3093, C4060 and C4061

The objective of this report is to integrate the work undertaken in ACARP projects on ash fusibility conducted by ACIRL and the ICR. The objectives of the projects are to provide alternative procedures for the measurement of ash fusibility (ash fusion temperature - AFT) together with an ....  read more

Application of Coal Textural Analysis to Predict Grinding Behaviour and Product Composition in Austr

The project set out to develop a technique for the prediction of grindability parameters such as optimum liberation energy, particle size distribution and size fraction composition for pulverised fuel in advance of coal processing.   To achieve this ....  read more

Ash Formation Involving Siderite Performance of PF Fired Plants

The mineral form of the iron in coal has a fundamental influence on the observed extent and severity of the ash deposition problems encountered during combustion. There has been ....  read more

Improved Techniques for the Prediction of NOx Formation from Char Nitrogen

This study has shown that under staged-air conditions (such as those in low-nox burners) commonly now used to reduce emissions, the ultimate NOx emissions will be, to a large extent, determined by the char-n.  The results show that around half of the char nitrogen will be converted to ....  read more

Practical Application of the Improved Ash Fusion Test

The main objective of the present report is to investigate the practical applicability of the Improved Ash Fusion Test for a suite of selected coals that were previously investigated in ACARP Project C3097 Evaluate Combustion Behaviour of Australian Export and Overseas Low Rank Coal ....  read more

The Application of Differential Thermal Analysis (DTA) to Coal Ash Characterisation and Ash Fusion T

This report presents the results of a scoping study which details the potential for application of Differential Thermal Analysis (DTA) combined with thermogravimetric analysis (TGA), for investigation of the ash fusion characteristics of thermal coals. DTA/TGA results have been recorded on ....  read more

New Analytical Approach to Determining Minerals in Coal and Ash Products Using X-Ray Diffraction

Background Coal mineral matter, particularly its composition, plays an important role in all phases of coal science from mine geology, resource development, preparation and utilisation. In the past, techniques available for determining individual mineral phases lacked the necessary ....  read more

Demonstration of the True Ash Fusibility Characteristics of Australian Thermal Coals. Stage 2: Prov

The current ash fusibility temperature (AFT) test can give differences in estimates of up to 300°C for some coal ashes. This irreproducibility led to the testing of a range of methods for determining the fusibility temperatures of coal ashes.  The use of shrinkage levels for an ash sample ....  read more

Standard Analytical Methods for Trace Elements in Coal

The levels of trace elements in thermal coals are coming under increased scrutiny by power generating companies because of the potential environmental impact from atmospheric emissions of trace elements and their leaching from ash disposal systems. In some countries there are legislated ....  read more

New Method for Determining Chlorine in Coal

A new reference method based on x-ray fluorescence spectrometry has been developed to more accurately measure chlorine in coal.  Accurate chlorine measurement is critical for some coal producers. Elevated levels of chlorine in coal can cause corrosion problems as well as having the ....  read more

Prediction of NOx Emissions

This report is a compilation of three separate but related studies, conducted as part of a major NOx emissions project by the Black Coal CRC.

The first study, conducted by CRE Group Ltd in the UK and managed by Ken Sullivan and Associates, tested eight Australian coals using laboratory ....  read more

Making the Ash Fusion Temperature Test Useful

This project addressed uncertainties related to ash fusion temperature (AFT) measurements for the prediction of ash deposition in utility boilers. The approach to elucidate areas of concern included:

• correlation of the melting characteristics of a range of coal ashes with

Trace Element Leaching From Fly Ash from Australian Power Stations

Coal-fired power stations produce large quantities of waste ash and fly ash represents around 80-90% of the total produced. Fly ash contains many trace elements of environmental concern that may become mobile in the ash dam water resulting in the potential to impact on the surrounding ....  read more

Use of a Laboratory Scale Method for Assessing Ash Deposition Characteristics of Australian Coals in Utility Boilers

The deposition of ash in power station boilers can lead to a loss in efficiency and availability. Also, slag deposited around low NOX burners and on furnace walls can lead to poor boiler performance, high furnace temperatures and increases in NOX emissions. Reliable means of minimising the ....  read more

Development of an International Standard for Determining Trace Elements in Coal

There are no international standard methods for the determination of trace elements in coal. One of the coauthors (K.W. Riley) as an Australian representative on the Subcommittee for the analysis of solid mineral fuels, TC 27 SC 5 of the International Organisation for Standardisation (ISO) has ....  read more

Automatic Ash Fusion Test

This project has developed a prototype automatic ash fusion temperature measuring system (AAFT) that demonstrates that digital imaging techniques can automate and overcome the problems of the Standard system of measurement. Furthermore, the developed system is closely based on the current AFT ....  read more

Review of the State-of-the-Art in Coal Blending for Power Generation

The review has considered the available information on coal blends from two points of view -firstly, coal properties and their additivity and secondly, the performance of blends in pulverised fuel (pf) firing. The review has concluded that the level of understanding on properties ....  read more

Ash Behaviour in Coal-Fired Furnaces: Technology Review

This project conducted a state-of-the-art review of ash behaviour, in terms of the ability to predict slagging and fouling, either by comparison with other coals, or for a given coal fired in a given pf fired power station, and the ability to trouble-shoot slagging problems and to establish ....  read more

NOx Formation: Technology Review

The prime objective of project C9056 was to provide the coal industry with an understanding of the current state of knowledge about NOx formation during PF combustion. In doing this the study aimed to:

a) Clarify current understanding of the separate influences of coal ....  read more

Management of Trace Elements in Ash Dams

This project was undertaken to make an assessment of the practicality of "alternative" strategies to manage trace elements, in particular, arsenic, boron, molybdenum, selenium and vanadium in ash dams. These elements form oxyanions in flyash leachates and are soluble ....  read more

Trace Element Deportment in Combustion Processes

Coal combustion is an important anthropogenic source of semi-volatile trace elements such as As, Hg, Cd, Se, Pb and Zn to the environment. These emissions are of significance because of potential environmental impacts on human and ecosystem health.

These metals are known to be ....  read more

Prediction of Ash Phase Equilibria using FACT Models

The behaviour of mineral matter at high temperatures in coal utilisation technologies is a major issue that influences coal value, marketing and resource utilisation. A wide variety of phenomena, such as the formation of slagging and fouling deposits in pf combustion, agglomeration in ....  read more

Relating Coal Properties to Ash Deposition & Slagging: Tools for Investigation of Deposit Samples

Several theoretical and analytical tools to characterise ash-related problems in pf boilers, including slagging, fouling, erosion and heat transfer, have recently been developed. This study details the evaluation of these tools, particularly in distinguishing the impact of coal properties, ....  read more

Review of Trace Elements in Coal

Coal contains a wide range of trace elements, predominantly associated with the various minerals which are the constituents of the inorganic matter. The mineral matter is the precursor of the ash formed during combustion.

Many trace elements present in coal are ....  read more

Leachability of Trace Elements from Coal Stockpiles

The aim of this project was to study the leachability of environmentally sensitive trace elements from stockpiles of Australian thermal coals and to address the concerns that have been expressed by some overseas purchasers (in particular Japanese power stations). Although there is no evidence ....  read more

Influence of Coal Particle Size Effects on Pf Combustion Plant Performance and Efficiency

Within Europe, regulations have been introduced that reduce acceptable levels of dust emissions from coal-fired plant.  Such emissions are influenced by a number of factors, but one of the main contributors is carbon in ash.  Furthermore, plant operators are required to ....  read more

Background Information for Web Site on Trace Elements in Coal

The aim of this project was to develop a website that contains the essential information on the environmentally sensitive trace elements in Australian bituminous thermal coals and provides a comparison of the concentrations in the Australian coals with those of other thermal coals  ....  read more

Fracture Toughness as a Replacement for Hardgrove Grindability Index

The Hardgrove Grindability test is used to determine how well a particular coal will perform in a coal pulverizer. It is also used commercially as a limiting value property in coal specifications. Inadequacies in the standard test have been recognized for some time and various modifications ....  read more

An Improved Grindability Test

The Hardgrove Grindability Index test, developed in 1932, is universally used in specifications for coal purchase and power station pulveriser design, to indicate the grinding properties of coal and other commodities. It has, however, three deficiencies:

• it uses only

Determine and Verify Available Emission Data and to List the Areas Lacking Data on Air Emissions from Industrial Black Coal Fired Boilers in Australia

The Commonwealth Government requires that all Australian fuel users regularly report emissions from their fuel burning plant. These reported results then enter the public domain and are available to all interested parties. This means that Australian industrial users of coal are required ....  read more

Heat Transfer Behaviour of Australian Coals

The aim of this project was to study the leachability of environmentally sensitive trace elements from stockpiles of Australian thermal coals and to address the concerns that have been expressed by some overseas purchasers (in particular Japanese power stations). Although there is no ....  read more

ESP Performance of Australian Coals

Electrostatic precipitation is currently the most common method applied throughout the world for collection of fly ash from power station boilers. Electrostatic Precipitators (ESP) are available in capacity suitable for the largest boilers, are relatively cheap to construct, may achieve very ....  read more

Accurate Instrumental Determination of Carbon in Coal

Traditionally, thermal coal has been traded with its value being primarily determined by calorific value as well as properties relevant to particular customers (such as grindability and slagging/fouling behaviour). With the need to estimate greenhouse gas emissions and the possible ....  read more

Effect of Sodium Dosing on ESP Performance - Parts 1 and 2

PART 1 REPORT

Fly ash resistivity is an important characteristic in regard to collection of coal ash in an electrostatic precipitator (ESP). Where the resistivity is excessive the ESP can exhibit symptoms of back corona. This can lead to excessive dust ....  read more

Predicting Pulveriser Performance

This project aims to demonstrate that the Hardgrove Grindability Index (HGI) coupled with standard Petrographic Analysis can be used to greatly improve the prediction of mill power requirements, mill throughput and product size distribution using existing data generated in a pilot scale ....  read more

Milling of Blends

Evaluating the potential performance of coal blends in both the thermal and PCI market requires knowledge of the size distribution of the organic and mineral matter components of a blend, especially when there are significant differences in the HGI of the component coals. The size ....  read more

The Improved Grindability Test: Comparisons with HGI

The Hardgrove Grindability Index test, developed in 1932, is universally used in specifications for coal purchase and power station pulveriser design, to indicate the grinding property of coal and other commodities. It has, however, three deficiencies:

• it uses only the

Maintenance of Database on Trace Elements in Australian and Internationally Traded Thermal Coals

The international market in thermal coals for power generation is highly competitive and is largely driven by quality and cost. Environmental issues are however attracting increasing scrutiny because of stricter controls on the release of trace elements to the environment through air emissions ....  read more

Effect of Iron Dosing on Boiler Performance

The combustion chamber of a pulverised coal fired boiler is designed to accept a range of heat transfer rates. However, should the heat transfer with a particular coal deviate from a range set by the control mechanisms on the boiler, then operational problems can be experienced with ....  read more

Options for Upgrading the ACIRL Pilot Combustion Facility

For about twenty years the pilot-scale combustion test facility run by ACIRL at Riverview Queensland has provided a service to the coal industry, whereby the performance of coals in pulverised-fuel fired power plant is simulated. This service enables coal producers and users to evaluate ....  read more

Impacts of New Legislative Controls on Mercury Emissions on Markets for Australian Coals

Recent international developments have led to a very careful examination of mercury emissions to the environment.  Inevitably developments such as these will focus attention on mercury emissions from coal combustion. Mercury is present in small concentrations in coal, but the large ....  read more

QEMSCAN for Characterisation of Coal and Utilisation By-Products

QEMSCAN is an automated electron beam image analysis technique, originally developed by CSIRO, Division of Minerals and now by a CSIRO spin-off company Intellection Pty. Ltd., which has been widely applied in the minerals industry. However, its use in the coal and related industries has been ....  read more

Environmental Assessment of Thermal Coals

The environmental impact of trace elements during coal combustion relates to their emissions to air and water. Operators of power plants are required to conform to environmental standards through legislated statutory limits and operating agreements. The assessment of potential environmental ....  read more

Trace Element Speciation and Deportment: A Review of Current Status and Needs

ACARP has funded an extensive program of work on trace elements, both directly and indirectly through funding provided to the CRC for Coal in Sustainable Development (CCSD). In this report this work is critically reviewed, together with relevant international research. 

Improved Grindability Test: Essential Refinements to Method

The Hardgrove Grindability Index test, developed in 1932, is universally used in specifications for coal purchase and power station pulveriser design, to indicate the grinding property of coal and other commodities. It has, however, three deficiencies:

• it uses only the

Maintenance of Trace Elements Database

The international market in thermal coals for power generation is highly competitive and is largely driven by quality and cost. Environmental issues are however attracting increasing scrutiny because of stricter controls on the release of trace elements to the environment through air emissions ....  read more

Measurements of Mercury Speciation From Combustion of Australian Coals

Mercury is a naturally occurring metal and there is ample evidence that mercury emitted in industrial areas is transported globally. The UNEP Global Mercury Assessment concluded that there was sufficient evidence of global adverse impacts and that these warranted initiation of actions to reduce ....  read more

Maintenance of Database on Trace Elements In Internationally Traded Thermal Coals

Background

Increasing concern about the environmental impact of trace elements from the utilisation of coal for electricity generation has focused attention on the levels of environmentally sensitive trace elements in thermal coals. Australia is one of the major suppliers to the ....  read more

Measurement of Submicron Ash Emissions and Associated Trace Elements From A Pilot-Scale Boiler Simulation Furnace

Concerns about the health effects of solid particulate emissions from coal fired power plants have recently focussed on the fine or sub-micron particles.   The potential health effects of these particles when inhaled are exacerbated by the presence of toxic trace elements, many of ....  read more

Coal Quality Testing of Six Coals in a Pilot Scale Combustion Facility Upgraded to Simulate Modern Power Station Capabilities

The Australian export thermal seaborne coal market has grown significantly over the last 25 years and apart from the growth of the market, there have been a number of significant developments in the industry over the last couple of decades.  Technology utilised by end users of Australian ....  read more

The Minamata Convention On Mercury Implications And Responses For The Coal Industry

The objectives of this ACARP project were twofold:

· To produce regular briefing documents for ACARP on the development of a global mercury treaty; this report is the fourth and final of these documents;

· To facilitate Australian expert involvement in the Global Mercury ....  read more

Review of ACARP Research to Support Marketing of Australian Thermal Coal

In this project, researchers pinpointed issues relating to the use of Australian thermal coals, identifying relevant research and Australian capabilities for thermal coal marketers, to assist the development of the ACARP Technical Market Support Committee's research priorities. Researchers ....  read more

Slagging and Fouling in HELE plants: Assessment of Fusibility and Particle Size in Deposition

Key markets for Australian black coal have been moving to supercritical and ultra-supercritical plants, often referred to as HELE boilers, which operate at higher steam temperatures. Increased steam temperature means increased fire-side temperatures. Additionally, most countries are ....  read more

Combustion Characteristics of Australian Export Thermal Coal Using Advanced Imaging Techniques

During pulverised fuel combustion, coal particles are rapidly pyrolysed to yield char particles which are then burnt. The conversion of coal particles to char is the rate determining step of the coal combustion process. For a single coal, the individual coal particles can vary significantly in ....  read more

A 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 coal fired power plants that are capable of operating at higher steam temperatures and pressures to achieve higher plant efficiencies. These efficient units use low-NOx coal burners and are fitted with state-of-the-art ....  read more

Characterisation of Complex Coal Blends, and Methodology to Investigate Thermal Coals Based on Compositional Analysis

This project built on the outcomes from project C25049 (Fusibility of Coal Blends and Minerals in Coking coal) which successfully used Coal Grain Analysis (CGA) to characterise simple binary and tertiary coking coal blends and provide information on the maceral and grain type abundances for ....  read more

Development of a Combustibility Predictor for Thermal Coal Utilisation in Pulverized Fuel Boilers

Coal is a heterogeneous material, consisting of a range of carbonaceous matter and a variety of minerals. Each particle is different from the next, and because of its diversity, each particle behaves differently during combustion. Coal in general is talked about in terms of averages or totals, ....  read more

Mineral Re-Distribution from Raw Coal to Pulverised Fuel (pf) Coal to Ash in Commercial Power Stations

This project was based on understanding how minerals in thermal coal are redistributed during combustion in commercial power stations. The project involved samples taken from two Australian power stations burning the same coal. Samples of pulverised coal and fly ash were obtained under a range ....  read more

Optimisation of Co-firing selected Australian Thermal Coals with Biomass and International Coals

The chemical and physical composition of biomass presents many technical challenges, but it has been shown that with correct fuel choices and thorough optimisation of existing infrastructure, many of these can be overcome whilst cofiring small percentages without large capital investment. ....  read more

Strength Development in Fouling Deposits

When coal is combusted in a boiler, the fly ash that is produced flows with the hot gases through the radiant and convective zones before it is removed. About 10% of the ash collects on the walls and pendant tubes. If this ash is not removed it forms a thick layer that limits the heat transfer ....  read more