Technical Market Support

A Fractographic Approach to Understanding the Mechanisms of Coke Breakage

The prediction of strength of coke produced from a coal (either singly or in a blend) is a key input into valuing the coal. Current models are largely empirical and often fail when used for coal with properties outside the data used to develop the model. This project aims to take techniques ....  read more

Abradability of Australian Cokes

The Surface Breakage Rate Constant (SBRC) is an index of coal quality derived from tumbling coke in a conventional drum but with continuous removal of the fines. SBRC has been thought to be related to the tensile  ....  read more

Alternative Method for Assessing Coking Coal Plasticity

Traditional plasticity measurements for coal have a number of limitations associated with the reproducibility of the tests and their use in predicting coking behaviour. This report reviews alternative rheological methods for characterising the plastic behaviour of coking coals. It reviews the ....  read more

An In-situ Study of the Plastic Layer Formation in Coking Coals Using a Lab-scale Test Furnace

The main objectives of this project were to investigate:

• Formation, migration and characteristics of the plastic layers of Australian coking coals during coking (in-situ);
• Improved understanding of the chemistry and formation mechanism of plastic layer and its impact

Assessment of In Situ High Temperature Strength of Cokes

The research for this project was undertaken in three stages.

Stage I established a reliable and repeatable process for mechanical testing at high temperatures using facilities at ANSTO. Three cokes were tested in Stage I and II. In Stage I, high CSR coke samples displayed ....  read more

Australian PCI Coals Under Industry Scale Conditions Ironmaking Blast Furnace Using 3D Computer Modelling: The Injection of Coal Blends

This project evaluated the combustion behaviour of the blends of Australian PCI coals under industry-scale blast furnaces (BFs) conditions using  improved 3D computer modelling. The work was undertaken in two stages:

• Stage 1: Single Australian PCI coals were evaluated using

Automated Optical Image Analysis of Coke Texture and Structure, and their Connection with Coke Porosity, Reactivity, Strength and Parent Coal Blend

Metallurgical coke is one of the most utilised forms of carbon used in ironmaking in blast furnace operation where it provides reducing gases, fuel for supporting the necessary temperatures and carbon for the hot metal to achieve specific properties. Strength is one of the most important ....  read more

Behaviour of Coal Injected into Molten Baths

During the past 30 years there has been a major trend in the metallurgical industry towards the use of high intensity bath smelting reactors for large-scale production of metals. Coal is commonly used as a fuel and/or reductant in these reactors.

GK Williams Cooperative Research Centre ....  read more

Behaviour of Coke Mineral Matter in the Blast Furnace

A previous ACARP project (C14074, Coke Mineral Matter Reactions) presented the results of a study of the role of mineral matter and mineral matter reactions in the degradation of coke through their influence upon coke reactivity and coke strength.

The results of the study ....  read more

Carbon structure transformation during coking of Australian coking coals: Better understanding the coke formation

Carbon structures of coke that are formed during the plastic layer and the semi-coke stage determine the coke strength and reactivity. So far, in the open literature, the evolution and transformation of carbon structures during coking processes and the correlation between the carbon structure ....  read more

Carbonisation Heat Transfer Predictive Capability

The objectives of this project were to:

• Develop an enhanced model of heat transfer in a slot type coke oven, based on the fundamentals of heat transfer and using a predictive model of thermal properties of the charge, based on the composition of the coal

Characterisation of Australian and Indian Coals and their Cokes from Stamp and Top Charged Coke Ovens

Due to strong demand and declining reserves of premium coking coals, new coal reserves are being developed, which are often perceived to be of low premium on the basis of relatively lower coke strength after reaction (CSR) values. In India and China, low premium coals have been used in coke ....  read more

Characterise Cokes for Strength and Reactivity - Stage Two

To better understand how coal transforms into coke requires the ability to relate the main microstructural and microtextural features of the coke to properties of the coal. This project aims to identify the influence of these features on coke quality.

There are two parts to ....  read more

Characterising the Degradation of Cokes Made from Australian Coals and Subjected to Simulated Blast Furnace Operating Conditions

Stage 1

The key objective of the first stage of this project was to develop a bench-scale methodology for the evaluation of coke quality under the blast furnace (BF) ironmaking conditions. To achieve this objective, BF conditions were simulated by the gasification of coke with ....  read more

Coal Characterisation for PCI

A technical review has been undertaken on coal characterisation of Pulverised Coal Injection (PCI) with the aim to prioritise research areas where Australian research organisations can make a significant contribution to the understanding of the impact of coal characteristics on PCI. ....  read more

Coal Dilatation

There are various national and international standards for Coal Laboratories to use for the Dilatation test.  The results reported vary depending on which standard is used which causes issues when results are used at an international level and particularly relevant to coal sales ....  read more

Coal Fluidity, Stockpiling and Coke Quality

One perception in the marketplace is that coking coal quality decreases during transport and stockpiling due to ageing. This ageing is often estimated using plasticity measures with the assumption that plasticity is an indicator of coal oxidation and, therefore, an indicator of potential ....  read more

Coal Swelling and Flowability as a Measure of PCI Lance Blockage Propensity

As efforts to improve the efficiency and reduce costs of the blast furnace continue, increased effort to increase the amount of pulverised coal injection will occur. With increasing injection rates, the pressure to control coal character and the quality of other components increases. One of ....  read more

Coke Reactivity and Characterisation

Coke quality in the blast furnace is measured by its resistance to degradation. The roles of coke as a fuel and as a reducing agent are not limiting factors in terms of blast furnace performance. However, the role of the coke as a permeable medium is crucial in economic blast furnace ....  read more

Coke Reactivity Test: Critical Parameters

A Draft International Standard ISO/DIS 18894 has been prepared titled "Coke - Determination of coke reactivity index (CRI) and coke strength after reaction (CSR)". The technical committee has the role of standardising common practice. The Australian members of that committee do not have ....  read more

Coke reactivity with CO2 and H2O and impacts on coke microstructure and gas diffusion

With the global shift to low-carbon ironmaking, partial substitution of coke and PCI with hydrogen in the blast furnace is one of the most promising blast furnace decarbonising solutions. In a hydrogen-enriched blast furnace, injected hydrogen reduces the ferrous burden while generating ....  read more

Coke: Its Constitution and Utilisation

Coke made in coke ovens from coal and used in iron blast furnaces is a strategically critical manufactured product for contemporary and future world iron production. The important physical, chemical and microscopic properties of cokes are examined and explained, drawing on both an exhaustive ....  read more

Commissioned Study on PCI Research and Future Directions

This commissioned review examines the current status and future directions for pulverised coal injection (PCI) into blast furnaces used in the production of pig iron. It has been undertaken to assist the Australian coal industry to identify possible future industry funded research. This ....  read more

Concentrating Coke Oven Sized Inertinite-rich Particles to Study Their Behaviour in Targeted Coking Blends

Previous ACARP projects C24055 and C24059 showed that the water-based reflux classifier can successfully separate coal maceral concentrates without using dense media. Coal particles for maceral separation on these projects varied from 0.04-0.5 mm, while separating maceral concentrates using ....  read more

Correlating the Distribution of Multiscale Structural Features with Coke Quality Indicators by Combining Advanced Datamining Approaches with 3D Visualisation

This project builds on a number of recent projects that have helped understand the link between the distribution of coke microstructure and coke strength, reactivity and the formation of the microstructure in the plastic layer. It builds directly on a previous project (C27036) that integrated ....  read more

Design a Test Energy Recovery Coke Oven

The objective of the study was to develop a concept design for a test non-recovery coke oven, which was required to be relocatable.

The report summarises available knowledge on full scale ovens, the development of estimates for missing information, and the development of ....  read more

Determination Of A Theoretically Based Coke Strength Index Or Indices Based On Drum Tests

Coke quality is commonly characterised by tumble drum strength tests, typically on coke produced in pilot scale coke ovens. The empirical nature of the commonly used suite of tests usually requires that all the major coke tests need to be completed for a single coke. Additionally, the ....  read more

Determine The Relationship Between Roga Test Results And Caking Index Results For Australian Coking Coals

This project was aimed at exploring critical factors of the Roga and Caking Index, investigate the appropriateness of the precision parameters outlined in the two standard methods, confirm that a relationship between Roga and Caking Index exists for a range of Australian coking coals and use ....  read more

Development of a Method to Compare Chemistry vs Structure Effects of Fusible Inertinite in Coke Making

Coking coal quality is based on a number of indices which characterise the quality of the coke product. Many standard tests exist to compare the parent coals; the resulting evaluations, however, do not always reflect accurately the real behaviour of the coals during the coking process. Using ....  read more

Direct Imaging of Carbon-dioxide Penetration in Cokes Pre- and Post-reaction

The suitability of carbon coke for use in a blast furnace is determined by a range of factors other than composition such as strength and reactivity, both of which are critically dependent on the coke microstructure. To improve the ability to predict coke behaviour through a better ....  read more

Effect of Blend Characteristics on the High-Temperature Strength Evolution and Relevant Mechanisms in Cokes

Coals are blended to overcome the increasing scarcity of high-quality coal and coke resources. The resultant properties of blended coals are not always a proportional sum of the starting blend constituents, which makes it difficult to predict the degradation under reactive conditions and at ....  read more

Effect of Coke Properties on High-Temperature Strength and Hot Metal Reactivity Under Blast Furnace Conditions

This project focussed on investigating the differences in characteristics of cokes prepared from single coals and blends (binary and ternary) in terms of their behaviour for blast furnace ironmaking. Two single coal derived cokes (D and H) and two blended coal derived cokes (C1 and C2) were ....  read more

Effect of Coke Reactivity upon Coke Strength with Focus on Microstructure

The primary aim of this project was to examine changes in the microstructure of metallurgical coke during high-temperature reaction with CO₂.  Additionally, the project aimed to relate the changes in microstructure to the quality of coke, in terms of its reactivity and strength. ....  read more

Effect of Parent Coal Origin on Coke Quality by Studying Structural and Textural Differences between Cokes made from Similar Australian and Northern Hemisphere Coals

This project focussed on revealing differences between textures and structures of Northern Hemisphere and Australian cokes made from coals with similar rank (RMax) and amount of vitrinite.

To perform the project, 19 coke samples made from single coal, made from Northern Hemisphere ....  read more

Elucidation of the Effects of Minerals on Coke Behaviour in the Blast Furnace

The objectives of this project were to determine whether minerals in coke have an effect on hot coke strength, and if so, elucidate the mechanism(s) by which this occurs under blast furnace conditions. A secondary objective was to demonstrate the use of the Environmental Scanning Electron ....  read more

Estimating the Fusible Content of Individual Coal Grains and its Application in Coke Making

For coals of suitable rank the vitrinite, liptinite and some of the inertinite macerals are fusible during coking and the minerals and remaining inertinite macerals do not fuse. The amount of fusible inertinite present in a coal varies between coals extracted from differing coal basins and even ....  read more

Evaluation of Australian PCI coals in the co-injection of coal and hydrogen into blast furnaces using a 3D computer model

This project aimed to determine whether the co-injection of coal and H₂ can enhance the combustion performance of Australian PCI coals in ironmaking blast furnaces (BFs) using Computational Fluid Dynamics (CFD) modelling. It was of particular interest to assess the impacts of ....  read more

Evaluation of Australian PCI Coals Under Industry Scale Blast Furnace Conditions Using 3D Computer Modelling – Stage 3: Under Overseas Blast Furnace Conditions

This project evaluated the Australian PCI coals under industry scale blast furnace (BF) conditions using an improved 3D Computational Fluid Dynamics (CFD) model. In Stage 1 (C26041), the single coal injection of a range of Australian PCI coals was evaluated using a 3D PCI model under ....  read more

Evolution of the Pore Structure in Coke and Implications on Coke Strength

This project has focused on the evolution of the pore structure in coke during resolidification as pore structure plays a key role in the strength properties of the coke.  It is known that the porosity of the plastic layer can be very high and that soon after the porosity plummets as the ....  read more

Extension of a Theoretically Based Coke Strength Index to Small Scale Coke Oven Samples and Adhesion Controlled Cokes

Assessment of increasingly subtle changes in coal quality, either potential improvements or deteriorations, is clouded by the deficiencies in drum tests routinely conducted on pilot scale coke. When coking tests are performed on coke produced at the small scale (8kg feed coal) the comparison ....  read more

Factors Affecting Coke Size and Fissuring during Cokemaking

The literature on the mechanism of fissuring during coking was reviewed and alternative approaches to the modelling of the fissuring mechanism evaluated. A new mechanism and model for the physics of fissuring was proposed. The model incorporates:

Factors Affecting Coke Size and Fissuring During Cokemaking Part 2

This work addressed the mechanism of fissuring during metallurgical cokemaking and extends on a previous ACARP project. Considerable progress has been made in understanding the mechanism by an integrated modelling work / experimental program. The work points to opportunities for controlling ....  read more

Factors Underpinning the Gasification Reactivity of Coke RMDC and IMDC with CO2

It is well known that the gasification reactivity of metallurgical coke is inversely correlated with its strength. The reactivity of coke is a key contributory factor to its integrity in the ironmaking blast furnace. Previous studies have generally indicated that under CSR test conditions, the ....  read more

Fine Particles from Coal Combustion

When coal is combusted in a power station, the resulting ash material is produced in a wide range of particle sizes and chemistries.  The finest ash particles are typically labelled as PM10 and PM2.5, i.e., particles less than 10 and 2.5 µm in size, respectively.  PM10 and PM2.5 are ....  read more

Fundamental Reasons For Different Coking Behaviour Of Coals From Different Basins - Behaviour Of Semi-inerts

Coking coal quality is based on a number of indices which characterise coke quality. While a number of standard tests exist to compare coals, some have well known flaws and are often designed to determine coal value rather than reflect real behaviour on a coke oven. In the case of coals from ....  read more

Fusibility Assessment for Coal

The aim of the project was to calibrate the CSIRO scanning fluorescence laser microprobe (SLFMP) against the results of coal-to-coke mass balance calculations to provide a rapid and inexpensive method of assessing the proportion of fusible macerals in single seam coals and blends. In the ....  read more

Fusibility of Coal Blends and Minerals in Coking

The CSIRO optical reflected light imaging CGA (Coal Grain Analysis) system was developed and enhanced with ACARP support to provide compositional information on individual coal grains for many studies across the coal chain from exploration and processing to utilization, and including ....  read more

Fusion of Coking Blends

The results from a previous ACARP project, "Improved Laboratory Methods to Evaluate Properties of Coking Blends", provided the first direct evidence that when blends of some coals were heated, the coals interacted in a way that affected the extent to which the blends fused. ....  read more

Gasification Kinetics of Coke Lumps under Simulated Conventional and H2-Rich Blast Furnace Processes

The introduction of hydrogen-rich fuels into blast furnace (BF) is identified as a promising approach to reducing the carbon footprint of ironmaking. In this process, injected hydrogen promotes the indirect reduction of the ferrous burden generating excess H2O in the process. Partial ....  read more

High Rate PCI and the Interaction with Coke Quality

This substantially experimental study was aimed at investigating the interaction of coke with pulverised coal, under conditions configured to simulate coke at the back of the raceway of an ironmaking blast furnace under a regime of high rate pulverised coal injection. In the test rig used for ....  read more

High Resolution Micro-CT 3D Assessment of Coke Gasification

Coke reactivity index (CRI)/coke strength after reaction (CSR) measurements are considered key metrics of coke quality and performance in a blast furnace. Improved knowledge of the reaction interface/contact area between the gas and coke and the mineral matter and coke is needed to apply CRI ....  read more

High Temperature Tribological Testing of Coke Coupled with 3D Visualistion to Enhance Understanding of Coke Breakage and Link to Parent Coals

This project applied the approach developed during ACARP project C27017 “Influence of Elevated Temperature and Gas Atmosphere on Abrasion and Interface Properties in Blast Furnace and Pilot Oven Cokes” to examine coke abrasion resistance in-situ at temperatures of up to ....  read more

Imaging Gas Penetration Inside Coals and Cokes and Determining Influence on Coke Reactivity

The suitability of cokes for use in a blast furnace is determined by a range of factors such as strength and reactivity, both of which are critically dependent on the coke microstructure.  The objective of this project was to improve the ability to predict coke behaviour through a better ....  read more

Impact of Co-Injecting Hydrogen and Australian PCI Coals on Overall Blast Furnace Performance Using a Heat and Mass Balance Model

This project aimed to evaluate the impact of the co-injection of Australian PCI coals and hydrogen on overall blast furnace (BF) performance using a Heat and Mass Balance (HMB) model which is available directly from UNSW via the email below.  The model will be used to assess several key ....  read more

Impact of Milling Techniques on Coke Oven Feed

The international export market for Australian coals is dominated by coking coal sales. However, few Australian coking coal producers process their coal domestically to produce direct coke oven feed. Therefore there is little understanding of how best to prepare each coal to achieve optimum ....  read more

Impacts of plastic layer permeability and internal gas pressure on the formation of coke microstructure and coke qual

This project utilised advanced techniques developed in previous project C29068 to explore the impact of internal gas pressure (IGP) and plastic layer impermeability (PL impermeability) on the microstructure evolution from the plastic layer to the final coke structure. Observations were ....  read more

Implications of Coking Conditions on CSR

Coking is one of the main contributors to the quality of the resultant coke and therefore will influence the CSR of the coke. Laboratories worldwide use their own devised methodology for coke making, which is cause for concern since CSR results cannot be compared without a measure of error. ....  read more

Improved Laboratory Methods to Evaluate Properties of Coking Blends

A range of Australian coking coals were blended and their behaviour during carbonisation examined to see if their fusibility was affected by interactions between ....  read more

Improved Measurement of Handleability for Quality Control of Australian Coals in PCI and Carbonisation Applications

The aim of this project was to develop a technique by which the handleability of Australian coals in pulverised coal injection systems for blast furnace applications can be more reliably predicted and compared with other international coals on an equal footing. 

Improved Understanding of Coal Exploration Samples by Coal Grain Analysis

Over the past six years, CSIRO has used optical imaging and Coal Grain Analysis (CGA) to obtain and use compositional information on individual coal grains for studies on product coals, raw coals and tailing samples. The output from a CGA measurement provides a reflectance fingerprint on the ....  read more

Improved Understanding of Coke Quality Using 3D Immersive Visualisation and Statistical Characterisation of Microstructure Properties

This project carried out an explorative study into the use of a 3D visualisation tool to help design spatial statistics related to the clustering of microstructure and high stress locations in coke. The points used in the analysis were generated from an existing stress model and from two AI ....  read more

Improving 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 understand and characterise the 3D distribution of coke microstructure and the link to coke strength, reactivity and the formation of the microstructure in the plastic layer. This project improves the fundamental ....  read more

Improving Understanding of the Factors that Contribute to Thermoplasticity during Cokemaking and Laboratory Carbonising Tests and Impact on Coke Strength

This project encompassed two key components:

• Development of inertinite analogues to investigate the link between inertinite attributes and the development of coke strength attributes, and
• Investigation into whether laboratory carbonising test results reflect the

Inertinite Fusibility Determination

The aim of this project is was to develop a simple tool that allows the determination of the fusibility of inertinite in Australian coals.   The first step in determining the fusible inertinite component is to convert the petrographic analysis to a mass basis. This requires ....  read more

Influence of Coal Blending on Coke Nanoporosity and CO2 Reactivity

Reactivity of coke is one of the most important parameters that defines coke quality. Parameters such as nanoporosity and catalytic mineral matter also control coke reactivity. If coke nanoporosity can be controlled to any extent through coking conditions and blend composition, it would give ....  read more

Influence of Elevated Temperature and Gas Atmosphere on Abrasion and Interface Properties in Blast Furnace and Pilot Oven Cokes

This project developed a novel approach using rotational tribology testing to investigate the mechanical properties and abrasion resistance of the coke reactive maceral derived components (RMDC), inertinite maceral derived components (IMDC), and the interfaces between these two phases, at room ....  read more

Influence of Inertinite and Volatile Release Characteristics on Viscosity Development and Fusibility During Coking

This project builds on previous projects aimed at understanding the nature of interactions between inertinite and vitrinite. Prior research on Rangal coals (vitrinite reflectance 1.2%) found that mixtures of inertinite and vitrinite had lower viscosities and volatile release rates than ....  read more

Influence of Organic Liquids on Coal Carbonisation Properties

A two-stage study was undertaken to establish what effect, if any, perchloroethylene has on the coking properties of coal. In Stage 1, the fluidity of 5 samples of a high fluidity coal (Illawara coal measure, mid-high rank) was studied over a 64-week period. Samples A, C, D and E were stored ....  read more

In-situ Investigation of Coke Structure Formation Under Stamp Charged Coking Conditions

Stamp charged cokemaking has emerged as an effective technique to improve the quality of coke produced from weakly coking coals or blends of premium and low quality coking coals. Stamping can be used to either improve coke quality of poorly coking coals or allow the introduction of inferior ....  read more

In-situ study of the permeability of the plastic layer of Australian coking coals using an advanced permeability test apparatus

This project aimed to develop a new advanced permeability measurement device, and an additional feature to the 4kg coke oven at the University of Newcastle to establish a methodology for the measurement of in-situ plastic layer permeability during the coking of Australian coals. Significant ....  read more

International Comparison of Inertinite Reflectograms and Fluorograms

Inertinite is generally perceived to be a troublesome group of coal minerals, mainly because of the variable reactivity of its members in reference to most industrial processes. Although several Australian export coals contain large amounts of inertinite, their technological performance ....  read more

Investigation of the Links Between Microstructure Development in Softening Coal and the Characteristics Controlling Coke Quality

In an earlier project (C23048) computed tomography determination of three dimensional structure of coke was developed as a tool for understanding the impact of coke microstructure on coke strength. This project provides insights for the development of improved prediction of the coking ....  read more

Investigation of the oxidation rate in reducing coking propensity of individual maceral grains residing naturally in lump coal using FTIR microscopy

The mechanism of coal oxidation has been studied by various researchers due to its importance towards coal utilisation and commercial implication. Changes in the coal technological properties are normally acquired to assess its behaviour during pyrolysis either as an individual or as a ....  read more

Links Between Microstructure Development in Softening Coal and the Characteristics Controlling Coke Quality

The goal of this project was to obtain an understanding of the microstructural features in coke responsible for its strength and elucidate the mechanisms involved in the formation of those features. To achieve this goal a number of tools were developed and used in combination. Micro-CT analysis ....  read more

Literature Survey on Non-Recovery Coke Ovens

The aim of the project is understanding the coal quality and operational factors which affect coke quality in non-recovery coke ovens and to investigate means of ameliorating inferior coking behaviour.

Coke is primarily consumed by the steel industry where it is the principal fuel ....  read more

Measurement Of The Plastic Properties Of Coals

Part 1 - Influence of bulk density

Part 2 - Understanding the Sapozhnikov Test and factors that influence the determination of Plastic Properties

The force that a coal exerts on the coke oven walls can have deleterious effect on coke batteries if it is excessive.  The most ....  read more

Mechanistic Model for the Understanding of Sole Heated Ovens

A method for modelling sole heated ovens (SHO) based on fundamentals of heat transfer, particle dilatation and gas flow has been developed. It has been successfully applied to the Sapozhnikov SHO and University of Newcastle (UoN) SHO. The model estimates both the shrinkage and plastic layer ....  read more

Mechanistic Model of Coke Development in a Coke Oven Situation

The standard approach to evaluate the potential of coals or blends to create good quality coke is to use laboratory tests (dilatometer, plastometers, sole heated ovens etc). However these tests have limitations. This project combined the various approaches into a 'whole of oven' model ....  read more

Micro-CT based characterisation of the IMDC-RMDC interfacial interaction in blends of Australian and international coals

The key aim of this project was to characterise the IMDC-RMDC interface quality for a range of interactions between different coals, using a quantitative measure from 3D non-destructive micro-CT images. The measure used is the excess porosity, which is large when there are high porosity ....  read more

Microstructure Variability in Coke and its Effect on Coke Properties

The objectives of this project were to:

· Obtain micro-CT images of the microstructure of various cokes;

· Use the microstructure information to estimate strength and reactivity properties of the cokes using a finite element approach;

· Compare the estimated ....  read more

Mineral Matter Reactions in Cokes

Some cokes appear to be particularly susceptible to weakening in the blast furnace. A mechanism which has been postulated to explain this is silica reduction by coke. Theoretically, silicates could react with the coke at high temperature to produce silicon carbide and carbon monoxide with the ....  read more

Mineralogy Effects on the 3D Porosity Evolution of Coke and Coke Reactivity

CRI/CSR CO2 combustion data are key metrics of coke quality and performance in the blast furnace. Recently adapted 3D analysis techniques applied to coke and a new laboratory tool, the coke analogue, offer opportunities for generating an improved understanding of CRI/CSR coke gasification that ....  read more

Nanoporosity in cokes: their origin, control and influence on CO2 reactivity

This project using the outcomes of previous project C24060, examined how the total, closed and open porosity of cokes is affected by partial gasification of the coke and how this varies with pore size. Because maceral composition is believed to be important in predicting coke reactivity, we ....  read more

Optical Image Analysis of Coke Structure and the Effects of Structural Parameters on Coke Strength

Understanding of coke strength and its dependence on original coal blend parameters is one of the major technical marketing support tasks required to improve prediction of the performance of coals and blends during coking.

This project applied novel structural identification and ....  read more

Optimisation of the Gieseler Fluidity, Dilatation and Crucible Swelling Number of Australian Coking Coals

Crucible Swelling Number, Audibert-Arnu dilatometer and Gieseler plastometer residua were collected for a range of Australian coals. The samples were examined at the optical microscope and hand specimen level, to understand the processes that influenced the results. This was with an aim to ....  read more

PART A - Development of a Drop Tube Furnace based PCI combustion test & PART B - Review of International PCI Test Rigs

The aim of this project was to assess the suitability of drop tube furnaces as a tool for assessing coal combustibility for use in pulverised coal injection (PCI) into blast furnaces. Drop tube furnaces (DTF) are far less expensive than pilot scale PCI rigs, they are reliable and available at ....  read more

PCI - Impact of Blast Furnace Operation

The objective of this report is to review the literature on the impact of high coal injection rates on blast furnace performance and summarise the issues faced by blast furnace operators, current trends in addressing these issues and the likely future requirements for PCI coal.

Physical and Chemical Interactions Occurring During Coke Making and their Influence on Coke Strength

This project contains a study on the interactions occurring between coal macerals from single coals and between the macerals from different coals in blends. The goal was to detect interactions and to determine their nature, i.e. whether they occur through physical or chemical mechanisms. To ....  read more

Physical and Chemical Interactions Occurring During Cokemaking and Their Influence on Coke Strength

This project builds onto a previous project , C24055 in which macerals were separated and then reblended in order to identify whether any interactions were occurring between vitrinite and inertinite. There were strong signs that inertinite can either trap or aid volatile release which affects ....  read more

Predicting Dilatation Of Coal Blends From Models Of Softening, Bubble Growth And Gas Transport

The objectives of this project were to

· Modify/develop existing models of bubble growth and collapse within a viscous fluid, gas evolution and gas flow in porous media that represent the conditions prevailing within the plastic phase of coal;

· Use the developed model to ....  read more

Predicting the Coking Properties of Blends

Eleven Australian coals, ranging in rank from 0.74% Rv, max to 1.68% Rv, max, that are or could be used in blends were obtained. Ten blends of these coals were prepared to the same "effective" rank and fluidity values. It was demonstrated that preparing blends to a fixed effective rank and ....  read more

Quality of Stamp Charged cokes and Stampability of Coals at Small Scale

The stamp charging of coal has emerged as a widely-used, effective treatment to improve the quality of coke produced in coke-making operations. Traditionally, expensive prime hard coking coal has been used to make coke with the required properties to operate blast furnaces effectively. Through ....  read more

Quantifying The Influence That The Composition Of The Individual Coal Grains In Coke Oven Feed Has On Coke Quality

Three Australian coals from different coal measures were washed to produce a vitrinite rich fraction (VRF) and an inertinite rich fraction (IRF). Five blend samples of each coal with the same overall bulk quality and grind but different VRF and IRF grinds were produced. These blends were then ....  read more

Reactivity of Cokes with Gases Under Blast Furnace Conditions

The NSC reactivity test is often criticised for not being able to accurately predict performance of cokes in the blast furnace. One explanation commonly proposed for this lack is that the gas used in the NSC test, pure carbon dioxide, is different to the gas that coke is exposed to in blast ....  read more

Real-time Three-Dimensional In-Situ Imaging of Structural Evolution of Coal During Coke Making Process Using Adaptive Electrical Capacitance Volumetric Tomography

This project is concerned with the conversion of coking coal-to-coke with the primary aim of developing a deeper understanding of the evolution of the plastic (fluid) layer during the coking process using a new non-intrusive and non-optical imaging technique known as Adaptive Electrical ....  read more

Relationship between Internal Pressure and Coke Strength and Implications for Semi Soft Coking Coals in Blends

The development of new coking coal resources around the world and the changing coal quality from existing resources will require steel producers to examine new blend options for the feed to their coke ovens to maintain coke quality. The value of a coal depends on the contribution of that coal ....  read more

Relationship Between Internal Pressure and Coke Strength and Implications for Semi Soft Coking Coals in Blends

The objective of this project was to explore the relationships between the expansion and contraction behaviour of coals and blends of coals during carbonisation and then relate this behaviour to the properties of the coke produced.  Two type of coke are recognised in this project:

Relevance of Maceral Concentrates to Whole Coal Coking Predictions

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 ....  read more

Review of Coke Quality Prediction Models

This report reviews a range of coke quality prediction models, with separate sections for methods based on:

• Petrography - Schapiro and Gray, Ammosov
• Gieseler Plastometery - MOF Diagram
• Dilatation - Simonis
• Ultimate

Scoping Study: Design of Cokes from Biomass-Coal Blends for Sustainable Blast Furnace Ironmaking

There is an increasing focus on improving the environmental sustainability of the cokemaking and ironmaking processes and therefore, one possible approach to enable this is through the addition of biomass from sustainable sources as a partial replacement of coal in the cokemaking process. ....  read more

Source of Variability of Reactivity of Coke in the CSR Test

The Coke Strength after Reaction (CSR) test is used worldwide to determine the reactivity of coke. The repeatability of the Coke Reactivity Index (CRI) test result as defined in the ISO18894 standard is between 2.5 and 4%, over a typical range of 20-40% of CRI. In project C12004 several ....  read more

Stage 3: A Coke Analogue to Examine the Effect of Mineralogy on Coke Reactivity

This project has had three stages.  The three stages are a series of studies, focusing on understanding the effects of mineralogy on the reactivity of metallurgical coke, by using a coke analogue material in a pseudo-CRI test. All three report stages are published as a complete set. Stage ....  read more

Structural Differences Between Coking Coals of the Sydney Basin and Other Sources

Cokes made from Australian coals of relatively low fluidity can have better strength and reactivity values than their equivalents prepared from European or American coals. Although this systematic difference is well known, it has long been an issue in contract negotiations in sales of ....  read more

Synthetic Sulphur Calibrant Method

Stage 2 (August 2014)

In this project extension, the method for determination of sulphur in coal using a synthetic calibrant was further developed and validated for suitability in an ILS.  The current SA (Standards Australia) method AS 1038.6.3.3 for Total Sulfur was modified ....  read more

The Classification and Interpretation of Coke Textures- A Literature Review

Despite the simple chemical composition of metallurgical coke, the structure is complex, consisting of a network of variously sized pores and walls of varying thickness. Adding to this complexity is the varying forms of the carbon in the pore walls which have different microproperties and vary ....  read more

The effect of coal quality on carbon products produced with alternative thermal processing – extrusion and direct casting technologies

This study has investigated two industrially relevant methods of heating coal with the goal of producing “shaped carbon” products. Thermal extrusion was assessed as a means of producing a continuous carbon material for blast furnace use as was direct casting as a means of producing ....  read more

The Effects of Ash Minerals on Coke Reactivity at High Temperatures

This was the final stage of a larger study focused on coke behaviour at high temperatures, C29077: The Effects of Ash Minerals on Coke Reactivity at High Temperatures. The research furthers the understanding and impacts of slag contact with coke on the mineralogy and carbon structures ....  read more

The Effects of Blending of Australian Coals on the Chemistry of the Plastic Layers

Coke quality is virtually determined by the chemistry of the plastic layers that are formed during coking of coals. Most of the previous research in the open literature on the underlying chemistry of the thermoplastic behaviours of single coals and blends have been carried out under ....  read more

The Strength Controlling Properties of Coke and their Relationship to Tumble Drum Indices and Coal Type

This project was carried out to address the problems of conventional tumble drum coke strength tests, which, despite their convenience, rank cokes differently and raise the question of which test best reflects the strength of coke under the breakage conditions of interest. These were addressed ....  read more

The Strength of Interfaces in Metallurgical Coke and its Influence on Coke Abrasion

This project applied tribological and scratch testing techniques to metallurgical coke samples to determine:

• The abrasive strengths of the coke textural constituents; and
• The strength of the interfaces between the inertinite maceral derived components (IMDC) and the

Thermal Study of the Coking Behaviour of Thermoplastic Coals

The objectives of this research were to apply laboratory bench-scale experiments to study the coking behaviour of Australian thermoplastic coals and correlate the results with coke tests obtained under large scale research coke oven conditions.  A novel thermoanalytical technique ....  read more

Transformation of cross-linking structures in the plastic layers during coking of Australian coals and its role in coke formation

This project aimed to:

• Characterise the transformation of cross-linking structures from the plastic layer to coke by using the 4 kg lab-scale coke oven facility and various advanced analytical techniques.
• Explore the underlying mechanisms of how the cross-linking

Understanding Coal Grain Effects On Coke Quality

The project extended the work on the application of coal grain analysis to understanding coking behaviour to two more Rangal coals. As previously coke oven charges were prepared with different coal grain compositions but the same overall grind and coal composition. The procedure successfully ....  read more

Understanding Coal Interactions in Coking Blends

• A tool that could accurately define the carrying capacity of a coal was not produced. In this regard, the program was unsuccessful. However, the program did provide sufficient information that would allow development of this tool in the future using different breeze

Understanding Cokes Performance in Blast Furnace Conditions- Coke Strength Extension

The performance of coke in the blast furnace ideally should include those properties of coke that reflect its resistance to degradation under the mechanical, chemical and thermal environment of the blast furnace. A previous collaboration between UNSW and Ruukki Works, Rahee, Finland, obtained ....  read more

Understanding Mineral Matter in Australian Coking Coals and PCI Coals

Three coking coals and three PCI coals were selected to study the effect of coking and heating coals on the minerals present. The coals were selected to cover a wide range of mineral types. A number of techniques were used to characterise the mineral matter, including:

• Powder X-ray

Understanding of the mechanisms of chemical interaction between vitrinite and inertinite

This project aimed to study the chemical interaction between volatiles evolved from vitrinite and inertinite during heating. The project hypothesised that volatile components from vitrinite may act as plasticising agents for portions of the inertinites, thereby providing a mechanism to explain ....  read more

Use of vitrinite reflectance categories on coke strength prediction of bi-modal and multi-modal coal blends

This project aimed to explore the potential use of vitrinite distribution categories (VDCs) to explain the in-situ coking behaviour and improve the prediction of CSR for coal blends. VDCs, previously developed capture the overall shape and modality of the vitrinite reflectance distribution in ....  read more

Using CGA to Investigate the links between Inertinite Fusibility and Coke Structure

Previous projects C16047 and C20008 identified some coals from different Australian coal measures exhibited a different sensitivity to fine grinding of the inert rich fraction during coking. The previous work speculated that the differences were due to different dilatation characteristics ....  read more

Using Fractography, 3D Image Analysis and CGA to Investigate the links between Inertinite Fusibility and Coke Structure in Rangal Coals

Previous ACARP projects identified that coals of different ranks from different Australian coal measures (or with different dilatation characteristics) can exhibit a different sensitivity to the grind of the inert rich fraction (IRF). Some coals showed increasing coke strength with increasing ....  read more

Using High Range Mass Spectrometry to Study the Link Between Coal Structure, Coke Strength and Thermoplastic Chemistry in Blends

This project investigated the use of Laser Desorption/Ionisation time of flight mass spectrometry (LDI-TOF-MS) as a tool for measuring molecular weight changes occurring during the development of thermoplasticity in a suite of industrial coking coals.

The study indicates that the ....  read more

Volatile Release During Pulverised Coal Injection as a Factor in Determining Combustibility

Pulverised coal injection is a valuable and important tool in producing iron in blast furnaces. Without PCI the furnace is dependent solely on the more expensive coking coal. It increases flexibility and reduces costs. However, until recently determining if a coal would be suitable for PCI has ....  read more

Washability and distribution of sulfur and trace elements for different size and density fractions of raw coals

Based on the hypothesis that the levels of sulfur and other toxic trace elements in a coal vary with particle size and density of the raw coal, this project studied their distribution in two raw coal samples to determine which size and/or density fractions of the unwashed coals should be ....  read more