ACARP ACARP ACARP ACARP
Technical Market Support

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

Technical Market Support » Metallurgical Coal

Published: August 02Project Number: C10054

Get ReportAuthor: Grant Quinn, Basim Faraj, Ruth Callcott, Tom Callcott | International Coal Consultants, Faraj Consultants, Callcott Consulting

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 Microscope (ESEM) for the study of coal and coke. The basic working hypothesis was that coking coals with minerals containing alkali, alkali earth and transition elements such as Na, K, Ca, Mg, Fe and Mn suffered detrimental effects during coking that resulted in cokes that were more reactive and lower in hot coke strength than equivalent coking coals which had low concentrations of these elements. This hypothesis was confirmed by coking two coals that had sufficiently similar petrographic composition and rank but different ash chemistry and mineralogy.

Attempts were made to simulate the reaction of coke with blast furnace gas at high temperatures in the ESEM. Operational problems showed that the instrument is not yet sufficiently developed to simulate the higher temperature blast furnace environments. However a number of possibly important observations were made, especially the formation of mineral phase globules of glass on the coke surfaces above 1217°C. It was also observed that reaction between coke and gas occurred mainly on the interpore wall material and not the pore linings. This implies that coke is consumed from the outside in and may explain why coke retrieved from the raceway of blast furnaces is a smaller version of the charge coke.

SIROQUANTTM XRD was used extensively on coals, their cokes and their coke CRI residues, and clearly showed the mineralogy of each was different. The difference in mineralogy between coke and coke CRI residue is especially dramatic and shows that there is a lot of reaction occurring within the mineral phases of coke pieces during this test. This implies similar vigorous reaction of the mineral phase within coke inside the blast furnace.

Calculations were performed with the thermodynamic computer package F*A*C*T in order to determine whether gases evolved by minerals could affect coke porosity. The results showed that gas evolved by minerals in coal can be of the order of several litres per gram. Perhaps surprisingly, the main contributors were the clays ? in this case kaolinite and illite. Not surprisingly, the carbonates were also prolific gas producers but in some cases the gas was given off during the semicoke phase. It is shown however that mineral-derived gas is negligible when compared to the volume of volatile matter produced during the plastic phase and is an unlikely cause of higher porosity and therefore higher reactivity. It is possible that gases given off after resolidification by calcite for example, could increase porosity due to micro fissuring.

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