Open Cut

Estimation of In-Situ and Product Total Moisture

Open Cut » General

Published: April 03Project Number: C10041

Get ReportAuthor: Ian Fletcher, Dick Sanders | QCC Resources

Coal moisture, and particularly in situ moisture (Mis), is a parameter which is often examined inadequately during exploration programs, and the resulting limited knowledge can easily impact negatively producing inaccurate definition of reserves, incorrect estimations of product moisture levels, and poor tonnage reconciliations. Mis is very difficult to determine. This project set out to determine the means to estimate Mis.

Coal samples were collected from 17 different sites, with a reflectance range of 0.40-2.49%. Four types of samples were collected, (i) large lumps (generally 5-10 kg) from freshly exposed underground and above ground seams, (ii) lumps from 200 mm deep holes in seams cut with a 200 mm diameter concrete drill, (iii) borecore samples (up to 100 mm core) and (iv) washed coal samples. All samples were packed and sealed as quickly as possible after collection to avoid any moisture loss. Lumps were selected from the raw samples and treated as follows: saturation in water under reduced pressure; determination of the relative density, and moisture, of the saturated lumps; and determination of a range of coal quality parameters. A survey of the coal industry was carried out, seeking data on the various moisture parameters and other general quality characteristics.

The moisture of the as received lump coal was taken as an approximation of Mis. Lump samples increased in moisture during saturation by an average 0.4%. It is believed that, during the saturation process, moisture enters tiny fissures and cracks in the coal that were generated during the relief of seam stresses prior to the exposure of the working face.

Offsets between moisture parameters from the sampling program were generally supported by those from the survey, although the survey offsets were indicative only. The difference between in situ moisture and moisture holding capacity (MHC) type parameters was found to be significant contrary to international research.

The Preston & Sanders equation for the calculation of relative density (RD) from one moisture basis to another has been tested, and the results support the validity of the equation.

Results from moisture holding capacity and equilibrium moisture have been compared, and no significant differences were observed for values below 10%. There appears to be little difference in reliability between MHC (for higher rank coal) and EM.

A procedure for the estimation of the in situ moisture is described which involves the use of equations to calculate values for Mis using a range of parameters. The calculated results are then considered in the light of other knowledge of the deposit, such as geological data, other analysis data, data from other local mines, etc, to determine final estimated values. RDis can then be calculated using the Preston & Sanders equation.

Multi-variable regression was also used to develop an equation for washed product moisture levels. The parameter determined is Mcent,best which is a measure of the lowest product moisture likely to be obtained in a properly maintained and operated coal dewatering plant. Likely product moistures will range upward from this value.



Health and safety, productivity and environment initiatives.


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


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