Coal Preparation

Image Analysis Measurement of Screen Aperture and Open Area

Coal Preparation » General

Published: November 03Project Number: C11006

Get ReportAuthor: Michael O'Brien, Douglas Nemeth, Terry Wex, Stephen Sullivan | CSIRO Energy Technology, A&B Mylec

The project's objective is to develop a portable prototype measurement system using a digital camera and a laptop computer to measure screen aperture and open area. The measurement of the screen aperture will include the number of aperture measurements made, the mean, histogram and the standard deviation of those measurements. The open area measurement will be inclusive of pegging and the system will have the ability to calculate total screen open area from the input of screen parameters.

The device has been successfully tested at three Bowen Basin plants on over 9 plant screens using commonly used screen panels, including wedge wire, by both researchers and consultants (Table 3 section 6).

The system outputs the mean aperture, the standard deviation of the aperture readings and a histogram of the measurements for each panel and logs the aperture, standard deviation, open area of a clean deck and percent pegging of the analysed region of interest (ROI), however this can be adjusted to give data on each individual measurement within the ROI as required.

Percent pegging has been qualitatively estimated in the past by some consultants and researchers when considering the relationship between efficiency and effective open area. This system gives quantitative data that has not previously been available. Similarly the estimate of standard deviation and the concept of a measurement histogram have not previously been quantitatively available to researchers, consultants or plant personnel.

Aperture standard deviation is an important parameter when examining the data from the screen decks. In effect this figure will give an indication of the "condition" of the panel, screen deck or screen section such as the screen drain or rinse. High standard deviations are indicative of irregular screen apertures, which may result from unequal panel wear.

The histogram of the aperture measurements is a convenient visual method to describe the variation in measurements. The histogram can be produced for individual panels, for the entire screen or for screen sections and can be used to visually observe the panel wear.

This system provides a method to quantitatively measure screen aperture, effective open area, percent pegging and panel wear (standard deviation and histogram) for plant maintenance purposes and screen efficiency calculations. Regular use of the system may enable operators to predict a panel or screen's critical wear point (where wear has caused sufficient oversize material to report the underflow leading to measurable screen inefficiencies that affect product yield).

The new technique for screen deck measurement, through the analysis of digital images of individual screen panels, promises to provide a robust method for the measure of screen panel aperture and actual screen panel open area. The technique was able to achieve realistic results over a range of scenarios including various screen panel designs, panel conditions and screening applications. The image analysis software provides a mechanism for the measurement of screen panel aperture that is less dependent on the operator than current visual measurement techniques, although the selection of the segment of the deck to be analysed remains at the discretion of the operator. Commercialisation of the device would be via a local equipment or screen manufacturer with international links. The industry would use this device as a means to plot screen wear with time in order to determine the critical wear point where the efficiency of the screen has decreased to the point where the cost of the lost product Vs screen replacement is high. These measurements would also lead to an improved ability to predict residual panel service life, lower material usage and reduce the frequency of unplanned shutdowns.


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