Open Cut » Environment
The objectives of this project were to undertake scientifically rigorous dust studies around coal ports to provide quantitative particle size and abundance information for coal and other particulates in these samples which would also be accepted by the general community. Coal dust is an issue of community concern, particularly associated with the handling of coal on railways and ports in urban environments, so it is important that analysis results can be closely scrutinised and the findings questioned by scientists, residents and community groups. This project used CSIRO's Coal Grain Analysis (CGA) technique which is based on petrographic principles applied to photomicrographs and the associated reflectance fingerprints on individual dust particles which are greater than approximately 1 micron in size.
In reflected light images, many of the different particulates present in urban dust samples display differences in brightness, colour and texture. These differences can be used by an expert petrographer to identify these particles and a project objective was to use these attributes and supervised learning techniques to develop optical dust markers to automate the identification of dust particulates in these images.
Three case studies were undertaken, one at a peak site located onsite at the Hay Point Coal Terminal near Mackay, the second at a community site in West Mackay and the third at two sites in Newcastle (NSW). The length measurement of each particle was used to size the particles for the two case studies conducted at Mackay. For the Newcastle study, the effective diameter measurements were used to place the particles in the specific size classes and the area and volume information were used to determine the amount of particles present in the samples. Other aerosol tests report results on a volume or mass basis and thus reporting CGA results on a volume basis allows for a better comparison with the results obtained by other methods.
Image Viewing Software has been developed which allows results for dust analyses to be uploaded to the internet and viewed by interested parties. This software provides the size and composition information for each individual particle and the amount and composition of the material in the nuisance and respirable size fractions. Links to the dust results uploaded into the image viewer dynamically demonstrate how the image viewer is able to be used to obtain detail for every particle in the sample and summary information for the different particulates in each different size fractions.
The case studies have demonstrated that CGA can accurately determine the amount of coal which is present in urban dust samples and can then report the information in a way which is able to be accepted by community groups, via the use of the Image Viewing Software.