ACARP, Queensland Rail (QR) and CSIRO are completing the second stage of a study into sticky coal with completion of the project set for March 2004.

The first stage of the project conducted by QR and researchers from CSIRO divisions of Exploration and Mining and Energy Technology looked at design features of rail wagons that would inhibit coal flow, attributes of coals that would cause problems and cost effective solutions to minimise the problem. This initial project was completed at the end of last year.

CSIRO coal technologist Graham O’Brien said the project found the loading and unloading of the wagons are the two steps in the transport chain where most improvements can be made.

“For the mines that have issues with sticky coal a modification of loading method to lessen loading force should improve the unloading characteristics and hence reduce unloading time,” O’Brien said.

“The unloading of trains would be improved if the jackhammering process could be improved. Higher frequency jackhammers showed significant operational benefits and their use should be trialed at the ports, subject to conformation that there is no detrimental effect on the wagon structure. Improved jackhammering will result in reduced train turnaround time, reduced costs and more effective scheduling.”

“The loading of the coal was found to be a critical step that affected the degree to which an already sticky coal will hangup in the wagon. Modifications to the loading methods at the mine can lessen the loading force and thus improve the unloading performance of the coal.

These initial findings have been used in an extension project that looks at developing methods for reducing loading force without significantly increasing loading times. The project will firstly benchmark the forces due to the current loading method and conduct laboratory trials to test methods for reducing loading forces and hence the consolidation in rail wagons. It will then modify the loading method used at a mine and assess the improvement in unloading.

Fieldwork is currently being undertaken at the Boonal load out which uses an impact loader to load Jellinbah and Yarrabee coal products for transport to RG Tanna Coal port in Gladstone. Accelerometers mounted in a coal wagon allow the distribution of loading forces generated with the current loading method to be determined. This information will be combined with jackhammering monitoring data that the Gladstone coal port is collecting to benchmark the current operation.

“Laboratory testing will identify for both impact and clam shell loaders the most effective method for reducing consolidation caused by the loading of wagons that has least impact on loading rate,” O’Brien said.

“Each mine that has a problem with sticky coal may require a different method to reduce loading force without significantly impacting on train loading times. Advice will be provided to the mines that wish to alter their loading method to reduce consolidation.”