Wallerawang colliery rehabilitation: the coal tailings briquetting process

The Wallerawang colliery, located 15 km north of Lithgow in the western coalfields of NSW, utilised a coal fines briquetting (agglomeration) process to aid in site rehabilitation. The project was used to establish a void of approximately 200 000 m 3 for the burial of sulfidic (acid producing) coarse washery reject by turning a waste material into power station fuel. The briquetting process utilised a double roll press to produce approximately 70 000 tonnes per annum of 50 mm diameter briquettes from drained coal tailings (fine coal washery reject) stored within the site tailings dam. To the best of our knowledge, a briquetting project for the reprocessing of coal tailings as a fuel for conventional power stations had not previously been successfully operated. With extensive energy resources stored within coal tailings dams worldwide and the difficulties sometimes encountered with tailings dam rehabilitation, the potential for the development and future use of this process is considered large. As such, the project represents an innovative example of the implementation of the principles of Cleaner Production and Ecologically Sustainable Development in the coal mining industry of New South Wales, Australia.