FRACTURE-BEHAVIOR OF 3 AUSTRALIAN IRON-ORES

During mining, crushing and transport iron ore is subjected to forces that cause the material to fracture into fine particles, a process tha t is referred to as degradation. The toughness and fracture mechanism of three Western Australian iron ores, Yandi, Koolan and Mt Whaleback, were studied with a view to understanding their degradation behaviour . The microstructures of the three ores are significantly different an d they were therefore expected to show differing fracture behaviour. T he bulk fracture toughness of the specimens was determined by the thre e-point single-edge notch beam test and the results were interpreted u sing Weibull statistical analysis. Indentation fracture mechanics was also used to measure the fracture toughness of the different mineral f orms in the ores and to provide an understanding the response of these minerals to contact fracture. By correlating the results of the mecha nical tests with microscopic observations of fracture patterns it has been possible to gain an insight into the complex fracture mechanisms that occur during degradation.