The following thesis details the analysis of results obtained through column and adiabatic testing of Great Northern Seam coal samples from Centennial Coal.s Mandalong Colliery, Newcastle. The coal seam at Mandalong Colliery forms part of both the Great Northern Seam as well as the West Wallarah Seam, but is commonly referred to as the Great Northern Seam.
In March 2004 a batch of coal was received by The University of Queensland from Mandalong Colliery to perform a series of self-heating tests. It was agreed that fresh coal would be supplied for the test work. The coal originated from a gateroad entry which had been developed in 2004.
Adiabatic testing has been conducted in the past using coals from many Australian operations, in order to determine the self-heating rate (R70) value specifically for each mine. The R70 is obtained through the standardised adiabatic testing procedure, and allows for any one coal to be compared to other coals tested.
R70 values for the Mandalong samples ranged from 1.47 to 3.11°C/h. The lowest value corresponds to an ash content of 41.4% dry basis and the higher value corresponds to an ash content of 14.4% dry basis (see Section 3). It has become apparent that moisture content may be a significant moderating factor in the self-heating rate of Mandalong coal. This assumption is due to the accelerated self-heating rate of test Mandalong 5 (drier, gas-drained sample).
Larger scale tests were conducted through the use of the UQ 2-metre column, to analyse the hot spot development for this coal (see Section 4).
Throughout each column test, gasbag samples were taken at varied temperature intervals. These gasbags were then sent to SIMTARS for analysis with a gas chromatograph. Instant gas evolution readings, however, were taken daily at UQ with a Minigas or Draeger Multiwarn.