Review of the current Australian Standards for coal flotation

Coal flotation tests are routinely used to evaluate the washability (through flotation) of coal and to optimise flotation plants. The usefulness of flotation tests for decision-making depends on the quality of the data. This study showed variations in the practices of different laboratories. Whilst they may not affect the final outcomes, it is important to for industry to understand what constitutes best practice and to understand those variations in practice.

Consultation with the industry during this project determined that the standard is often adapted within the guideline. However, there are some ambiguous points in the standard procedures, which need clarification which this project aimed to do. In addition, it became evident that there was a need to share best practice. The development of a single point of reference can assist practitioners and trainers in obtaining accurate and reliable results from coal flotation tests. All these points will be addressed with the creation of a handbook to assist operators to conduct flotation tests.

It was recommended that the handbook should be presented to Standards Australia to complement the standard procedures. The resulting handbook (and this report) will assist practitioners to conduct

better experiments, which is vital in decision-making.

Review of the current Australian Standards for coal flotation (phase 1)

This study compares the reports produced by the various laboratories with the requirements laid out by the Australian standards.

A thermal coal and a metallurgical coal were sent to 8 laboratories, which were requested to perform a basic flotation test and a sequential flotation procedure test (standard tree test). It was found that many elements were missing in most cases, probably from the fact that some of the requirements of the standard, such as size analysis, are offered as other services. The results from the basic test and the sequential procedure were analysed. The former generally agreed with one another whilst the latter presented more variations. A quantitative analysis of the variation in the yield-ash curves produced by the sequential procedure was conducted using Dynamic Time Warping (DTW). This approach can be used to numerically compare yield-ash curves and perform statistical comparisons.

THE TWO FINAL REPORTS ARE AVAILABLE AS A SET.