Revision of AS4156.6 Dustiness Test

The current Australian Standard AS4156.6 "Coal Preparation - Part 6: Determination of dust/moisture relationship for coal" describes a unique method to determine the minimum moisture content required for the dust extinction of coal, termed the Dust Extinction Moisture (DEM). This method has become common with testing outcomes used in practice to control and manage coal dust emissions, from pit to port. Despite its significance, the method has found itself under scrutiny, particularly regarding the potential to underestimate the amount of moisture required for dust extinction, which could lead to unpredicted operational, environmental and health issues.

The initial objectives were to:

· Review of the existing dust measurement methods and standards;

· Development of a reliable reference method to produce airborne dust from a bulk material sample;

· Application of an up-to-date dust measurement system;

· Introduction of a dust classification defining airborne dust in terms of health-related fractions, i.e. PM10, PM2.5 and PM1;

· Addition of a procedure to convert test sample DEM to full product sized DEM;

· Introduction of Optimum Moisture Level (OML) to achieve moisture level above DEM during site residence time at port terminal or mine site;

· Preparation of a document for submission to the Australian Standard Committee.

Due to unforeseen circumstances the results of the initial investigation shown in this report are open to interpretation and may require further clarification.  It is important to note that the comments in this report regarding the initial investigation have been formed based only on the results observed and presented. The procedure, methodology and additional background information regarding most of these tests and results presented have not been taken into consideration. In some cases the test conditions were also not recorded or known. As such, the initial investigation has been used as a preliminary study to further advance the progress of the project.