Underground » Detection and Prevention of Fires and Explosions
AiroDust is the commercial name given to the foam treatment process of coal mine approved stone dust. The process involves mixing the AiroDust additive (ADA) with mine water to create stone dust slurry. The slurry is then processed to create a designed foam to a specific density that is sprayed onto the mine wall, roof and floor.
The ADA reduces stone dust caking by inhibiting electrostatic attraction and calcium carbonate recrystallisation. The additive also contains surfactants that are an enabling part of the foam generation. The foam dries as moisture is evaporated into the mine atmosphere or absorbed into the substrate. The result is a dry aerated stone dust coating that when exposed to a shock wave disperses to form a dry dust cloud.
The patented process consists of five main steps:
1. Combining mine water and stone dust to create wet stone dust slurry;
2. ADA is introduced into the slurry stream as it is pumped;
3. Slurry and additive mixture is combined with air to generate foam;
4. The foam is sprayed onto the mine roadway surface;
5. The foam dries as the moisture evaporates into the mine ventilation and into the underlying substrate.
Independent researchers and internationally recognised coal dust explosion experts have reported that AiroDust, manufactured and applied within the manufacturer's guidelines, is as effective as dry stone dust in its ability to suppress both low and strong energy coal dust explosions.
Research established the minimum and maximum tolerances for the critical elements of the AiroDust treatment process. These tolerances form the AiroDust manufacturer's guideline parameters.
Consideration of potential risks of introducing the AiroDust process into underground coal mines were assessed through an industry design and effectiveness risk assessment and through onsite operational risk assessments.
These risk assessments considered the research results, the preparation of AiroDust in accordance with the manufacturers guidelines, the application in an underground coal mine and the risk associated with ongoing compliance with the recommended guidelines.
They determined that the research and testing results have demonstrated the process to be at an acceptable level of risk to introduce into underground mines. The operational risk assessments have determined that operating the AiroDust process and maintaining within the recommended guidelines is also at an acceptable level of risk. It was the view of the risk assessment teams that introducing the AiroDust process could commence in accordance with a controlled introduction plan. This plan was designed to minimise the number of initial sites whilst additional operational data could be collected. The type of data includes measuring drying times in real underground conditions and total incombustible content comparisons with dry stone dust.
This data will add to the knowledge of the product and enable additional sites to adopt the process without the need for controlled introductions.
A package of information relating to this ACARP project and other relevant information has been collated into a single source. This information pack is known as the Senior Site Executive (SSE) Pack. The purpose of this information pack is to create a single source of reference for owners and managers interested in the introduction of AiroDust, an alternate means for applying stone dust in underground coal mines.
AiroDust is presented in this information pack as an alternate process of applying coal mine approved stone dust. This information is designed to provide owners and managers with the information required to assess the level of risk with the introduction of AiroDust. There are specific documents that are critical in the process of assessing the level of risk for the product's introduction. A summary table of these are included.
The most up to date data relating to the AiroDust product information, test results and support can be found by contacting Applied / ITW Polymers and Fluids via their web site Itwpf.com.au