Open Cut » Environment
This project successfully developed and demonstrated a complete system to monitor and predict in real time the ground level concentrations of blast fume in and around open cut coal mines. This report describes the system and the outcomes of five trials of the system during blasts at the Meandu mine.
The system consists of 20 fume stations, two weather stations, two gateways with 3G network connectivity and webcams, remote server software, and an iPad end user application.
The compact fume stations were able to be rapidly deployed at key locations around the blast site. They utilise low cost commercial off-the-shelf NO2, NO and CO gas sensors, which proved to be reliable and stable. The sensors in the fume stations were covered between the trials and showed negligible changes in sensitivity over approximately 12 months; two sensors that were continuously exposed to office air during this period showed a 10% decrease in sensitivity.
CSIRO wireless sensor network technology was customized with a GPS module for the fume monitoring system. It automatically transmits the data to a central server using 3G connectivity. This central data management server provided for archival and retrieval of data and for execution of plume forecasting algorithms.
Nowcasting of plume behaviour was implemented based on established plume modelling techniques
that were customised to utilize real time measurements from the fume stations.
An iPad application was developed to present an end user at the mine with a real time map based visualization of the complete fume situation, including short term forecasts of plume movement and dispersion.
The system operated reliability and with no loss of data.
In contrast to existing practice, this new fume system gathers fume concentrations from a multitude of locations (both within and outside of the blast exclusion zone). The central data management server makes it straightforward to access fume data from all locations in near real time or retrospectively without any manual handling/processing of data. This increased spatial density of fume monitoring and real time access permits an improved understanding of plume extent, intensity, movement and dispersion.
Additional enhancements that could be considered for future inclusion in the system include:
· Incorporation of the factors that contribute to fume generation into the plume modelling and prediction, such as the presence of water, level of confinement, blast design, depth of holes, suitability of blast product, powder factor etc;
· Inclusion of additional gas sensors to monitor other types of fumes encountered in open cut operations. For example, hydrogen sulphide (H2S) and sulphur dioxide (SO2) produced through spontaneous combustion; and
· Inclusion of additional sensor types on each monitoring station for measuring other parameters of interest, such as dust and noise levels, ground vibration, air blast, etc.