SPONTANEOUS COMBUSTION MANAGEMENT
CLIENT
Open-Cut Coal Mine located in the Bowen Basin, Queensland
ISSUES
The mine had been dealing with major spontaneous combustion (Spon Com) and dust management issues and was looking for a targeted approach to mitigate and manage hot areas. With significant loss of non-blasted material in 2019, which directly affected production targets, initiatives were required to reduce lost blasted ground and to reduce the effect of Spon Com on site.
OUR APPROACH
Xenco representatives, working with site leaders, went through a process to assess plans to reduce Spon Com on site. On an initial visit, seventeen (17) recommendations were highlighted with five (5) high value initiatives identified in conjunction with client representatives to move to trial stage. A Xenco Project Manager led the onsite implementation of the initiatives, which included:
- Developing and managing the five trial projects
- Conducting project procurement
- Designing in-pit water cooling tools
- Creating and coordinating Risk Assessments, Job Safety Analysis and Work Instructions
- Providing new procedure training for employees
- Change Management
PROJECTS 1 AND 2 | MEASURING TEMPERATURE
Measuring temperature, in particular underground temperature spikes due to Spon Com, is designed to facilitate more effective mine planning. Knowing the temperature before drilling and blasting begins allows the development of a site temperature model and the ability to work around the areas identified with higher temperatures in the drill pattern. Furthermore, enabling more accurate drilling and improving fragmentation of the blasted material allows the dig units, primarily the dragline, to be more productive, with higher BCM per hour rates.
PROJECT 3, 4 AND 5 | USING PIT WATER TO COOL HEATED GROUNDS AND HOLES
Two projects were carried out to introduce the pre-soaking of spoil ahead of excavation and dragline operations. This involved pumping water from the pit and running it through a series of water lines to the relevant locations to provide the custom water sprinkler to soak spoil pile.
The site had also suffered from significant losses due to hot areas where they were not able to load and blast drilled holes on the exposed benches. To address this issue, Xenco introduced the use of a custom water manifold to flood the hot holes (+100°C) with water from the pit to reduce their temperature. Once the temperature in these holes is reduced, operations can load and blast, thus leading to a better fragmentation in these areas.
OUR RESULT
Through the leadership, expertise and engagement of the Xenco team, the five projects were delivered within budget and schedule. Recording of temperature and the development of a site temperature model now allows the mine planning team to better work around hot areas in the drill pattern. Use of the water manifold to reduce hot holes temperatures, has seen site achieve a blasting completion of 95% in August 2020, which represents an increase of 30% compared to last year.
More data on the effect of these trials will be made available at the end of 2020.
Xenco provided specialised support to reduce recurring spontaneous combustion and dust issues at this major coal mining operation.