Abstract: By teaming up with Newtrax, Newcrest’s Toguraci Mine was able to implement a dewatering solution that made their mine safer and more productive. It has proven to lower the risk of flooding while at the same time reducing downtime of standard operations when flooding did occur. Lastly, by moving past hardwire interlocking connections and replacing them with wireless network controls, Toguraci has made their mine into a safer work environment.
The Toguraci Mine in Gosowong, Indonesia has been in operation since 1999. It is operated by the Indonesian mining company PT Nusa Halmahera Minerals (PTNHM). 75% of the project is owned by Newcrest, an Australian based company and one of the world’s largest gold producers.
Gosowong is a small, remote island located off the coast of Indonesia. Because of its location, and the extreme depth of the mine, it is affected by intense and invasive flooding of high-temperature water. Ground water that makes its way into underground workings is up to 80 degrees Celsius further compounding surface air temperature and humidity problems as well as nullifying any cooling initiatives. This, in effect, slowed down production and endangered the lives of mine workers. Furthermore, cooling of the air that was brought underground to 16 degrees Celsius had little effect on the wet-bulb temperature of the face.
Over time, Toguraci realized that operating under their current flooding conditions was no longer realistic and began to seek out advice and guidance for a more permanent solution that would be both cost-effective and safer for their employees. Toguraci reached out to Newtrax in 2016 to form a partnership.
Together, they were able to implement an IoT based telemetry system designed especially for Toguraci. The implementation of this system has made their mine much safer while also maximizing productivity.
The Toguraci mine operation is a small mine (1.5ktpd) that needs to pump 300 Litres per second for dewatering purposes. Flooding of specific areas would shut down the production of the mine from several hours to several days and occurred frequently over the course of many months.
There were many causes of flooding in the mine:
- Changes in the earth’s water table levels that occur due to heavy rains or other natural events
- Internal issues with the mines dewatering pump system and stations
- Inability to take timely action when changes in water levels occur due to mining activities
Besides flooding, Toguraci is also affected by unusually high water temperatures ranging from 70-80 degrees Celsius. Water at this temperature causes 3rd-degree burns if it comes into contact with human skin. The high water temperature also causes the earth and the mud that surrounds the mine to become extremely hot. Besides the threat of burns to personnel, these high temperatures change the climate of the mine, making the mine extremely hot and humid to the point of it being unsafe for workers to enter.
Newtrax Global Support Manager, Martina Barnett, explained how Toguraci used to manage their dewatering pump system and how that system was defective.
“They had a problem with their pump interlock, because the way that they would implement their dewatering was in multi-stages. If the pumps on one level stop working, the pumps that feed into that pump also need to stop working. Otherwise the [mine] floods.”
She went on to break down how the borehole pump system is configured at Toguraci, explaining that, there are three levels of pumps that were being controlled manually and by hardwire connections.
The lowest level borehole pumps were responsible for the intake of water coming directly from the earth’s water table. When it would fill to capacity, overflow water would then be distributed to the midlevel holding tanks (or “fish tanks”). When the Fish tanks reach capacity, they would pump water to the top level holding tanks. Communication between the different levels of holding tanks was facilitated through a hardwire system, enabling the lower holding tank to know when the fish tanks above were full.
Unfortunately, the connection was often lost and the midlevel tanks would flood, creating substantial damage and setbacks before workers were able to rectify the situation. When these issues would arise, an employee would then be sent, sometimes by boat, to manually turn off the tanks and manage the pumps correctly to effectively dewater the mine. Having an employee descend in these hazardous conditions obviously poses many risks to the individual and subjects them to an unsuitable environment.
Toguraci had two issues that needed to be solved in order to advance their mine and make it safer. They needed to:
- Enable remote control of the pumps and holding tanks. This eliminated the need to send down personnel to manage the pumps manually.
- Create a system that would alert relevant personnel in the times of crisis. This mitigated the damage and gave personnel more control, enabling them to get the mine back to production sooner.
With these goals in mind, Newtrax knew they needed to create a new product that would be centered around their pre-existing MineHop network. This would allow the mine to run bore pumps on a wireless network that could be accessed from anywhere in the world.
Through the years, Newtrax has gathered extensive knowledge and insight on telemetry technology and were able to use this when engineering the bore pump telemetry for Toguraci.
This project was considered nonrecurring engineering (NRE), an independent product and solution specifically crafted and designed for Toguraci with the intention of making this particular mine safer and more productive in general.
Newtrax started by integrating the MineHop system into the current bore pump system present at Toguraci. This application was put in place to connect the equipment underground to the main network above ground. The MineHop network is able to connect individual pieces of telemetry technology and share their status and data through the networks internet connection. This is done through the use of nodes placed in and around the holding tanks that take in real-time data and transmit that information to the server on the surface.
Newtrax also incorporated their existing Vibrating Wire RTUs connected to piezometers, sensors which measure the water pressure in a borehole, thereby allowing the system to calculate the level of the earth’s water table. By adding these devices, personnel could see the current level of the water below ground and prepare the pumps presumptively in the event of a water pressure increase.
Newtrax then collaborated with Indus-Comm to create I/O controllers that are able to interface with the MineHop system. These I/O controllers ensure easy and remote access to the pumps and monitor the status of the holding tanks. Combining the date from the I/O Controllers and the Vibrating Wire piezometer RTUs allows personnel at Toguraci to remotely close and open connections on different pieces of equipment. Indus-Comm created two separate I/O Controllers for Toguraci.
Digital Monitor/Controller- This allows for monitoring and controlling of the tanks allowing personnel to see whether they are on or off, and if there is an issue with the equipment.
- Analog Monitor- Allows for monitoring of flow meters and other number-based measurements.
It was important for Newtrax to enable Toguraci with wireless network access capabilities. This is why they chose to use their MineHop network to connect all the systems. Having quick, real-time information, is crucial for allowing Toguraci to recognize and fix flooding issues on the spot.
Being connected through the wireless network enabled anyone with access to the system to easily log in to the dashboard and immediately see the statuses of each pump and their location. The dashboard is animated with widgets that help personnel visualize where the problem is and how they can resolve the problem in the most timely fashion.
This is also an important key point for training new employees. Having a system that is simplistic and user-friendly lends itself to shorter training periods and less room to make mistakes.
Another advantage of having an internet based system is it is easily accessible from anywhere in the world. This means that when an issue arises, personnel can quickly log in and assess how to fix the issue. They can then remotely shut off or turn on pumps to new holding tanks. Being able to do this in a timely fashion saves the mine from unnecessary damages and clean up. Having the bore pump system remotely operated also makes the mine safer by eliminating the need to send down personnel to manually manage the pumps in dangerous flooding conditions.
The implementation of the system was completed within a week, and the actual installation of the key equipment took approximately two man days.
The project’s aim was to reduce the insufficient performance of the existing mine pumping stations operating together as a system. Specifically, the system was forecasted to reduce the number of flooding events from the tripping of upstream / top level (primary pumps) from over 10 hours per month to less than 2 hours per month (5 x decrease in duration) as well as generate a 2x reduction in the number of flooding events.
Since the system was implemented in April of 2016 it has greatly reduced the occurrences and effects of flooding in the mine.
By incorporating this system, it has allowed Toguraci to have a proactive approach when dealing with flooding issues. Whereas before the Newtrax system was implemented, Toguraci was only able to have a reactive response. This was achieved by enabling personnel to see real-time data that they are able to manage online.
In the event of a flood, it is easy for personnel to act fast and spring into action to avoid unnecessary damages. Having quick and accurate access to information has limited the amount of downtime and has enabled the mine to continue production while mitigating flooding issues.
Often when a company decides to integrate a new operating system it requires intense training or the hiring of an outside contractor to come in and handle the operation of the system. This is because many companies’ solutions run from software which is complicated and hard to interpret.
It was important for Toguraci and for Newtrax that the system was easy to use so the local workforce was able to operate the system themselves. As explained by Patrice Corneau, Product Owner at Newtrax Technologies, the goal was to create a system that would have
“easy configuration, easy modification for the local electrician[s]”.
Giving the local workforce the ability to manage the system themselves ultimately saves the mine a lot of money while also enabling faster response time and better outcome.