MINE VENTILATION
Howden is installing a level 4 Ventsim CONTROL VoD solution at the South Deep mine in South Africa
The level 4 VoD solution employed by South Deep will allow ventilation devices to react based on feedback from environmental sensors underground , according to Howden . It will furthermore adjust mine airflow in real time based on vehicle and personnel position . The
Ventsim CONTROL solution also offers a 3D modelling capability within the software , which helps users to better predict and control air flows based on what is evidenced in the simulation .
Eric Vemer , President of the Africa region at Howden , said : “ The installation of Ventsim CONTROL will improve the operability and flexibility of the mine ’ s ventilation system to ensure a safe , healthy and efficient ventilation solution . Ventsim CONTROL will further reduce energy consumption and associated tonnes of carbon emissions . As the system allows the mine to optimise its ventilation based on fully remote vehicle and personnel monitoring , it directly contributes to achieving emissions reduction targets – something of which the Howden team is very proud .”
LTE-backed VoD at Olympias
Eldorado Gold recently confirmed it is testing Newtrax ’ s environmental monitoring platform and ventilation on demand ( VoD ) solution at the Olympias mine in Greece .
Mine ventilation represents the single largest electrical load at the Olympias mine and , in response to the EU energy crisis and Eldorado ’ s own Energy and Carbon Management System , the company has been aggressively advancing VoD implementation at the Greek operation .
The benefits associated with VoD include : n Targeted air circulation and improved air quality as the working environment is upgraded as fresh air is distributed through the mine in a manner that ensures workers ’ health and safety ; n Right-sizing fans to provide the required volumetric flow rates ( from a static to a dynamic and intelligent air supply leading to a reduction of the total required airflow within a mine ); n Improving energy efficiency and power consumption – by reducing the total airflow , energy can be saved in disproportionately high amounts due to the cubic relationship between volume flow and fan power ; and n Enabling the production and development activities at the lower levels of the mine . To obtain the immediate benefits of VoD , the Olympias mine operations team implemented a manual solution during 2022 , where the team adjusts ventilation fan operations each day based on the daily mine plan . As part of this , variable speed drives were applied to many of the fans to allow air flow adjustments to meet operational needs with minimum electricity consumption . This process is being carried out via the control room on surface , with a SCADA system used to disconnect fans that are not planned to be used during the day .
This transition saw ventilation fan consumption decrease from about 620 kWh / mth of electricity consumption per kW of installed fan capacity to about 377 kWh / mth of electricity consumption per kW of fan capacity , representing a 40 % decrease in energy consumption , according to Simon Hille , SVP , Technical Services and Operations . At the end of 2022 , the mine had 3.1 MW of installed ventilation capacity .
“ This 40 % reduction represents about 9,051 MWh / y of electricity savings and about 3,800 t / y of GHG emission reductions ( utilising the updated emissions factor of 0.42 t CO 2e / MWh ),” he told IM .
While manual VoD has been very effective , automated VoD will further decrease energy consumption and eliminate the many worker hours required to implement VoD on a daily basis , according to Hille .
This is where the company brought in
Newtrax , part of Sandvik Mining and Rock Solutions , to implement an automated VoD system .
The Olympias mine will be the first Newtrax installation utilising LTE as the communications medium versus low frequency radio ( leaky feeder ) utilised previously , according to Eldorado . LTE was installed in August 2022 .
The automated platform will also leverage data from the existing fleet management system and RFID-based employee location tags provided by Newtrax . Ventilation will then be provided by surface fans with higher ventilation capacities .
Olympias already uses Accutron Technology to monitor air flow velocity and Trolex technology to monitor mine air quality , according to Hille .
In addition to the VoD benefits , the Newtrax technology will improve mine safety ( mine evacuation and rescue ) as well as improve productivity by allowing mine supervision to have a better understanding of resource locations for improved decision making , the company says .
“ Technology and connectivity are the key parameters for VoD to operate effectively ,” Hille said . “ Automated employee and equipment geolocation is necessary as it helps adjust ventilation delivery to different areas by effectively shutting down entire areas and thus reducing the overall ventilation demands . This requires smooth connectivity with the LTE across the mine site .”
Last month , Newtrax installed five Bluetooth low energy ( BLE ) devices on select mobile machinery to test system connectivity . Once troubleshooting is complete and communication is established between the underground fans and Newtrax BLE devices , full-sized implementation will be considered with equipment procurement , installation and commissioning to be done by end of Q1 ( March quarter ) 2024 .
On top of this , Eldorado Gold is evaluating non-diesel powered equipment for all new equipment purchases and , in some cases , as an alternative to equipment rebuilds .
“ The mine ventilation benefits of equipment electrification are included in the evaluation of that equipment ,” Hille added .
A refreshed Vigilante AQS
Four years after bringing the Zephyr AQS™ to the attention of the crowds at CIM in Quebec , Canada , Maestro Digital Mine was back at the event this year to present an updated version of its flagship digital industrial internet of things solution , Vigilante AQS .
At the show in late April , the company held a relaunch event for the second-generation solution , marking Vigilante AQS ’ 10th anniversary .
14 International Mining | JULY 2023