Work on what will be the world’s first fully automated underground gold mine, the Syama Underground Mine of Resolute Mining in Mali, is progressing well. A sublevel cave, the mine achieved commercial rates of ore production in June this year and the commissioning of the Syama Underground Automation System is now well underway.
Operators in the newly completed surface control room are able to control underground production units over shift-change, blasting and re-entry periods, when there are no personnel in the underground mine. According to Resolute, which is listed on the ASX and LSE, this represents the initial delivery of one of the main benefits of automation – the ability to maintain production over periods when operations would normally cease in a typical manual mine.
The new Syama Automation Control Room.
The fibre optic backbone and mine-wide wireless network is now complete from the portal down to the 1055 haulage level and is connected to the surface control room. This network enables the operation of the automated haulage loop, automated rehandle level, mine digitisation and production automation, all of which allow operators to monitor and control mine production in real time.
A major technical characteristic of the world’s first fully automated haulage loop is the ability for Syama’s haul trucks to rapidly transition from laser-based underground navigation to surface-based differential global positioning system (GPS) navigation. Recent trials at Syama have demonstrated Resolute’s haul trucks are able to acquire the feed from the two surface GPS base stations and seamlessly lock onto satellite guidance to complete the transition to GPS navigation without any delay or speed reductions.
The next phase of automation work will see the commissioning of the 1055 haulage level with automated rehandle loaders and haulage trucks working together to load from an ore pass and truck directly to the surface ROM pad.
With the fans, pump stations, control room and communications network complete, the automation project is being progressively handed over to the operations team which is now at normal operational manning levels.
The mining equipment and automation systems for the Syama Underground Mine are being supplied by Sandvik Mining and Rock Technology, which in June last year reported that it had signed a strategic framework agreement with Resolute. In its announcement on the agreement, it said it was delivering the proven AutoMine® and OptiMine® systems for analysis, process optimisation and automation, including a full fleet of Sandvik TH663 trucks and Sandvik LH514E electrical loaders.
Commenting at the time, John Welborn, MD and CEO of Resolute, said: “Sandvik is one of the world’s mining industry leaders and innovators and the only equipment provider that can offer the full suite of proven autonomous equipment and digital solutions we require.”
At full capacity, the Syama Underground Mine will produce approximately 46 000 tonnes of ore per week, or 2,4 million tonnes per year. All key aspects of the mine are now operational with daily ore haulage rates regularly above 5 000 tonnes per day and more than 38 500 tonnes of ore having been mined and hauled in the last week of June. This level of mined and hauled tonnage is expected to be sustainable on a quarterly basis.
In its latest quarterly report (to 30 June 2019), Resolute says that substantial progress was made in development rates, drill and blast performance and sublevel cave drawpoint availability. This resulted in total blasted ore tonnage mined increasing to a total of 622 969 tonnes. Ore hauled to the run-of-mine (ROM) pad during the quarter totalled 329 000 tonnes. This represents more than double the hauled tonnes achieved in the March 2019 quarter. The production improvement has been achieved by the successful development of additional production slots which has allowed the number of active stoping areas (drawpoints) to be increased from six to 12 over the course of the June quarter.
As current stoping activity is occurring on the first production levels of the cave, a significant quantity of the ore blasted in the stopes is retained in-situ in order to create an ore blanket against future hanging wall dilution. These ore tonnes will be recovered from the lower levels of the mine. Consequently, the blasted ore tonnage for the June 2019 quarter exceeded mined (hauled) tonnage by nearly 300 000 tonnes.
Underground pumping systems are now installed and fully operational. In addition to underground pumping capacity, a surface water management programme has been established which is allowing the mine to intercept and remove a large volume of rainfall that would otherwise enter the mine during heavy rain events. The permanent primary ventilation system was installed and commissioned during the March 2019 quarter and has resulted in reduced re-entry times following blasts.
Syama is located in the south of Mali, approximately 30 km from the Côte d’Ivoire border and 300 km south-east of the capital, Bamako. It comprises not only the Syama Underground Mine but also the Tabakoroni Open Pit Mine.
An updated definitive feasibility study completed last year outlined an updated plan for the Syama Underground Mine which will extend the mine life at Syama beyond 2032 at a life-of-mine AISC of US$746/oz based on an underground ore reserve of 3,0 Moz. Once the Syama Underground Mine is fully commissioned, Syama will be capable of producing over 300 000 oz of gold annually.
Photos courtesy of Resolute Mining
