New Gold Inc. has recently hired a mining contractor to work on expanding their operations underground at the Rainy River Project, with the aim of increasing yields.
New Gold's technical services manager Darrol Van Deventer said the move underground was always part of New Gold's plan and the Rainy River Project should be seen as a combined open pit and underground operation.
The underground project is on track and set to begin around August of 2019.
Van Deventer notes there is a real sense of excitement among his colleagues at the mine.
“I think there's an excitement, a bit of a buzz around Rainy and around the group for this underground project,” he enthused.
Work on the “portal” or entrance into the underground mine began two weeks ago and is about 90 percent complete, according to Van Deventer.
The entrance is made using a “box cut,” which is a small open cut that is created to provide an entrance point to a slope in an underground mine.
From the box cut, Van Deventer said they will dig on an incline until they intercept an ore body.
Unlike New Gold's open pit mine, the underground operations will be more accurate in their extractions.
The only minerals being withdrawn from the underground mine will be ore that is available for treatment.
The underground operations are in stark contrast to New Gold's current open pit mine where just over 130,000 metric tons of volcanic rock are extracted each day, equating to just over 291-million pounds.
New Gold's haul trucks transport roughly 600 truckloads out of New Gold's open pit mine each day with each load weighing about 220 metric tonnes.
The higher grade ore and some rock is sent to the mill for treatment while lower grade rock goes to the stockpile to be treated at a later stage.
The remaining rock is then routed to a waste dump.
Apart from the expansion, New Gold has also been able to considerably increase the efficiency of their open pit operations in the last year, Van Deventer lauded.
“The quality of mining has improved as the guys gained experience and it's not only the operational guys out in the field who are gaining that experience, but even the technical team,” he noted.
He explained that the New Gold team at the Rainy River site have developed stronger relationships and have learned how to work together more effectively.
“Specifically on the mining front, I think we have seen an improvement in performance and delivery to plants," Van Deventer said. "Things have definitely improved predominately in those spaces.”
A major factor in the improved performance for delivery from the open pit mine to the treatment plants is the increased life span of the haul truck's tires.
“We've seen large improvements on that front, and that's specifically been one of the success stories at Rainy River,” Van Deventer smiled.
“We officially started off with very poor tire life and that's improved to the position where we are now.”
From January to July of 2017, the average life span of a tire was just under 1,750 hours.
Fast forward one year later, and the tire's life span has increased by 1,800 to about 3,550 hours.
With each tire costing roughly $43,000, the doubling of their lifespan will go a long way.
Moving forward Van Deventer says New Gold has plans to increase capacity on the processing side of the Rainy River operation.
“We're having a look at increasing the current capacity our mill holds [and] processes at the moment,” he said.
The mill currently treats roughly 21,500 tonnes of rock a day and the plan is to expand their throughput to a steady rate of 24,000 tonnes a day.
The expansion project is coming along on time and adjustments to the back end of the process facility are expected to be completed by the beginning of October which will result in an immediate increase to the facility's throughput rate.
New Gold expects to continue their mining operations at the Rainy River site for approximately 13 more years, wrapping up in 2031.