Minnovare Optimises Production for Leading Gold Miners
This was originally published online by Australian Mining on 23rd October 2019.
Above Image: The advanced technology company has rapidly established its Production Optimiser system in the gold Industry over the past 18 months by collaborating with the sector’s leading companies. Image Credit: Australian Mining
Collaboration can prove to be a critical part in the growth of a mining equipment, technology and services (METS) company.
Minnovare understands this better than most after launching the Production Optimiser system in mid-2018 to improve drill and blast efficiency and productivity in underground mines.
What started as an idea born off the back of its flagship Azimuth Aligner exploration system, Minnovare has developed a platform capable of saving or earning mining companies tens of millions of dollars a year.
Minnovare head of engineering, Ryan Stimpson, says the company was inspired to develop Production Optimiser when one of its North American clients asked about a way to optimise production drilling, similar to how the Azimuth Aligner system optimises exploration drilling.
“That is where the discussion started, because alignment accuracy on long hole drills is really important as to how well a blast goes off,” Stimpson says.
“Since that initial discussion the technology has transformed into a complete hardware/software system that optimises multiple aspects of the typical drill and blast process in underground mining.”
“Back in Australia we found some mining companies that were interested in collaborating with us to investigate further – it was just an idea at that point.”
Minnovare convinced the likes of Gold Fields, Evolution Mining and Northern Star Resources to trial the Production Optimiser… and they weren’t sorry.
Designed for installation on all production rigs and models, the technology proved it could substantially reduce blast hole drilling deviation during the trials.
Production Optimiser also showed it could reduce dilution and downtime, while improving overall fragmentation and ore recovery – thanks to a substantial improvement in drilling accuracy and the streamlining of the rig setup process.
The system engages with Minnovare’s Client Online Reporting Engine (CORE), which uses digital drill plans and plods that sync seamlessly with existing mine-planning software to deliver drill-data capture and analysis capability.
Here, Australian Mining looks at what Production Optimiser has achieved during its projects with Gold Fields, Evolution Mining and Northern Star Resources:
Partnering with Gold Fields
Gold Fields’ Granny Smith mine near Laverton in Western Australia offered an ideal site for Minnovare to test Production Optimiser with its unique characteristics.
The South African company mines the Wallaby underground deposit at Granny Smith, an orebody recognised for its flat-tabular shape and that requires a high degree of drilling accuracy to mine efficiently.
Before Production Optimiser, existing drill and blast designs involved drilling at up to a 20-degree fly angle on either side of the orebody, a challenge for the fleet of underground long hole drills using traditional methods.
Gold Fields introduced the Production Optimiser technology in mid 2018 and drilled a series of ‘trial’ rings in the same ore drive to compare drill hole accuracy when using the two methodologies.
After analysis of the trial, Gold Fields found that holes drilled using the existing process recorded an average deviation due to alignment error at the collar of 4.4 per cent and an average deviation at the toe of 4.9 per cent.
The holes drilled using Production Optimiser, meanwhile, recorded an average deviation due to alignment error at the collar of 1.5 per cent and an average deviation at the toe of 2.5 per cent.
In percentage terms, the new technology reduced average blast hole deviation at the collar by 68 per cent and by 51 per cent at the toe.
“The biggest improvement we found in the trial was the collar deviation – we made it much more consistent,” Stimpson says. “When we looked at the data side by side there was a lot of variation as far as the average being high.
“It gave Gold Fields more reliability and confidence that they would be drilling in the right direction and in the direction they designed.”
A star is born
Northern Star Resources engaged Minnovare to help the miner understand why so much time was being spent re-drilling holes at its Kalgoorlie operations.
The gold company had also observed a problem with differences between the drilling rigs’ onboard inclinometers. When one drill followed another in a stope, Northern Star was returning drill holes up to three degrees different when the output on the inclinometer read the same.
Minnovare, in collaboration with Northern Star and internal contractor Northern Star Mining Services, implemented the Production Optimiser system at one of its Kalgoorlie operations across three long-hole production rigs.
The new technology works independently of the rig’s on-board systems to deliver greater speed, accuracy and reliability in rig setup.
Meanwhile, the Minnovare CORE software automatically records data via an inbuilt digital drill plan and plod feature.
“Northern Star purchased the system and for the first two months we asked them to collate their data on the performance,” Stimpson says.
“For the first two months, it was the highest ore recovery they had ever seen in the life of the mine. They suggested that drilling more accurately was improving the recovery of gold.”
The increased drill rate and stope ore-recovery equated to an approximate 3.5 per cent improvement in stope turnover time.
“If that was maintained for 12 months, which we believe it has, Northern Star would get an extra 5000 ounces out of the ground, which is an extra $8.4 million in their pockets in terms of revenue from gold,” Stimpson says.
The two companies have strengthened their partnership following the trial to develop additional technologies that will increase operational efficiencies further – signing an official ‘collaboration agreement’ in August last year.
The Production Optimiser technology evolves
Evolution Mining has been able to address unplanned dilution with the increase in drilling accuracy that Production Optimiser delivers.
Dilution, the contamination of ore with waste rock and other material, is acknowledged as an inevitable part of the process of ore extraction.
With the added confidence in its drilling, however, Evolution can now experiment with design patterns to reduce planned dilution – not just on the most narrow vein stopes but on all stopes.
Over a six-month period, Minnovare conducted a series of trials at Evolution’s Cracow gold mine in Queensland to compare drilling accuracy.
Description: A rig equipped with the Minnovare technology at Cracow.
Image Credit: Australian Mining
Minnovare’s trials compared the existing rig setup processes and technology compared with Production Optimiser to study the impact this had on ore dilution.
The comparison first revealed the extent to which rig alignment impacted blast-hole deviation. The Production Optimiser technology was proven to limit rig alignment error at Cracow, reducing average blast-hole deviation and increasing the number of holes drilled within tolerance by 160 per cent, leading to a 62 per cent reduction in average dilution on stopes drilled with the new technology.
Evolution Mining subsequently implemented Production Optimiser at Cracow in the second half of the 2018 financial year, which guided the mine to a 10 per cent reduction in planned dilution in financial year 2019 compared with the previous period (from 22 per cent down to 12 per cent).
The gold miner’s management at Cracow attributed a significant proportion of the reduction to Production Optimiser, along with sequencing and planning improvements.
“It really helps with planning. For instance, for each stope you assume a certain amount of time that you are going to be trucking the dirt out – it might be five days,” Stimpson says.
“So, your planning gets affected as well. Evolution can plan with more confidence and be more sure of the return that they can get.
“Evolution has started changing the way they do the whole design process at Cracow, including setting up blasts in ways they wouldn’t have considered before. This includes introducing a ‘Zipper’ drilling pattern on their most narrow vein stopes, which reduces the average stope blast width in-line with ore body. You can only do this if you have a lot of confidence in your drilling accuracy. It’s a surgical approach to blasting.”
As a result, the impact on overall stope performance during the trials was significant, with notable reduction in average cost-per-tonne and increases in average return and return-per-tonne.
Minnovare plans to build off the foundation set with Gold Fields, Evolution Mining and Northern Star by delivering additional benefits with the Production Optimiser system in the underground sector.
The company continues to collaborate with mining companies to help them realise the potential of the system at their sites.
Evolution, for example, has taken advantage of being able to drill straighter holes by also drilling longer holes.
“The longer holes that they can drill, the further the spacing between those levels can be,” Stimpson says.
“That is really important in terms of saving costs on development. Instead of having to develop a tunnel, get down to a certain level and make another level 20 metres below, they can do it every 25 metres and make less levels.
“You don’t spend as much time and money developing tunnels. Instead, you spend more time moving the dirt out of the ground.”
The digital aspect of the Production Optimiser technology also means it is well suited for an autonomous mining future.
Production Optimiser already transfers digital drill plans and plods to and from rigs, back to engineering. But in mines that have implemented Wi-Fi capabilities, that ability takes on a whole new dynamic.
“If they have Wi-Fi in the mine they can do that live and then see live progress. Already, a lot of mining companies are asking to interact with METS companies that provide data analysis systems or schedule planning systems to feed data into those systems so they can display them live for analysis and continuous improvement.,” Stimpson says.
Minnovare’s plans for Production Optimiser point to a strong future of collaboration with the company’s mining partners, a fitting way for it to cement its growth aspirations.
This article also appears in the November edition of Australian Mining.