A new Australian-designed and distributed acoustic sensing system – AURA IQ – is changing the way mines manage conveyor belt maintenance. It is much safer, more accurate and more efficient than conventional monitoring methods, and could save mining companies millions of dollars. LOUISE POBJOY reports
Maintaining conveyor belts in mines is a significant problem, with conventional monitoring methods unreliable, time consuming, labour-intensive, costly – and often hazardous.
Recognising the need for a better tool to identify and monitor conveyor belt wear, Australian mining research organisation, Mining3, has partnered with the AVA Group’s company Future Fibre Technologies to create the groundbreaking AURA IQ solution.
Equipment wear and tear - detecting and replacing
According to the AVA Group's group head of innovation for extractives and energy, Andrew Hames, the greatest maintenance burden for conveyor fitters is detecting and replacing worn rollers.
"Even a small width belt contains 2500 rollers per kilometre, and there are two bearings in each roller. A mine with 60 kilometres of conveyors can replace up to 40 rollers per day," Mr Hames says.
Mining3's data acoustics systems leader, Paul Wilson, explains that some mines employ up to eight staff to walk up and down belts three or four times a day to identify wear.
The tools they rely on – their hearing, infrared cameras or microphones – are flawed, because human hearing is unreliable; worn bearings don't always emit heat; and microphones pick up too much background noise or staff move too quickly to collect useful sounds.
Staff also face hazardous conditions and often can't access many sections of conveyor belts, which cross natural obstacles and rise on gantries to fill surge bins. In addition, bad weather can make it virtually impossible to walk the belts.
"Mine operators had no way of detecting bearings, so either replaced them too early which was expensive, or they'd collapse and cause damage, and that also becomes very costly," Dr Wilson says.
Using fibre optics to detect faults
AURA IQ was designed to address these problems. It comprises the Future Fibre Technologies' award-winning Aura Ai-2 fibre optic detection and sensing technology platform in combination with Mining3's advanced signal processing algorithms and data analysis.
The unique system transmits a series of short laser pulses along a single fibre optic cable retrofitted along the length of a conveyor. When bearings wear, they vibrate. Vibrations travel through the conveyor's frame and onto the cable, causing microscopic changes in the backscattered laser light.
Data from these changes is simultaneously gathered from every metre of the conveyor, and AURA IQ processes this data and alerts operators, on-or off-site, about potential failures.
AURA IQ's data can detect a broken ball or cracked cage in a ball race, observe and track idler bearings as they wear, and predict bearing seizures.
"The Aura IQ Cloud and network solution wirelessly connects the IQ Edge Server to a central cloud reporting and analysis platform," Mr Hames says.
Real-time alerts and reports anywhere in the world
"Alerts and reports from conveyor assets – located anywhere in the world – are accessible on any internet enabled device in near real time, without the need for specialist software or equipment."
The research behind differentiating sounds and categorising them into the different stages of a bearing's lifecycle is brand new, and as Dr Wilson tells us, it's game-changing.
"This is a radical idea. We've completely changed how we monitor the signals from bearings," Dr Wilson says.
METS Innovation Award finalist
It seems that others agree, with AURA IQ being a finalist in Austmine's 2019 METS Innovation Award and winning Mining Magazines' Bulk Handling Award in 2018.
AURA IQ's success could come down to it reducing the number of belt walks needed to maintain conveyors, significantly improving mine safety and occupational health initiatives.
Improving worker health and safety
"Fewer belt walks means staff have less risk of fatigue, heat stress, and exposure to noise, dust and atmospheric contaminants," Mr Hames says.
"The chance of injury from exposure to moving machinery, challenging environments and extreme weather also decreases."
And because fewer staff are needed for belt walks, their time and labour can be focused elsewhere. Dr Wilson believes this will improve overall mine performance.
"You can divert spare staff hours onto long-term maintenance jobs and get plants running more efficiently," Dr Wilson says.
Aura IQ delivers deeper insights into conveyor perfomance
Aura IQ's daily asset reliability reports will also help improve mine performance by giving maintenance technicians, site personnel, regional operational hubs and global headquarters deeper insights about every conveyor, at every site around the world.
The data in AURA IQ's reports is inherently reliable, accurate and independent, because it doesn’t rely on conventional monitoring and subjective interpretation.
"The fibre optic system is far, far better than human senses," Dr Wilson says.
"The signal processing and the mathematics we use takes all the noise and interference away and reveals just the diagnostic signals for the bearing conditions."
Better data means big financial and time savings for mines, because they can accurately predict when bearings will wear and schedule maintenance.
"Unscheduled stoppages cost a lot of money. When your plant is turning over a million dollars a day, the last thing you want is the conveyor belt to shut down for eight hours," Dr Wilson says.
Cost-effective equipment management
Predicting bearing wear also offers other financial benefits, including not wasting money on changing good bearings unnecessarily, and minimising failures that can lead to fire and expensive conveyor repairs.
Dr Wilson explains it's been over four years of hard work to get the technology to this point because it's so complex.
"It has a lot of mathematics, signal processing and two different expert systems in it. We're starting to do some machine learning and artificial intelligence as well, which will be fitted in the next generation tool."
The AVA Group ultimately aims to develop AURA IQ into a complete conveyor health monitoring solution. Improvements have already started, with the integration of vibration, temperature and current draw monitoring of conveyer motor drives and pulleys.
AURA IQ has already undergone four highly successful trials in Australia and two 'first adopter' production trials – one in Queensland and one in South America.
And while there aren't many industries that use conveyor belts to the extent that mining does, there has been strong interest from the bulk handling, energy, manufacturing and engineering industries.
"We have very strong interest from 18 countries across six regions that our technical support team are working through now. The return on-investment models completed are extremely compelling," Mr Hames says.