SOURCE: Loadscan | April 28, 2023
A recently released report has reinforced the economic and environmental value of a Loadscan load volume scanner.
The study (UNDERGROUND MINING; Economic benefits of load volume scanning of underground mining trucks) was conducted over a seven-month period at a Central Queensland underground gold mine by Professor Peter Knights and Maximillian Reuter from the University of Queensland in Brisbane, Australia. The data gathered over that period indicated a significant incidence of carryback, excessive fuel consumption and under-utilisation of equipment, all of which contributed to unnecessary operating costs and considerable lost revenue.
What is the Loadscan load volume scanner (LVS)?
The Loadscan Load Volume Scanner (LVS) is designed primarily for the civil construction sector and utilises eye-safe Lidar (light detecting and ranging) laser scanning technology, combined with proprietary Loadscan software, to measure the exact volume of material in the bin of a truck.
Loadscan’s Mine Payload Technologies division has further developed its Mine Payload Scanner (MPS) for mining applications using technology based on its LVS system.
Empty haul trucks are driven below an elevated scan head to create a reference scan in the database and then, when loaded, are scanned during every pass from the mine, with those scans compared against the reference image to accurately measure the volume of the truck’s load.
Because trucks don’t need to come to a complete stop during the scanning process, the MPS system allows for a time saving over the use of traditional weigh bridges, reducing truck cycle times, while installation, operating and maintenance costs of an MPS are also considerably lower than in-situ weighing systems.
Trucks are fitted with radio frequency identification (RFID) tags for automatic recognition and tracking, which allows for detailed real-time reporting and data acquisition.
The scan information returned can highlight underloading, overloading – negatively effecting revenue – or uneven loading, which can cause unnecessary stress and wear on truck components and substantially increase operating costs.
Carryback negatively impacts revenue
One of the most important factors that the MPS can highlight is the incidence of carryback (or haulback), where material isn’t discharged from the bin during unloading and is carried back into the mine portal, reducing effective payload and having a considerable impact on productivity and, ultimately, revenue.
By identifying carryback, the material can be accounted for, deducted from shift tallies where necessary, and removed from the bin to ensure accuracy and improved payload capacity.
Data for the study was gathered from four articulated haul trucks – three Epiroc MT6020 models with a rated capacity of 60 tonne, and a single Epiroc MT65 with a rated capacity of 65 tonne. More than 6,600 scanner readings were recorded over the four trucks during the seven-month period.
Carryback was identified in more than 60% of the trucks’ haulage cycles and accounted for more than 980m3 of payload over the duration of the study, with an estimated revenue loss of AUD$370,000 (more than AUD$630,000 annually)1.
In addition, figures were as high as almost 3,500-litres of additional fuel used hauling carryback over the study period, adding almost AUD$7,000 in estimated additional operating costs (almost AUD$12,000 on an annual basis).
“Mining across the world is coming under a more intense focus to meet increased Best Practice requirements such as efficient use of equipment, reduced operating costs and a wide range of environmental issues, which is why metrics such as carryback, fuel consumption and loading efficiencies are so important,” says Loadscan Managing Director Carey West.
Scans indicate underloading
You can’t manage what you don’t measure
MPS data showed the average load volume for the 60 tonne-rated MT6020 trucks was just under 26.53, which returned an average payload weight of slightly more than 48 tonne (based on an estimated bulk density of 1.82 tonne/m3). Isolated scans of the MT65 however, showed average volumes of less than 30m3, equivalent to a payload of just under 54 tonne – considerably below its rated capacity of 65 tonne.
Conclusions from the report showed that the capacity of the MT65 could be considerably better utilised by increasing the average load. Estimations show an increase of just 10% in the average load would be valued at slightly under AUD$1 million per year1.
“Inefficient loading cycles can have a huge impact on profitability,” West says. “The MPS provides real time data of every load with an accuracy of +/- 1% and, by identifying underloading, equipment can be better utilised and operators can be trained in more efficient loading practices.”
Overloading and uneven loading
Overloading of trucks increases both cycle times and fuel consumption, reducing efficiencies and adding increased stress to machinery components, especially if trucks are loaded unevenly.
Potentially due to the presence of carryback in the bin, just over 9% of the trucks recorded during the survey period showed load volumes that could be categorised as overloading, with load volumes skewed to the right-hand side of the haul truck (potentially due to the location of the carryback material).
Uneven loading can create excessive tyre wear, add unnecessary load to suspension components and create stress through the driveline.
The MPS allows operators to monitor off-centre loading by scanning the truck bin in four quadrants and generating visual warning indicators.
“Volumetric load scanning is an extremely valuable tool that can be utilised effectively to reduce mining operating costs and increase effective and efficient use of equipment,” Carey West says.
“This report, which has been compiled on the back of collecting comprehensive amounts of data, indicates very clearly that the Loadscan system provides vital and useful information for operators, allowing them to work far more efficiently, generating better bottom-line returns and reducing operating costs.”
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