Perth-based Bulk Handling Technologies delivers heavy-duty FEL hopper and belt feeder for a lithium project in Western Australia.
Lithium demand is set to expand beyond current supply in the future. Tesla has suggested it will need 16 times its 2022 needs or 30 per cent more lithium than currently available by 2030.
The World Economic Forum has predicted global demand will reach over three million metric tonnes. In contrast, the world produced 540,000 metric tonnes in 2021.
It was clear to Bulk Handling Technologies’ Western Australian client that an opportunity existed in the lithium market if it could improve its system.
Planned increases in production at the site meant that a more reliable and higher capacity system was required to ensure uninterrupted feed of lithium ore.
The client had struggled for many years with an ‘off-the-shelf’ hopper and belt feeder. Bulk Handling Technologies was engaged to design and supply a new, larger capacity hopper suitable for feeding with a Komatsu WA700, which would prevent the delays experienced with material hang-up and poor hopper flow.
Sebastien Poulinet, senior mechanical design engineer at Bulk Handling Technologies, said there were key features to the new set-up.
“With a 6m long hopper, it is important to take account of the material properties to not only ensure mass flow but also to promote uniform draw-down along the full length,” he said.
“Without proper design, long hoppers can not only suffer hang-ups and bridging, but they can preferentially feed from one end, causing delays in re-loading and premature wear of the belt.”
Small-capacity hoppers for front-end loading (FEL) feeding are standard on mine sites and quarries. They are often based on a standard proprietary design and suitable for ‘typical’ bulk materials in many cases.
With minimal storage capacity, a small, standard hopper can seemingly work well, despite not being optimal for the material. However, if the same approach is taken with larger hoppers, they can cause expensive downtime and limit throughput.
Bulk Handling Technologies had previously helped a large gold mine that faced the same circumstances. FEL feeding was paused regularly so build-up in the hopper could be manually cleared.
Following a site audit and design review, material testing was conducted and Bulk Handling Technologies designed a new hopper.
The review results established critical hopper geometry, wall liner materials and head load conditions for the belt feeder.
Bulk Handling Technologies also carried out a review of the belt feeder design to determine the pull-out forces, discharge bed height and wall divergence angles required to ensure mass flow discharge along the entire length of the hopper.
The new design incorporated polished, bolted, replaceable Arcoplate liners, a single offset baffle and wall angles of 70 degrees.
Specialist material testing of a representative sample is always recommended to determine the range of potential flow properties when designing large feed hoppers.
Correctly matching the feeder to the hopper is essential to ensure reliable performance. This is even more important when dealing with materials that have difficult flow characteristics.
“An important criterion for both projects was the full recovery of the stored volume over a range for moisture contents,” Poulinet said.
“Uniform draw-down from the hopper was necessary to ensure there was capacity created along the full length during discharge to ensure the FEL operator could tip a full bucket without spillage.
“An uneven level in the hopper can create delays in refilling or spillage when the operator tries to refill.”
Designed to feed 225tph of crushed ore, the belt feeder was 19m long and installed at an angle of eight degrees. The design included side and back hungry boards and provision for a front spillage control plate.
The feeder was assembled and tested before it was sent to the site.