Bardon Hill Quarry near Leicester in Leicester-shire is one of the United Kingdom’s oldest continuously operated quarries (Figure 3). Aggregate Industries have recently developed a new quarry extension at this strategically important site, extending mineral production for a further 27 years. During the initial 14 years of production, over 12 M m3 of overburden material must be progressively extracted. The extracted overburden material will be processed and conveyed for emplacement within the existing exhausted quarry to a depth of 125 m.
A road haulage solution is not permitted due to the generation of considerable CO2 emissions, whilst a conventional conveyor system would have been very costly due to the length and number of transfer points required to navigate the existing quarry haul roads. An innovative and sustainable solution was therefore required to minimise the impact upon local residents, wildlife and the environment.
Other operational constraints included the requirement to minimise the drop height from material discharged into the quarry and to allow continuous operation of the delivery conveyor without compromising the use of heavy mobile equipment to handle and place the delivered overburden.
To address these complex requirements of the client Aggregate Industries, the Austrian Doppelmayr company, Wolfurt, has developed a novel solution for the backfill system. The proven RopeCon® system, a combination of ropeway technology and conventional conveying technology, will span 850 m across the entire pit with track ropes. The belt which transports the overburden moves on these steel wire track ropes. The material can be transferred onto a second belt directly in the rope span. This creates a second discharge point at a distance of approximately 100 m from the first discharge point. Depending on where the material is needed, either the first or the second discharge point can be used.
To solve the problem of the drop height, a smart concept has been developed which gradually reduces the sag as the backfill progresses. The drop height can thus be kept below 45 m at all times to minimise the impact from noise and dust during operation of the system.
The contract was signed in March 2019 and the system was due to be operational in December 2020 where it transports approximately 1,000 t/h of overburden over a distance of 500 m.
Doppelmayr Transport Technology GmbH