Gearless conveyor drives proven for large-scale materials handling

How can large mines achieve their ambitious emission targets while keeping materials handling operations efficient? Gearless conveyor drives by ABB might provide the answer.

Reduction of greenhouse gas emissions from mining activities has increasingly become an important topic for discussion over the past decade.

According to McKinsey & Company’s ‘Climate Risk and Decarbonisation’ report published in January 2020, the current targets published by mining companies in Australia range from 0 to 30 per cent by 2030, far below the Paris Agreement goals.

In August this year, BHP called on its industry lobbyists – including the Minerals Council of Australia, the Business Council of Australia and the Australian Petroleum Production and Exploration Association – asking them to advocate for Paris Agreement-aligned emissions reductions.

Among the miner’s expectations are advocacy for targets that increase over time and aim towards achieving net-zero emissions by 2050.

Industry expert, Nik Gresshoff, says one of the ways by which mines can inch closer to their emission reduction targets is through adoption of new technologies for materials handling.

“If you want to achieve emissions reductions, you need to look at what technology are you going to use to get there? How are you going to increase efficiency in your existing material handling infrastructure to help you achieve that?” says Gresshoff, national sales manager with ABB Australia.

One of ABB’s latest innovations in this area is a gearless conveyor drive system, or GCD for short, which uses permanent magnet motors or conventional synchronous machines to replace the traditional gearbox conveyor motor system.

Gresshoff says the solution helps address many historic issues with the maintenance of gearboxes, while offering considerable energy savings over the lifespan of the mine.

“The gearbox is a main part of the drive system and if it fails, the system will be down for a long time. ABB has addressed this issue by eliminating the gearbox altogether, replacing it with robust, reliable control from variable speed drives running accurately performing, low speed motors,” explains Holger Rhoenisch, ABB’s system expert for material handling.

“Because the permanent magnet motors can produce the same torque power with 20-25 per cent less current than a traditional motor, you can reduce the number of motors needed on the drive system by combining the power demand in one permanent magnet motor – this would lower your maintenance and energy consumption considerably.”

A successful installation is at the Chuquicamata copper mine in northern Chile where they operate the world’s most powerful belt conveyor system. Gearless conveyor drives from ABB are used to operate a belt conveyor system with a design capacity of 11,000 tonnes per hour.

Eleven 5MW GCDs are used to drive three conveyors at Chuquicamata; two with four motors each and one with three motors. Two 20MW conveyors are used to transport the ore to the surface, overcoming a significant elevation change of about 1000 metres.

The second conveyor feeds into a slightly smaller, 15MW, overland conveyor. According to Gresshoff, conveyor designs with such high power are only made possible with gearless drives.

In Australia, Gresshoff says more and more mines are starting to embrace the total-cost-of-ownership concept, where the CAPEX cost is justified by the lifetime cost savings generated with the GCD.

“The savings on electricity consumption over the mine life are quite considerable and can easily outrun to CAPEX cost. On top of that, when you take into consideration the reduction in maintenance cost, that is where the GCD starts to become an even more attractive solution,” he continues.

Gresshoff says switching to the gearless drive system is something that mines with traditional drive infrastructure can also consider.

“If a customer wants to achieve higher energy efficiency and they are in the process of upgrading or repairing their existing geared drive train, why not look at upgrading to the GCD technology? It’s smaller, it uses less electricity and it’s easier to maintain.”

With a strong support from ABB’s service department, Gresshoff says customers can also consider a wide range of preventive and predictive maintenance solutions to further optimise their maintenance schedules.

“Our service departments and field service engineers can support customers through the lifecycle of the GCD technology, from installation commissioning, preventive maintenance, service contracts, digital connectivity, optimisation approaches and also to help with modernisation and consulting services,” he adds.

“ABB has been servicing multiple industries in Australia since 1906 with over 800 employees across different industries. We also have spare parts available through our service departments and we can also hold spares on site for customers. There is also the option to work out specific financial and leasing arrangements to interested customers.”

This article also appears in the October edition of Australian Mining.

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