Inside the future mine

Scientists are developing technology that will allow hard rock mining to be carried out efficiently by smart machines controlled from outside areas of elevated risk

A major research area of Minerals Down Under is expected to focus on transforming mining by developing and introducing automated technologies.

The main goals of this sector of work include removing workers from risky areas, making mines of the future more efficient, and finding ways to access resources that are currently ‘stranded’ due to geological or other constraints.

One of the most exciting projects in this field is ROES, a new mining method being developed by CSIRO in collaboration with Orica Mining Services, which is part of the Australian company, Orica. ROES is being developed as a more economic and safer way of mining orebody types that use drill and blast for rock fragmentation within a stope.

Key advantages

ROES has been developed to solve many OH&S issues, reduce mining costs, and reduce the time to bring ore on-line and shift marginal mineralised zones from resource to reserve.

It seeks to remove operators to safer locations and improve operator and equipment utilisation through the removal of travel time. It also aims to improve mining performance by more accurate control over drilling and blasting, and by responding faster and more accurately to changes in rock conditions within the stope.

It will be able to measure changes in rock during mining and alert operators immediately, thereby avoiding long delays and maximising efficiency.

A Research Leader with CSIRO Exploration & Mining (CEM), Jock Cunningham, said the potential benefits of ROES are significant.

“First of all it offers greatly improved safety as mining staff can operate outside zones of elevated risk, controlling the machines remotely,” he said.

According to Senior Research Engineer, Ian Gipps, who has undertaken the ROES mine designs, “the automation will also mean improved drilling and blasting performance and a reduction in the amount of time it takes to bring ore on-stream”.

“Several studies have been completed and are underway comparing ROES to existing open stoping methods, and they indicate that our system can offer a reduction of about 50 per cent in the amount of tunneling required to access applicable orebodies. This conservatively results in a reduction of 10-20 per cent in mining cost/tonne as first order savings.

“The main feature of ROES is that it involves principally vertical or inclined access to the orebody rather than lateral access. This allows reductions in development metres required, smaller average development profiles and more efficient and effective use of development in both tonnes per metre and total metres.

“ROES will also provide remote controlled and ‘real-time’ survey options so that blasting patterns and stope shape can be modified easily during the production cycle if required,” Gipps said.

How it works

Rock fragmentation is achieved by drill and blast methods and this system includes integrated sensor technology for monitoring the mining equipment and stope environment.

The ROES method uses unmanned remote-control machines (such as the one pictured right), deployed from a shaft positioned either within or close to an orebody, which can drill, blast and recover ore.

Drilling and blasting are performed using automated platforms that are lowered and raised in the shaft, while rock extraction from the base of the stopes is via conventional drawpoints.

All of the equipment and the processes are controlled remotely, or by automation. ROES operators will be able to use on-line software to design blasting patterns, assess relevant mining conditions and monitor product quality.

A novel drill control method is being tested to improve remote drilling and report changes in rock type. Senior Research Engineer, Dr Gary Cavanough and Physicist, Mark Kochanek (both from CEM) have developed a method that keeps the drilling focused at the ‘sweet spot’ even through changing rock types.

Its a blast

The main advantages in the drilling and blasting arena are that no blasting energy is required to ‘throw’ the rock clear of the face as broken material falls clear of the face being worked.

The stope can be fired as single rings, multiple rings or as a mass blast. Also, as the blast face is advancing vertically not horizontally, the stope can retain most of the blasted material to act as support for the walls until the final extraction sequence. Hence, for most of the stope life the height of exposed wall can be lower than it is using other methods.

Hi-tech

The ROES technology development programme will use recent advances in communications, remote and automated equipment control, sensing and machine guidance, all proven in other projects undertaken by CSIRO and Orica.

Technology to place explosives remotely is currently being developed by Orica, with assistance from the CSIRO ICT Centre based at QCAT. This will be the third generation of remote placement technology.

According to Cunningham, “much of the necessary development work in drill control and equipment conceptual design has been completed and Orica is undertaking the development work in explosive placement to allow the complete removal of operators from the stope region during explosive placement”.

“The project is ready for detailed design and construction in preparation for pre-mining field trials. Opportunities are now available for mining companies to support the mining trials programme through AMIRA.”

The development model provides for parallel development of Orica’s explosive placement technology before being integrated into the ROES mining system. Risk analysis will be undertaken regularly throughout the development process.

ROES is a trademark of the CSIRO and is registered in Australia.

This article first appeared in CSIRO Exploration & Minings magazine earthmatters that can be downloaded from www.em.csiro.au.

Jock Cunningham

07 3327 4699

jock.cunningham@csiro.au

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