Automation in mining

Materials World magazine
,
2 Jan 2014

While automated systems are prevalent across a wide range of industries, the mining sector has been slower than many to embrace the technology. Branislav Lalik, Product Line Manager for Surface Materials Handling at Sandvik Mining Systems, tells Melanie Rutherford how automated systems can increase safety and productivity at mine and port sites.

With safety high on the list of priorities for mining companies, and recent research by Australia’s Government of Queensland Department of Mines showing that the lowest incidences of injuries or fatalities occur on sites with automated continuous mining systems, there is a strong case for the industry to embrace automation. According to Branislav Lalik of Sandvik Mining Systems, which specialises in automated systems for mining operations, the industry is a couple of years behind other sectors where automation is commonplace – in automotive manufacturing, for instance. Lalik argues, ‘Mining has always been conservative and traditional. Companies have a system that works and whether it is out of date or superseded is normally not a concern. In many instances it is not until they see other companies doing something different or they are losing money on the current process that the need for change is even discussed. When personal KPIs attached to site performance affect an individual’s pay packet, the willingness to try new approaches is further dampened.’

But the industry is changing, and what many see as hype is becoming increasingly widespread. Automation is replacing operators as the brain of the machines, with more and more equipment connected with programmable logic control (PLC) and supervisory control and data acquisition (SCADA) systems. Lalik nods to the majors Rio Tinto, BHP Billiton and Vale as examples of more forward thinking companies in the sector, who have already embraced automation on a wide scale. ‘The Rio Tinto operations in the Pilbara iron ore export ports, in Western Australia, demonstrates automation on a large scale. Since 2010, it has had a huge control centre in Perth (BHP opened its centre in July 2013) from which it controls multiple mine and port sites in Pilbara.’ Vale, on the other hand, has taken an alternative approach at its Carajás iron ore mine in the Pará region of Brazil. Here it has embarked on a truckless mining future, where the overburden handling consists of conveyor systems and fully mobile crushing plants.

While Lalik admits that this scale of automation is possible due to greater production volumes, smaller mining companies can also adopt automation to lesser degrees. He explains that there are three automation levels prevalent in operating mine sites (described above), which can be integrated according to a company’s production volume and budget.

Automation in action
The simplest way for a company to integrate automation at a mine site is through basic machine level, where different applications such as collision avoidance or stockpile profiling can be integrated into a machine’s PLC and SCADA system. These applications require state-of-the-art sensor technology based on radar, laser or GPS. Their signals are measured in real-time and allow operators to observe almost all areas of the mine operation, sometimes from the safety of a remote location. These auxiliary automation systems have use in several areas of a mining operation.

One example is automatic regulation of capacity control, where the system is programmed to detect which stockpile in the yard is to be loaded from and how many tonnes per hour is required.

Furthermore, clearance zones have to be defined to avoid interference with other machines – this is where further levels of automation can be added, with machine level communicating with system level and vice versa. ‘Should communications fail, sensors on the machine protect the equipment through active collision avoidance,’ explains Lalik. ‘While traditional systems react slowly and often stop when it is too late, radar and laser-based systems create both a pre-warning and an active stop. You can go a step further and have remote operation, locating the operator in a control room or remote centre away from the hazardous environment. This also enables them to operate more than one machine at a time, creating further savings in labour.

‘Laser solutions extend into real-time stockpile measurement, for accurate data on how much is being stacked and reclaimed at any one time. A laser scanning system creates a 3D stockpile model, which enables an operator complete visualisation of every stockpile and ensures each comprises what it should,’ says Lalik.

Automated detection systems are also increasingly prevalent in belt conveyor systems, where belt damage can cause significant delays in production. 2D lasers on the top and bottom runs of the conveyor measure in real-time the shape of the belt surface. This feeds back to a central control unit, where any failure is detected and the belt automatically stopped.

Another example of automation of bulk handling systems is the optimisation of stockpile reclamation. Here, 2D radar systems can scan and profile the stockpile shape during reclamation and proactively adjust key machine parameters, such as boom slewing speeds. This procedure enables consistent and efficient production, for example in coal handling, where the face of the stockpile is often prone to collapse.

In mining, the automated system of in-pit crushing and conveying (IPCC) is widely accepted as an economic and efficient alternative to truck haulage. Lalik explains, ‘The ore or waste handling system in an open-pit mine can comprise, for instance, a crusher station, belt wagon or connecting bridge and a spreader, all connected by conveyor systems. A crusher located close to the digging face will minimise truck haulage cycles and therefore costs. Whether the crusher station is fixed, semi-fixed, semimobile or fully mobile will determine the quantity of trucks required to feed this crushing station for ore or overburden as the case may be.’

The system components can be semi-automated (operators needed only to check for spillage or blockages in chutes, and to make minor tweaks, for example to line up the crawler tracks with the conveyor line) or fully automated (requiring only one operator to supervise the mining and the dump site).

Challenges to full automation
One area yet to make the transition to full automation is the loading of ships in the port load-out facilities of the mines. While Lalik says this will eventually come, issues such as a lack of proven state-of-the-art collision avoidance systems as the prerequisite for automation are slowing the shift to a fully automated shiploading process. ‘Moreover, it requires databases of loading plans and vessel types with all of the related geometries, says Lalik. ‘This is not easy, largely due to the communication between the operator and vessel captain, and the effects of load on the ship stability and motion add further problems.’ The biggest challenge, he says, is at the interfaces of the system control, where one automated process links with another. ‘This is where machine design and process know-how come into play, for example in the modelling of the vessel structure and its loading hatches, and its integration into the shiploader control according to its technical parameters.’

An added hurdle is that of finance. With installation of equipment requiring substantial capital expenditure, companies need to be sure of a worthwhile return on investment. Lalik cites benefits including heightened safety, greater efficiency and productivity, as well as increased serviceability of equipment (and therefore longer life) and reduced labour costs. He adds that automation doesn’t need to be on a large scale and that companies only need automate where necessary. The key, he says, is to start small. ‘Often there is no need to automate a whole process because the volumes are smaller. But it can be worth automating single machines, which will increase serviceability without influencing the rest of the process.

‘You can further increase the level of automation by reducing operator influence or even removing the operator completely – for example, with remote operation. First, this improves staff safety, as you’re removing them from the hazardous environment. Then you increase productivity, because automation allows 24/7 operation without shift changes, which, in turn, decreases operational costs. It also ensures a smooth, consistent operation with less wear and tear, which further contributes to lower operational expenditure.’

While for other sectors, such as the tooling industries, automated systems are adopted primarily to save on labour, the reasons behind mining companies looking to automate their systems are very different. ‘In mining, automation still requires the human element – you might have up to 50 operators in the control centre monitoring and running the system. The main reasons for removing the operator are safety and productivity. An operator has to concentrate for eight hours on a single machine and there are probably only a couple of points at which peak productivity is achieved. Consistent equipment loading rates can be as high as 20,000 tonnes per hour per machine, resulting in a substantial increase in revenue.

Changing attitudes

While several projects are currently underway to address technical barriers such as those surrounding shiploading automation, Lalik argues that a hesitance by the industry to adopt new and untried methods is further slowing progress. ‘Nobody wants to be the first to test the system – but you have to take some risks when it comes to being fully automated.’

One mining company that took such a risk is German electricity producer RWE, whose Rhenish lignite mines in the Cologne area play host to the world’s largest continuous mining system, which is almost fully automated. Why, then, are more mining companies not following suit? ‘The big issue is the education system from which the new generation of engineers come,’ says Lalik. ‘This new technology may be touched upon and even taught as a subject, but it has not yet become a core module at universities across the world. Each generation of engineers is trained in the same tried and proven methods, while new technology is sidelined to a few individuals or companies that are willing to step ahead of the competition and make a step change to their safety, environment, cost structure and productivity. It is just a matter of time. Who will be sheep and who will be goats in automation will ultimately determine who survives.’

 

For further information, email Branislav Lalik, branislav.lalik@sandvik.com

 

Automation levels: in a nutshell
Operational –
production planning and process control. The central place where
information about the whole network comes together and from which the
whole operation is supervised. This is where a company can maximise
system efficiency – for example, via precise monitoring of load in/load
out to enable calculation of optimum productivity. System – equipment
and material management. This includes equipment allocation, dispatch
and job assignment – for example, setting a stacker to roll to a
specific point on a certain stockpile and stack 5,000t iron ore per
hour. At this level only, a few operators supervise the systems
on-screen and intervene should a malfunction occur. Machine – integrated
sensor technology that enhances the operation of equipment, for
example, laser, radar and GPS. The technology will depend on the type of
equipment and its requirements. Some will still include manual
operation (for shiploading), while others can be fully automated for
continuous operation (for example, conveyor systems, stackers and
reclaimers).