Ore inspired

Mining operations are turning to increased control and automation to meet the raw materials needs of China.

Were he alive today, Deng Xiaoping would have a lot to answer for. As Premier of China from 1978 to 1989, he oversaw reforms in its economy that have transformed the country from a marginal player in the global economy into the world's third largest trading nation, behind only the US and Germany. But with it has come a huge rise in its demand for commodities that has sent prices soaring.

However, it's not the only culprit; China is now the world's biggest consumer of copper, aluminium, lead, nickel, tin, zinc and iron ore, among other raw materials. Since 1999, it has consumed two-thirds of the world's growth in output of base metals, and since 2002 it has accounted for half the world's growth in consumption of steel, copper and aluminum, almost all the world's growth for nickel and tin, and more than the world's growth for lead and zinc.

And it is now at the stage of industrialisation where, if the record of other tiger economies is anything to go by, its demand for metals is about to become especially high.

It's a similar picture with coal. China now burns more of it than the US, the EU and Japan combined, and its consumption is rising by 10 per cent a year. In 2006 alone, it built power plants with more capacity than the whole of the UK, and by mid-2007 it was building two large power stations every week.

This demand has pushed prices above historical records. In the past five years, the price of aluminium has doubled to more than $1.40/lb, nickel has tripled to about $10/lb and copper has quadrupled to $4/lb.

In the past six months, spot prices of coal - the price paid "on the spot", rather than forward-looking agreements - have jumped 50 per cent, and in late June and early July mining giants Rio Tinto and BHP Billiton struck separate long-term deals with Chinese steel mills that saw a near doubling of iron ore prices.

This in turn has had a dual, but in a sense complementary effect on mining companies.

Exploring new depths

While the pressure is on to improve the performance of their mines, high commodity prices have also made it worth their while to mine resources that were once considered uneconomic - although that means digging deeper in remote areas with poorer ore grades. And this is in the context of the perennial battle with chronic shortages of skilled staff who are willing to work in what are potentially hazardous areas.

So the industry is turning increasingly to control and automation. While not a new feature of mining - early implementations date from the 1970s - there has been a sharp rise in its widespread adoption in recent years. Systems were brought in from other industries and adapted for specific mining operations; now the industry is developing its own. New mines are being designed with automation in mind, and existing ones are being upgraded or expanded with retrofits.

One of the biggest players in this sector is Metso Minerals, part of Metso Corporation, which set up its process technology group 30 or so years ago. Dr André Vien, senior research engineer in the group, says: "Typically, most of our current business comes from retrofits. If the job is an expansion then we'll often work with the mine's EPCM [Engineering, Procurement, Construction Management] contractor - there's the issue here of integration with the legacy system, which EPCM companies often do not do very well."

Business is growing for Metso and other vendors, thanks largely to the price of commodities. The mining industry normally runs in seven-year cycles, where the prices of commodities rise then fall, with different commodities going through these cycles at different times, but this time it's different.

Dr Vien says: "At the moment, the industry is in a 'super cycle' - every commodity is at an historically high price - and that's because of demand, particularly from China and India, so a key driver for this technology is the need for greater performance in processing - anything that increases production.

"That in turn creates the need for a 'whole mine' or system-wide approach to automation, from finding the best way to get the stuff out of the ground to achieving the optimum balance in grind size of the ore and recovery of the minerals at the processing end."

Varying integration

Of course, no two mines are the same, so the extraction, transport, processing and distribution will vary, as will their integration, and this is reflected in vendors' products.

Siemens, another major player in the industry, is a good example here. It markets integrated but modular and scalable systems under the Simine name, elements of which were used originally in the food and motor industries, called Simine CC (Control Centre) for automating process control and Simine MES (Management Execution System) for online production planning.

Fellow vendor ABB stresses its integration credentials too, in the sales literature on its IndustrialIT suite of software modules and minerals "library" for control applications.

But it has acknowledged hat systems like these are "blind" without sensors to tell them what's going on. For example, Metso and Rio Tinto, one of the world's largest iron ore producers, say sensors are absolutely key.

Metso also says the biggest underlying challenge is the measurement of ore characteristics - size, hardness and so on - so it has developed a family of vision-based systems called Visio. Members of Visio can measure the size distribution of the contents of haul trucks, the particle size distribution on the conveyor belts feeding into the ore crushing and grinding stage, and especially the conditions in the froth flotation process used for separating minerals from waste rock.

As Dr Vien explains: "The main application at the moment is to measure the velocity of the froth, which is used indirectly to control concentrate grade and recovery. We can also measure the froth's bubble size and colour spectra as a more direct measurement of grade and recovery, although this is still in research."

Another important sensing application is in iron ore mines that produce lump ore.

"Oversize ore lumps become either unwanted waste or an expensive rehandling chore, so the system avoids this," says Dr Vien.

He says this system-wide approach extends to the use of RFID tags inserted down blast holes prior to blasting, which allow mine operators to measure the quality and nature of the ore from individual holes. This enables them to track specific ore types, such as oxides and sulphides in a gold mine, that require different processing and which can then be sent automatically to different parts of the process plant.

Integrating and optimising the processing is all about setting targets, Dr Vien says, plus the need for more intelligent control systems to account for any changes needed in the process.

"For example, we have an expert system that can look at the current operating conditions and then use that to look ahead at the next 20 minutes of operation to determine if the nature of the ore is changing," he says. "This allows the system to decide on the best course of action with respect to, say, the feed rate of the ore.

"The system is a combination of process model and rules. The model form is preset but its parameters change, or adapt, according to the current conditions. The rules, by contrast, are project-specific and are designed to change the operating strategy according to specific ore types but without actually specifying the ore type, which is inferred through the model and other measurements."

Improved automation

Commercial vendors are not doing all the running though.

Rio Tinto has a huge project in Western Australia to control a group of 11 iron ore mines in the Pilbara region from a remote operations centre (ROC) 1,400km away in Perth. When it opens next year, 380 staff will manage the mines via TV screens and using feeds on operational data into a command and control system. The centre will also control sets of driverless trains 2.5km long and carrying up to 25,000 tonnes of ore at a time.

Rio Tinto spokesman Gervase Greene says: "We're looking at ore production rates from Pilbara of 420 million tonnes a year after 2012, and you just can't achieve that without these systems. Automation provides considerable benefits in the mining of commodities such as iron ore, which are taken from pit to port in bulk in a similar fashion, so it would be odd if technological solutions were not brought to bear."

To export this output, Rio Tinto has two ports in north-west Western Australia that can handle 200,000-tonne Capesize vessels, so named because they are too large to go through the Suez canal so have to travel between oceans around Cape Horn or the Cape of Good Hope.

And, here too, automation is set to play a part, with the use of vacuum mooring at the quaysides, which is quicker and safer than line mooring and which Rio Tinto is introducing in the near future.

It's also another instance of applying non-mining technology to the sector - vacuum mooring is used around the world for ferries and container ships but until now, says Greene, not in iron ore mining.

Yet it is not automation so much as autonomy that's important, says Greene. He cites the example of a project between Rio Tinto and Japanese truck manufacturer Komatsu that uses a driverless collision avoidance system. This, he says, frees up the driver for safer and more value-added tasks, and lowers the manpower needed.

"There are issues of logistics and safety here - and the need to have equipment working 24/7 in hazardous areas," he says.

"The thing is, drivers need to be trained, but working in these conditions means most people stay on the job for only a few years, so we have to keep finding new people and training them. That's the way it is in mining."

Staff retention is a "colossal factor" for Rio Tinto, says Greene, and this is another reason it's setting up the Perth ROC. "It's not just about having all our managers in one place," he says. "If, say, we have a manager working in a remote area who has children of high-school age, they're going to want to put them in a school in the city, so moving them into the ROC lets them do that - and they stay with the company."

Developing technology

As in other industries, mining companies have established collaborative programmes with research organisations to develop the technology - which, Greene points out, is still in its early days.

Rio Tinto, for example, signed a A$10.5m (nearly US$10m) deal in early 2008 with Curtin University of Technology, in Perth, WA, to set up the Centre for Materials and Sensing in Mining, to develop and deploy technologies for Rio Tinto's open-pit operations. The centre will complement work being done at the Rio Tinto Centre for Mine Automation, a A$21m partnership with the University of Sydney, and is led by Dr Vladimir Golovanevskiy, a former head of the Mir space station project - a prime example of drawing expertise, as well as technology, from outside the industry.

One of the world's largest agencies in this respect is the Australian government's Commonwealth Scientific and Industrial Research Organisation (CSIRO), with whom Rio Tinto also collaborates, as does fellow mining "major" BHP Billiton.

New projects

The CSIRO runs initiatives called Flagships that focus on securing and developing national resources, including coal and metals - the aim of the Minerals Down Under (MDU) Flagship is to add A$1,000bn worth of currently uneconomic resources to Australia's mineral reserves by 2030.

So the CSIRO, through various integrated programmes, is pursuing projects such as new, geology-based underground coal mining techniques that allow tracking and keeping machines inside the seam, sensing and navigation systems for automating transport units in mines and smelters, and the automation of rock breakers. In 2003, Caterpillar launched its Minegem systems for automated control of underground load haul dump (LHD) units in metalliferous mines which used a CSIRO-developed guidance system.

"Most automation projects involve a spectrum of control from basic teleremote control through to autonomous control," explains Jock Cunningham, mining automation expert in the MDU Flagship. "Typically, each application will be able to operate as required in these different modes.

"The concept of geology-based guidance is interesting, and may do to mining what the use of X-ray fluorescence as an online tool did for the control of mineral processing plants," he continues. "But the mining application is more challenging because the key equipment is mobile and must deal with the product as it is found, although new sensors are being developed to respond to a relevant characteristic of the terrain ahead of a machine."

There are other challenges, too. As David Hainsworth, a programme leader at CSIRO Exploration and Mining says: "Logistics present the largest problem in R&D for mining equipment automation. Field work takes place at relatively remote locations, which makes it expensive.

"Also, because mining equipment is such a large capital investment, dedicated items are not available for experimentation. And in the current climate of high commodity demand, operational equipment cannot be taken offline."

Minimising risk

Whether the application is for coal or metal mining is less of a factor than if it is for use above or below ground.

"Generally, the sensing and automation issues present in open-cut coal and metal mining are similar," says Dr Hainsworth. "Perhaps the most significant additional challenge in underground coal mining is the existence of explosive risk zones due to the presence of methane and coal dust.

"Automation equipment can be designed so that it is intrinsically safe, but this greatly restricts the equipment's functionality and the development costs are very high.

"Also, while problems exist in using GPS to monitor and control the position of equipment in deep open-pit excavations, in underground mining it is not available at all. The paths equipment can take are limited to the tunnel network, and sensing systems to exploit this have been developed, for example in LHD automation."

Standards and integration are other issues - despite the claims from commercial vendors - with Cunningham citing the lack of industry-accepted standards for wireless communication for automation and control data, and disparate formats for orebody knowledge, as particular hurdles to overcome.

But despite these challenges the CSIRO is rolling out solutions to many mining automation problems. Its ROES project to deliver automated machines to drill and place explosives, and Smart*Cut super-hard cutting head system being notable examples of addressing a long-term industry wish for mining hard rock underground, removing operators from hazardous tasks and areas, and at lower cost.

Although Cunningham doubts there will be fully-automated mines in his lifetime - "that is not the key object; we need to be selective about the areas of operation suitable for automation" - he offers this encouraging prediction: "Control engineers will increasingly find a role [in mining] where they have not normally been used."

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