Crushing the stereotype

Ction Low costs and increased efficiency. The phrase sounds simple enough, but it is easier said than done.

mining companies want lower capital costs with fewer pieces of equipment and higher capacity from each unit even if the equipment is disposable after a reasonable service life.

Operating cost efficiency is an important factor driving change.

The globalisation of the mining industry and rationalisation of equipment vendors has also seen technology development and diffusion on a global scale.

Metal prices have fallen in real terms, ores being mined are lower grade with higher throughputs although power and labour costs have increased significantly.

There is also a trend for vendors to work closely with the end user and provide technical and after sales support while feeding operating data back into the design of new equipment.

Metso Minerals’ Asia distribution general manager John O’Reilly told Australian Mining another trend for vendors has been to move from equipment supplier to solution provider.

“Minesites don’t want machines, they want results,” O’Reilly said.

“If someone is an iron ore producer, they don’t just want a crusher or a screener, they want iron ore. They want a solution that can help them achieve maximum gain with minimum effort.”

According to O’Reilly, a good relationship between supplier and client is paramount. If there is no relationship, there is no business.

“A lot of companies will supply a mine with a piece of equipment and then it is up to the minesite to employ a contractor or the like to operate the machinery . This can often result in double handling.

“Turnkey solutions are definitely the way of the future. Suppliers are not only able to supply the equipment but also design, engineer and build a project from the ground up,” O’Reilly said.

“Turnkey solutions remove the double handling and save a minesite a lot of confusion and a lot of hassle.”

Advancing design

According to CSIRO Minerals’ Processing and Agglomeration research program leader Jonathan Campbell, the biggest developments in crushing and grinding practices over the last decade have been increased research and take-up of high pressure grinding rolls technology.

“Other big developments include the increased use of on- line plant instrumentation coupled with advanced process control,” Campbell said.

The level of process control and automation has increased in many crushing, grinding and screening practices.

“Automation removes personnel while at the same time reduces downtime and increases yield,” O’Reilly said.

“Today and into the future, we will start to see more machines interconnected using Programmable Logic Controllers (PLCs). These devices provide instant feedback on the productivity and effectiveness of the machine.

“Clients no longer need to wait a week for results to come in. They can get a birds-eye-view of what is happening in real-time. This gives them ultimate control, which paves the way for greater productivity, increased yield and greater reliability. By interfacing each machine with the next, clients are able to maximise the use of the machine,” he said.

While the future looks to be heading towards greater automation, machines are not about to replace man.

According to Mel King of West Australian-based mining equipment and supply business Minspec, many minesites are not comfortable moving into a future of automation, preferring to stick to old-fashioned reliability.

“Minesites don’t necessarily want and need the latest gadgets, rather, they want a reliable, hardworking machine whose life cycle will outsee the mine,” King told Australian Mining.

“First and foremost mine operators want competitively priced parts, they don’t want to be held to ransom.

“They want the right machine for the job and they want good product support.

“The industry continues to go through this phase whereby they believe clients want high performance, lightweight machines. Often, however, clients are after reliable, heavy duty machines that can operate under pressure, handle the work load and outlive the mine,” he said.

Metso Minerals will launch a new high performance tone crusher in November.

With a combination of optimized speed and large throw, the crusher is said to provide the highest reduction ratios of any current cone crusher.

All the improvements, however, have been made without increasing the size or bulk of the machine.

“It doesn’t challenge what people already know and are accustomed,” O’Reilly said.

“The crusher is delivered in the same envelope, but it produces greater yield and a greater performance.”

Back to the future

Jonathan Campbell of the CSIRO Minerals said regardless of what the latest technological advancements have been in quarrying, crushing and screening, the most important thing is for operators to be confident in their equipment.

“Mine operators need to know their equipment will meet the necessary availabilities and maintenance targets that their operation demands, but also that the process performance is sufficiently robust to handle the usual process variations that occur on plant,” Campbell said.

The CSIRO Minerals Processing and Agglomeration program is currently undertaking research in a wide range of areas including ore characterisation, crushing, AG/SAG mill optimisation, applications of high pressure grinding rolls and fine grinding technologies.

All of the research programs are underscored by the same theme – to make crushing and grinding technologies more efficient.

“With more energy efficient crushing and grinding technologies being adopted, the competitiveness of operations will be enhanced. There will be an increasing need to better understand the ore being processed so that the correct choice is made on the process flowsheet and the unit operations therein. This means that better on-line information about the process state particularly in high areas such as grinding will be critical in improving performance,” Campbell said.