Finding energy efficiencies
29 May, 2013 Vicky Validakis
With the widely discussed downturn taking effect on mine sites around the country, saving money and increasing efficiencies is now more important than ever.
And while making investments in new equipment may not be on company’s wish lists at the moment, new technology and investment in R&D means many products on the market may be able to reduce costs.
According to Sandvik, 40 per cent of mining companies power is used at grinding mills.: 80 per cent of the power is used to turn to mill and 20 per cent to crush material.
Driven by customer needs around reducing energy consumption whilst improving productivity, the company last month launched its new Vibrocone crusher, combining both crushing and grinding capabilities and offering up to 30 per cent energy savings compared with traditional systems.
“Whatever you know about cone crushing, chuck out the window,it doesn’t apply anymore,” said Marcus Benn, Sandvik Mining Australia’s regional product line manager.
Traditionally, the crushing and grinding process required different machines and technology to carry out the initial crushing, followed by the grinding and milling phase.
But the Vibrocone has been described as a ‘game changer’ for the industry.
The first to be released is the 400 kW CO864 with a capacity of 200-300 tonnes an hour.
“It is the next generation of crushing technology, combining the best conventional crushing and grinding principals to produce an unprecedented amount of finely crushed product,” Benn explained.
“For example, in existing crushers comminuation circuits with rod/and or ball milling stages, the Vibrocone crushers can replace the rod mills or act as pre-grinding units for the ball mills.
Benn said innovative technological advances meant the Vibrocone incorporated existing uses and improved on them to increase the machines productivity.
“With a cone crusher you get your smallest possible size at your smallest gap setting, with the Vibrocone because we are using a high pressure grind roll principal with a better material, we actually open up the Vibrocone and the gap doesn’t influence the size of the material coming out, it just increases the capacity,” Benn told Australian Mining.
“So we use the gap setting to actually increase or decrease the capacity, the actual product size is determined by the amount of rotations and amount of vibrations you put into that material.
“It’s completely opposite to what you would normally do,”
The Vibrocone crusher produces a much finer feed, allowing it to handle the first stages of grinding in a dry process.
The machine crushes particles between the liner surface in the crushing chamber and they also crush each other in a high pressure inter-particle crushing action giving it the ability to produce a P50=3mm mill feed.
“Traditional cone crushers have an eccentric sleave with eccentric push which is fixed and its not able to move, the Vibrocone has a vibrator and a balance mechanism which is similar to a screen and it vibrates at extreme speeds and its free to vibrate so it has grinding action on the bore mill and hypercursher around the cone crusher all in one and that’s how we get the fine reduction, Benn explained.
Before being released at MINEexpo last year, Vibrocone crushers carried out over 10,000 hours of round the clock commercial operations in copper, iron ore and gold sit
“We pulled out the old technology and replaced it with the Vibrocone technology,” Benn said.
“What we saw was P100 out-perform old methods by 25 per cent.
“Looking at a Pt of about 3mms, it outperforms old crushers by 100%.
“And your P20, it outperforms by about 200 per cent”
“The main emphasis is getting rid of the SAG mills and replacing them with Vibrocone technology.”
Benn said the savings in energy were high when using the machine.
“A greenfield case study of a mtpa copper operation in South America by Ausenco has shown that the Vibrocone solution is the lowest cost option, with energy savings in the range of 20 per cent relative to the SAG mill alternative,” Benn said.
“Sending a finer feed to the bore mill and reduces your power requirements.”
In Australia, Regis Resources has commissioned the crusher for use on their Rosemont gold project outside of Kalgoorlie. Benn said Sandvik is also in talks with other companies to implement the system.
“It’s great to have the Vibrocone here in Australia because Australia is the testing ground for most equipment,” Benn said.
The company is also researching ways to make the machines larger a requested by some of the bigger mining houses.
Mark Clifford, vice president of APC sales for underground hard rock and surface mining said Sandvik invested heavily in R&D to better support its customers needs and supply equipment that does the job better.
“Our engineers continually improve and look at ways to enhance the reliability of the machines,” he said.