Duketon, Australia. Out in the middle of the red sand desert of Western Australia, Regis Resources extracts gold at the Rosemont mine. A complete crushing and screening plant supplied by Sandvik helps to meet the mine’s production goals.
The flies are everywhere – in your face, on your boots and all over your clothes. They try to crawl into your nose, mouth and eyes. It’s sunny and hot out here in the middle of the Western Australian desert. But it’s autumn and approaching winter in this region, so the temperature is lower than a few months ago.
“This is nothing compared to summertime,” says Kenny Weller, construction supervisor at Regis Resources. “Then we have temperatures over 40 degrees Celsius, and there are many more flies everywhere.”
The Sandvik-supplied crushing and screening plant at the Rosemont gold mine in the middle of the red-coloured Western Australian bush lands is an integral part of Regis Resources’ efficient gold production. Think of mining as a tripod consisting of three equally important legs: extracting (exploration, drilling and excavation), haulage (loading and hauling) and comminution (crushing, screening and milling). Without support from all three legs, the mining tripod would collapse.
To make sure that the third leg at Rosemont was reliable and strong, Regis Resources chose Sandvik as its supplier for the crushing and screening plant at the site.
“The Sandvik crushing plant is an integral part of the gold mine,” says Mick Evans, project manager, Regis Resources. “It’s the first stage of the gold processing plant, and as such it’s very important for the whole mine that it has good reliability and performance. The main reason we chose the Sandvik solution is that it’s a tested design. We’ve used Sandvik equipment in our other operations in the past. I like the equipment – it’s good robust equipment, and I was confident that Sandvik would be able to deliver.”
About Rosemont gold mine
Rosemont was discovered in the 1980s and was partially mined as a shallow oxide open pit. Regis took ownership in 2006, and the updated ore reserve at Rosemont stands at 19 tonnes (664,000 ounces) of contained gold. Regis Resources Limited is a Perth-based gold production and exploration company. The company is a purely Australian gold miner, with operations at the Duketon Gold Project in the North Eastern Goldfields of Western Australia and the McPhillamys Gold Project in the Central West region of New South Wales.
Weller explains that 100 tonnes of ore will yield between 100 and 200 grams of gold. It’s an enormous undertaking to make the bullion that comes out of the mine.
Bernie Cleary, Regis Resources’ general manager at Rosemont gold mine, has overall responsibility for the mining project, from the pit to the processing plant and through the production of the bullion. He has been in the mining industry for 12 years and has worked at the Rosemont plant from the start.
“The process plant team and maintenance team commissioned the circuit over a period of around a week, and then the circuit was at full capacity,” Cleary says. “The plant was designed for 1.5 million tonnes per annum, and following a month of commissioning the plant was achieving almost 1.7 million tonnes per annum.”
Running the plant doesn’t require many people. One reason is that the crushing circuit is operated from the plant control room. The operator has a complete overview of the process thanks to the automation and control systems in place, including the Automatic Setting Regulation (ASRi) system on the cone crushers, the feed level sensors and the CCTV cameras. With the ASRi, the actual crushing load inside the crusher is continuously monitored. It also keeps track of liner wear. This makes it easy to plan liner changes and minimize interruptions in production.
Joel Marland is the maintenance supervisor at Rosemont. His tasks are to organize and supervise the maintenance staff for the general day-to-day servicing, maintenance and planned shutdowns.
“I’m just making sure the mine site is ticking along nicely,” Marland says. “I might need to change an oil filter or a breather. You just do that as quickly as possible and in a safe manner, and get the plant back up and running. It’s been running really smoothly.”
The operator and maintenance teams work in two 12-hour shifts to keep the plant going 24 hours a day, seven days a week. The personnel are away from home for weeks at a time, but the feeling on-site is friendly with genuine camaraderie. “Life’s pretty good out here,” Marland says. “You are really looked after, so you have almost everything you would ever want, but being away from your wife and family makes it hard sometimes.”
Regis formed the partnership with Sandvik four and a half years ago, starting with a Sandvik CH420 cone crusher delivered to the Moolart Well plant within the mining project area. Next, two Sandvik CH660 cone crushers, secondary and tertiary applications, were supplied at the Garden Well plant. Sandvik product support manager Marcus Benn has been along for the whole ride.
“After these deliveries we were contacted by Regis and asked if we were able to supply a complete modular crushing and screening plant,” he says. “We have efficaciously concluded that agreement at Rosemont, and it’s been a great success for both Regis and Sandvik.”
Sandvik fleet at Rosemont
• One Sandvik CH660 cone crusher
• One Sandvik CH420 cone crusher
• One Sandvik CJ615 jaw crusher
• One Sandvik LF2448D screen
• One stockpile conveyor
• One plant automation control room and electrical equipment
• Additional Sandvik conveyors, dust encapsulation, bins and feeders
Together with Sandvik, Regis has erected an extremely lean crushing site. The whole workplace at Rosemont is neat and tidy. “The process and maintenance teams do a terrific job at keeping the process plant tidy and orderly, so it’s always easy to make sure there are no issues developing at the plant,” Cleary says. “Also, the safety performance is excellent. There have been no serious incidents since commissioning the process plant.”
Safe, innovative crushers
Part of that achievement is that Sandvik paid a lot of attention to safe handling of the crushers when designing the products. They are made to be as easy to operate and maintain as possible. All service and inspection is carried out from above, which makes the work easier and reduces the maintenance costs.
Evans agrees that the safety features are convenient for the team’s daily work and help support their well-being. “From a safety aspect, I find that the Sandvik equipment fits in very well with Regis’s philosophies,” he says. “The maintenance accesses are good, and there are some really good innovations,such as access into the screen deck with a removable feed chute that rolls away, and drop-in platforms that prevent any chance of falling. Overall, I’m happy with the thought that has gone into the safety and the maintenance aspects of the plant.”
The job for the plant is to size the material to the mill. After going through the mill, the gold ore is transported with pipelines, in a slurry form, back to the Garden Well processing facility 10 kilometres away.
It’s been helpful for Regis that, in addition to the high capacity, Sandvik CH crushers are compact, which makes them easy to move and install.
“I decided to look for the Sandvik option for this processing plant in order to cut the initial capital costs and also the installation costs,” Evans says. “One of the issues we have on these mine sites is that they’re very isolated. There are also transport problems, and for the structural erection we have to have people on site and accommodate them. All those issues pointed me towards a modular-type plant.”
Benn describes the partnership between Regis and Sandvik as a smooth process that has brought valuable experience to both companies about what a plant like the one at Rosemont can offer. “It’s been a very pleasant experience for both Sandvik and Regis,” he says. “The project has run very smoothly, and we’re all happy with the results.”
Small footprint, huge success
The surroundings here are breathtaking, with wildlife around every corner. To commission a gold mine in the natural setting of Western Australia, a mining company needs to go through a highly detailed process. The enhanced environment, health and safety aspects of the Sandvik crushers have helped make it possible to meet the standards. “The environmental protocols need to be adhered to strictly, and to date it’s been completed successfully,” Cleary says.
Evans, who has been with Regis since 2009, thinks the environmental aspects play a big role when deciding what equipment to choose. “One of the things I like, in terms of the environmental aspect of the Sandvik plant, is that it fits within a very small footprint,” he says.
It’s true that the Rosemont plant is very compact. It’s also robust and reliable, which makes it a stable leg for Regis to rely on for the efficiency of the gold mine.
Sandvik solution: Crushed it!
The plant was designed, manufactured and supplied by Sandvik over a period of 12 months following the signing of the contract. Thirty-five weeks were devoted to design and supply, and the rest of the time was dedicated to installation.
The plant from Sandvik includes a primary station (bin, apron feeder and a jaw crusher), a secondary crushing circuit (Sandvik CH660 cone crusher and screen) for the first round of sizing the ore, and a pebble crushing station (a Sandvik CH420 cone crusher). Sandvik also supplied all accompanying feeders and conveyors. A key feature of the cone crushers is their automated control system.