Management

Supplier helps quarry boost production by 30%

Lafarge’s Pitt River Quarry in British Columbia, Canada, is part of a Lafarge North America network of some 900 offices and operations, with the company being the largest diversified supplier of construction materials in Canada and the United States.

The Pitt River facility is a Lafarge flagship unit located 50km west of Vancouver. That places it within the Vancouver metro area, which is a big market for the quarry. Situated near the banks of the Pitt River, it ships out between 1.5 million and two million tonnes of aggregate per annum, loading either river barges or trucks with the prized product. Reserves at the quarry are expected to last for the next half-century.

{{image2-a:r-w:250}}In 2013 operations at the granite quarry were running smoothly, as it churned out 900 tonnes per hour of high quality aggregate used in Superpave, asphalt, and concrete applications. When a main frame cracked on its 54-inch cone crusher, quarry manager Robert Brakes sought solutions to replace the quaternary unit, which was too old to warrant repair.

Among the offered solutions was one provided by ELRUS Aggregate Systems, the authorised Sandvik Construction dealer for western Canada. ELRUS had previously supplied a Sandvik S6800, the quarry’s secondary crushing unit.

DOING THE MATHS

ELRUS representative Mike Wikdahl believed the Sandvik CH660 stationary cone crusher, a common platform unit to the S6800, would be a perfect addition to the crushing system.

After he studied the company’s operation, Wikdahl went one step further. “We initially offered what our customer requested – a straightforward replacement of the quaternary crusher,” Wikdahl said.

But after studying several flow sheets, he proposed the quarry rearrange its line-up of machines to take advantage of the CH660’s finer product. Specifically, he suggested the company’s tertiary crusher be relocated to replace the broken cone crusher and the CH660 replace it in third stage crushing. He predicted an increase in production of at least 10 to 15 per cent from the added capabilities of the CH660.

Brakes pored over the flow sheets, bringing to his analysis the perspective of a third generation quarry operator with 27 years of experience in the industry. He recognised that Wikdahl had done a lot of research but said: “It still took me a little bit to read between the lines.”

In the end, Brakes came to the same conclusion – that placing the new crusher in the third position in the crushing sequence would boost output. That has proved to be the case.

“The CH660 produces aggregate of a good size for the next stage of crushing,” Brakes said. “Now the quaternary crusher isn’t dealing with 100mm to 115mm rock but with 65mm rock. The result is no pegging and a good flow.”

The quarry’s assistant manager Shayne Daum agreed size reduction turned out to be “a bigger thing” than originally anticipated.

He said Wikdahl’s analysis showed clearly that the previous quaternary crusher produced an operational bottleneck, as 100mm/h to 225mm/h crusher feed would overflow and be dumped to the ground, requiring additional handling.

“With the CH660, the unwanted by-product has gone from 1000 tonnes a day to zero,” he said.

The CH660 went online in January 2014 as a tertiary crusher, and the benefits to Lafarge Pitt River Quarry have been impressive. The most obvious is the sizeable upturn in total production, with the quarry experiencing a 30 per cent increase in aggregate output, reaching 1200 tonnes an hour. The increase was double that predicted by Wikdahl.

“Before, it was hard to hit 1000 tonnes,” Brakes said, adding that “the cost per tonne was the deciding factor. We typically were running a shift and a half to get the same tonnage as we now are doing with regular shifts. That’s huge when you add it all up – wear on belts, fuel, man hours and other costs.”

Another advantage for Lafarge Pitt River Quarry is better maintenance scheduling. Because of increased production rates, the quarry can afford regular planned maintenance interruptions, which also avoid costlier overtime repair work.

“Before we had to run around and chase maintenance needs,” Brakes said. “Now we can plan on scheduled maintenance programs.”

IMPROVED MAINTENANCE

Systematically maintaining the machinery has other positive implications for the company; now maintenance occurs regularly, budgeting for it is regular too, with the cost being spread throughout the year rather than coming in surges at sometimes inconvenient times.

The CH660’s design adds to the maintenance good news.

According to Pitt River crusher operator Nolan Wall, “changing out the liners is easier and faster, which is significant because downtime is a killer. That’s why I like the CH660, it’s reliable”.

The CH660 liners are also more durable than those on the crusher the unit replaced. Brakes said liners on the previous crusher lasted 650 hours on average.

“Now we are getting a couple-hundred more hours on a liner. This is impressive considering the Sandvik is doing more reduction, which means it is working harder.”

{{image3-a:r-w:250}}Stephen Dobler, Sandvik Construction’s business line manager for crushing and screening in Canada, said the CH660’s CLP manganese liners perform better overall because they are engineered to maintain intake capability and chamber geometry longer than the previous crusher.

The CH660 also benefits from more efficient power transfer to the crushing chamber, derived from Sandvik’s Hydroset technology coupled with the ASRi automation system, which maintains optimum reduction despite wear.

“These features ensure a customer can maximise reduction and reduce the amount of recirculating material, freeing up space to process more material,” Dobler said. “So the performance of the crusher and the quality of the product are more consistent.”

Breaking rock is a tough job, of course. Components do wear out from the constant grinding and can break down over time.

As the Pitt River Quarry manager considered the competing solutions and bids, he did so with one eye on service expectations.

“You cannot afford downtime,” Brakes said. “It can cost $USD10,000 ($AUD13,081) an hour if you are down, so reliable after sales service was important in choosing a crusher.”

ELRUS Aggregate Systems has an office within a reasonable distance of Pitt Meadows, where Lafarge operates its quarry.

That was important to Brakes.

“ELRUS is not far from us. If they don’t have a part, they typically will have it in Calgary where they are headquartered. That was a key factor in our decision.”

It also helps that the CH660 has some parts in common with the other Sandvik crusher in the quarry, the S6800. That makes it easier for the company’s maintenance department to keep an inventory of machine components on hand.

Furthermore, maintenance technicians can fully access the CH660 from above to inspect critical parts and service the machine, with the easy access speeding any work.

The combination of excellent advice from a trusted supplier and state of the art equipment from Sandvik Construction has enabled Lafarge’s Pitt River granite quarry to boost production. The maintenance features and aftermarket provisions have provided extra peace of mind, as well as allowing scheduled servicing to further boost productivity, thereby providing Lafarge with a vastly improved cost per tonne operation.

Source: Sandvik Construction

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