Mobile Plant

Blackhead Quarries: Improving plant flexibility, energy, efficiency and safety

Established in 1986, Blackhead Quarries is a joint venture between Palmer & Son (founded in 1880) and Fulton Hogan, and operates a number of quarries in the region surrounding Dunedin, on New Zealand’s South Island. Opened in the 1950s, the company’s Blackhead quarry, at Blackhead on the seaward side of Green Island, produces 300,000 tonnes per year.

The company also operates quarries at Logan Point, in Dunedin and Balclutha, plus the Walton Park sand plant in Fairfield.

{{image2-a:r-w:300}}The Balclutha Quarry, about 80km south-west of Dunedin, is the largest producer of quality aggregates in the South Otago area and supplies about 30 different products.

With a population of about 130,000 people, Dunedin is the second largest city of New Zealand’s South Island and the principle city of the Otago region, with the harbour and the hills surrounding it being the remnants of an extinct volcano. It has a diverse economy, but the city’s most important activity centres around tertiary education – Dunedin is home to the University of Otago, New Zealand’s oldest university (established in 1869), and the Otago Polytechnic.

While primary industries are the main economic drivers of New Zealand’s economy, in recent years the Otago region has experienced a large increase in tourism. As a result, local government authorities have increased their expenditure on infrastructure, driving strong demand for quarry products.

Future investment

Until recently, Blackhead Quarries’ Balclutha Quarry operated a fixed crushing plant that required rock to be transported up to 5km from its primary sources to the ageing facility.

In the interest of improving operational flexibility and safety, the company decided to invest in a new mobile crushing and screening plant for its Balclutha operations. Blackhead Quarries has extensive experience with Metso equipment, having bought its first Lokotrack mobile impact crusher in 2005. With its latest acquisition, Blackhead now operates the largest fleet of Metso mobile crushing and screening equipment in New Zealand.

But the company’s relationship with Metso and MIMICO, Metso’s dealer in New Zealand, dates back a lot further. Much of the equipment in the company’s original fixed plants includes Nordberg, Allis Chalmers and Barmac machines that can all be traced back to Metso origins.

{{image4-a:r-w:300}}Tony Hunter, the general manager of Blackhead Quarries, has been involved in the industry for more than 30 years and is a fifth generation descendant of one of the company’s founders. Hunter has overall operational responsibility for all the company’s quarries.

He said being near the sea, the Blackhead quarry’s fixed plant, which had been in place for more than three decades, was suffering from extensive corrosion issues. Management was worried about the safety of fixed walkways and the quarry’s 23 conveyors.

“Five years ago, we decided it was best to build a whole new plant at Blackhead with only nine conveyors and no walkways,” he said.

In doing so, a Nordberg C100 jaw crusher, a cone crusher and Barmac 9600 crusher were relocated.

The new plant is fully automated and was designed to keep the amount of structural steel work to a minimum, which led to the elimination of walkways.

“For maintenance we use cherry pickers, which give better access to the equipment than walkways and, in our opinion, are much safer for our maintenance staff,” he said.

Reliable wear part supply

Gavin Hartley, the quarry manager at Blackhead Quarry, has 10 years’ experience with the company. Hartley, who is a past president of the Institute of Quarrying New Zealand, describes his job as “making stones as cheaply and efficiently as possible” while ensuring his staff is safe.

{{image3-a:r-w:300}}“Staff compatibility and continuity are very important, as is giving our people the right tools for the job,” he said.

The Blackhead Quarry produces a full range of quarry products, including base courses (for roadbase), sealing chip, asphalt dust and railway ballast. Rock quarried in the Otago area is a heavy, fine-grained rock that is hard, brittle and abrasive.

According to Hartley, the jaws and liners typically have a duration of about 3500 hours, and Barmac tips only about 500 hours. “Bucket teeth can last anything from 800 to 2000 hours,” he said. Therefore, reliable, local supply of wear and spare parts is
very important.

Importance of local support

“Here in New Zealand we are a long way from Finland, or other countries where rock crushers are manufactured,” Hunter said. ”It’s important that we can get ready access to the support we need, because a crushing equipment failure can stop our production.”

{{image5-a:r-w:300}}Garth Taylor, the crushing and screening business manager at MIMICO, agreed.

“New Zealand is a small country and Dunedin is a small community,” he said. “If Blackhead Quarries has two LT106 jaw crushers, they only need one set of spare parts. They have two of New Zealand’s 12 LT1213 impact crushers. The significant population of Metso machines in New Zealand means that we keep a comprehensive range of spare parts to support our customers.”

While there are now more brands of crusher available in the New Zealand market than ever, Hunter likes to work with organisations that support the local quarrying industry.

“The large number of Metso crushers in New Zealand means that there’s good support locally,” he said. “Wear parts are one thing, but these technically advanced machines can be stopped by the failure of a small component like a sensor.

{{image6-a:l-w:300}}“While we perform most of the maintenance ourselves, it is good to have local technical support. MIMICO provides all that we need and we have a great relationship.”

Blackhead Quarries experienced the benefits of crushing and screening at the quarry face when it introduced its first mobile crusher in 2005. The company has been growing its fleet of Metso Lokotrack mobile equipment ever since, gradually reducing its reliance on fixed plant.

“You can’t bust a rock without energy and even though it is fuel-efficient, the mobile plant uses a lot of diesel – the machines have quite large motors to move them around, as well as for processing rock,” Hunter said.

“With our move to mobile equipment and reduction in the number of trucks, our diesel usage has remained about the same, but we no longer consume electricity in our fixed plants – so overall, our energy costs have gone down in the order of $[NZD]100,000 ($AUD94,700) per annum.”

According to Hunter, the reduction in truck usage has also delivered significant benefits in terms of staffing levels, site safety and maintenance costs.

{{image7-a:r-w:300}}Blackhead Quarries now owns 10 Lokotracks across its sites, and is the largest user of these machines in New Zealand.

“Our Lokotrack fleet has become very important to our business,” Hunter said. “Our original LT1213 unit was the first one in New Zealand and is still operating – and now we have more across our quarries. They are the core of our mobile fleet.

“We bought our first Lokotrack because, at the time, it was the best machine for the job. There weren’t as many options on the market as there are today. While we are always evaluating alternatives, we keep choosing Metso because of the strength of the back-up available through MIMICO, the great track record and reliability of Metso equipment, and the quality of product we can produce with Metso machines.”

Going mobile at Balclutha

The company’s most recent addition to its Lokotrack fleet took place in 2017 at its Balclutha Quarry, which mostly produces road and construction materials, plus manufactured sand.

A significant part of the quarry’s production also feeds the concrete plant next door. The quarry’s demand tends to be seasonal – the Clutha District Council, for example, has an annual road sealing season, and there are periodic maintenance gravel contracts.

{{image8-a:l-w:300}}Craig Upston, quarry manager at the Balclutha Quarry, is a veteran of the industry. Having been with the company for 25 years, he is a third generation employee.

“The shape of the product is critical for our customers – if we don’t get it right it will be rejected,” he said. “Our Barmac crusher helps us to achieve consistent product shape and quality.”

The Metso Barmac vertical impact crusher uses an autogenous (rock on rock) crushing method. Its adjustable rotor speed and feed rate give operators precise control of the grade and shape of the final product.

From Upston’s perspective, moving from fixed to mobile plant was a matter of future- proofing the quarry.

“We were planning to replace our older Barmac with a new one, and because the market for Balclutha’s product has a lot of ups and downs, being able to move the crusher around to different sites creates better business flexibility,” he said.

The quarry was opened some distance from the town of Balclutha, but with the growth of the town bringing suburbia closer, dust has become more of an issue. By eliminating the fixed plant that was close to the road and moving to Lokotrack machines, quarry staff can choose where crushing occurs. The reduction of truck movement and decommissioning of the fixed plant has made it much easier for the company to manage dust.

{{image9-a:r-w:300}}At first Upston proposed putting a new Barmac on tracks, then adding a tracked cone and jaw crusher in another five years.

As it turns out, the company’s management loved the idea and acquired all three Lokotrack versions in the same year.

Upston’s first exposure to Metso crushers was the Nordberg GP300, when Blackhead Quarries took over from Fulton Hogan in 2003.

“We already had a lot of Metso gear and had a great run with the crushers, so it made sense to keep on dealing with the same company”, he said.

“As we were happy with the Metso equipment that we already owned, it was a no-brainer.”

The decision to move to tracked equipment was driven by the need to quarry without access to electricity. Additionally, if the quarry had to relocate, it would be easy to move the equipment.

“If you bolt it to the ground there is no flexibility,” Upston said. “All the mobile plant is self-powered. We don’t have any three-phase power at the new quarry face, so mobile, diesel-powered crushing and screening is the only way to go.”

Reduced reliance on fixed plant

In July 2017 MIMICO supplied a Metso Lokotrack LT106 mobile jaw crusher along with an LT200HP mobile cone crusher and an ST3.5 mobile screen for the Balclutha Quarry.

{{image10-a:l-w:300}}An additional ST3.5 and an LT7150 mobile Barmac VSI (impact) crusher were supplied in October.

At a time of increasing infrastructure expenditure in the growing Otago region, being able to produce large quantities of quality aggregate in a more flexible way allows the company to be highly responsive to market fluctuations, which is important for Blackhead’s future success.

The company also deploys some of its Lokotrack mobile crushers and screens in contract crushing operations around the Dunedin area and is now looking to purchase another LT106 for a new job that will deliver 500,000 tonnes of aggregate for a major road building project.

Technology aside, Hunter sees his people as the company’s greatest asset. “There are all those buzzwords people use like safety, productivity and profitability, but it all comes down to people,” he said.

“We have a 25-year club here, comprising more than a quarter of our staff, which means a lot of experience.”

The Blackhead Quarries business is like a big family that has existed for five generations, and Hunter wants it to continue to succeed for future generations.

“It’s an intergenerational thing we have here, and as much as we get covered in dirt and dust, it’s a lot of fun and a very good life.”

{{image11-a:r-w:300}}In a world where concern for the environment means people look at mining and quarrying with an increasingly critical eye, Hunter has a positive outlook.

“This is a simple business. You can’t have a city without stones, and so we are lucky to be a mature company in a mature local economy that will always need infrastructure,” he said. “In buying the Lokotrack equipment, I am trying to set the company on a good path for whatever may happen over the next 10 to 15 years to come and beyond.”

Source: Metso Australia


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