Blackhead Quarries – Improving plant flexibility, energy efficiency and safety

Blackhead Quarries has extensive experience with Metso equipment, having bought its first Lokotrack mobile impact crusher back 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 exclusive dealer in New Zealand, dates back a lot further than that. Much of the equipment in the company’s original fixed plants includes Nordberg, Allis Chalmers and Barmac machines which can all be traced back to Metso origins.

Tony Hunter is the General Manager of Blackhead Quarries, he has been involved in the industry for over 30 years and is a fifth-generation descendant of one of the company’s original founders. Tony has overall operational responsibility for all of the company’s quarries.

He said that being near the sea, the Blackhead quarry’s fixed plant, that had been in place for over 30 years, 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, the existing 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.

Gavin Hartley is the quarry manager at Blackhead quarry, and has 10 years’ experience with the company. He describes his job as “making stones as cheaply and efficiently as possible while ensuring that his staff is safe.”

“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 road base), sealing chip, asphalt dust and railway ballast. The rock quarried in the Otago area is a heavy, fine-grained rock that is hard, brittle and abrasive.

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

The importance of local support

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

Garth Taylor, Crushing & Screening Business Manager at MIMICO, agrees: “New Zealand is a small country and Dunedin is a small community.”

“If Blackhead Quarries has two LT106 jaw crushers they only need one set of spare parts,” he explained. “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 before, 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. 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,” said Hunter. “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 $100k per annum.” According to Hunter, the reduction in truck usage has also delivered significant benefits in respect to staffing levels, site safety and maintenance costs.

Blackhead Quarries now owns a total of 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,” said Hunter. “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 backup 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 as well as 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.

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 originally opened some distance from the town of Balclutha, but with the growth of the town bringing suburbia closer to the quarry, the issue of dust has become more of a problem. 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.

At first Upston proposed putting a new Barmac on tracks then in five years’ time adding a tracked cone and jaw crusher as well. As it turns out, the company’s management loved the idea and acquired all three Lokotrack versions in the same year.

Uptson’s first exposure to Metso crushers was the Nordberg GP300 when Blackhead Quarries took over from Fulton Hogan around 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 elsewhere. “If you bolt it to the ground there is no flexibility,” he 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.”

Reducing dependence 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. 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 business 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 half a million tonnes of aggregate for a major road building project.

A positive outlook for the future

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 inter-generational 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.”

In a world where concern for the environment means that people look at mining and quarrying with an increasingly critical eye, Hunter has a positive outlook on the future. “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.”