Golden Bay Dolomite quarry high in the hills of Mount Burnett in Golden Bay is owned and run by Sollys Contractors. Site Manager Justin Balck knows the importance of reducing running costs and worked with Real Steel to find a clever way to do so.
Mount Burnett is the only location in which Dolomite – a Calcium Magnesium Carbonate occurring as a completely natural rock deposit is found in New Zealand. Sollys Contractors process the material into New Zealand’s finest Magnesium Fertiliser which is shipped all over the country for use in agriculture. It is a unique quarry site – the Dolomite resource is at the top of a steep hill and it is difficult to transport down to the processing plant.
“At Golden Bay Dolomite our main processing equipment is a Stedman Cage Mill Crusher which pulverises the Dolomite rock into smithereens. It costs a fortune to run especially when you combine a highly abrasive material that needs to be ground into such a fine product. We process approximately 50,000 tonnes of raw material each year,” says Justin.
“Around seven years ago, our rotor discs inside the Cage Mill were made of hardfaced AR400 steel and were produced in the same design as the OEM part. Hardfacing was time consuming and expensive. It resulted in uneven wear, so they needed to be removed often to be re-hardfaced and re-balanced. Frequent hardfacing led to fatigue and cracks in the base metal. The service life of these AR400 rotor discs only reached 100 hours before needing major repair work,” says Justin.
In 2014, Sollys Contractors began working with Real Steel – an international Hardox Wearparts member. Real Steel imports steel from SSAB (Swedish Steel) who is the world leader in high strength and wear resistant steels. Within the SSAB product range, Hardox is the most renowned brand in the New Zealand market. Hardox steel has a unique combination of both hardness and toughness.
“Our local Real Steel Sales Manager was an expert at measuring up our parts on site and recommending which grade of Hardox steel would suit the application best. Their designer redesigned the rotor discs and tweaked things until he came up with the best design. It was so easy to work with the guys at Real Steel,” says Justin.
“The new design was a laminated rotor disc made from Hardox 500. They also redesigned the base plate of the rotor upgrading it from AR400 to Hardox 550. In addition, a recess was machined into the disc to allow for Hardox 600 wear plate to be inserted where the main wear occurs,” says Justin.
“The results are incredible and speak for themselves. Total wear life of the rotor increased by three times. In fact, our laminated rotor disc won Real Steel the international ‘Hardox Wearparts Award’ in 2016 for innovative design and application success in the aftermarket. Real Steel used smart design – the newly designed parts required less machining and profile cutting, and some parts were laminated. Having a combination of different grades of Hardox also resulted in more even wear on the rotors,” says Justin.
“Hardfacing was no longer required which removed the hassle of re-hardfacing and re-balancing the rotors throughout the service life. The service life went right up to 300 hours before needing minor repair work. To this day we continue to re-order the laminated rotor discs from Real Steel and have several sets on hand that we rotate. Over the past six years, we have been making minor adjustments to the design to continuously improve it. We are incredibly pleased with the results – both downtime and running costs have reduced,” says Justin.
Sollys Contractors has a huge presence in the South Island – they employ over 140 staff, have 100 trucks on the road and offer a great variety of services. “We can do anything” is the Sollys motto which includes freight, contracting, aggregates, spreading, bulk cartage, stockfeed, storage, fertilisers and livestock. They have been around since 1928 starting out with freight being their core business. Sollys has also been in the quarry business for over 90 years and currently operates three quarries in the upper South Island.
Ed Solly of Sollys Contractors says, “Our focus with Real Steel is on our plant life by using Hardox steel which is effective. We have a quarry lorry especially built with a Hardox bin for carting the rock at our Golden Bay Dolomite site, and lots of Hardox trucks in our fleet for specific applications. The guys at Real Steel are friendly and easy to deal with. We are good at wearing stuff out, so it has been a good relationship for both of us.”
