Mobile Plant

A Kiwi?s Quarry Tour of Southern Australia

In 2010, I was fortunate to receive the Rocktec Innovation Award at that year?s QuarryNZ conference. The Rocktec Innovation Award allows the recipient to travel and further their knowledge in the quarrying industry to a very generous sum of $NZD5000 ($AUD4372). Rick Johnson, the CEO of Rocktec, wanted to acknowledge and foster innovation in the quarrying industry, the same innovation that had led to the development of one of the first VSI crushers ? the Barmac ? by Jim Macdonald and Bryan Bartley in New Zealand in the 1970s.
I arranged the study tour in collaboration with Rocktec and it comprised a tour of quarries in Victoria, South Australia and Tasmania. The 2011 tour included visits to operations managed by Fulton Hogan, Hanson, Boral, Southern Quarries and Hazell Bros.
My first flight of many departed Dunedin 15 minutes late but arrived on time in Auckland. I was hoping this was a good sign for the rest of my journey. The Auckland to Melbourne flight left 20 minutes late but arrived 10 minutes early. Customs was a breeze, no geckos or duck tongues in this traveller?s bag! I had a rental car booked from Hertz, so you would think the pick-up process would be easy. No it wasn?t. I now believe rental car people are worse than car salesmen!
{{image2-a:r-w:200}}Normally I like driving but not in a strange location or in the dark or especially when it is raining. Yes, you guessed it, by the time I hit the road, it was my first time in Melbourne at night and raining. No problem, I thought, the GPS will direct me the 3km to the Ciloms Airport Hotel. Boy, was I mistaken, as 20 minutes later I  arrived at the hotel. My tour of hard rock quarries began the next morning.
My guides at Tylden Quarry were Todd Frith, the quarry manager, and Josh Blain, the quarry supervisor. The plant configuration at Tylden was an LT105 jaw, an LT1213 impactor, an LT300HP cone and a 7150 VSI, with various screens. The mobile plant included two WA470 wheel loaders, a Hyundai 770 wheel loader, a ZX470 Hitachi excavator and a 771 dump truck. The plant produces up to 400,000 tonnes per year.
The quarry consists of a basalt rock formed in four distinct flows. It is one of the oldest quarries in the area and was operated for 84 years by a family prior to Fulton Hogan acquiring the pit.
The quarry is ideally located, surrounded by no other quarries. Tylden?s environmental issues are no different from other quarrying operations and include negotiations with neighbours and indigenous people.
The tour guide, quarry manager Dave Walker, is an old schooler of the industry who knows his quarry inside out and gets the best out of his plant and people. The quarry works a single bench of basalt rock covered by up to 4m of overburden and underlain by a second class lava flow, with a high water table.
{{image3-a:l-w:200}}Rock is loaded on to Caterpillar 773 dumpers using a Komatsu WA600 wheel loader feeding a Pegson jaw crusher. The plant has a Jaques secondary gyratory and Kawasaki KFS1000 tertiary with associated screens. Some products are dropped in bins while others are stockpiled on the ground. The plant has a capacity of 250,000 tonnes per year.
Boral has in the past two years had a modern plant installed at Dunnstown Quarry. At the time I visited the plant, it had just been commissioned and Rocktec was ironing out the bugs of a very modern, well laid out plant.
At Dunnstown, the basalt rock is blasted and fed into a mobile C125 jaw by a Caterpillar excavator. The primary crushed rock is discharged on to a field conveyor system, using a combination of Metso and Rocktec products. What surprised me was how quiet the field conveyors were. You had to look hard to know if the conveyors were actually running. Boral is currently working to a LEAN process, a system to identify the best way to carry out its operations to a high quality, safely, at the lowest cost. The plant has a capacity of about 650,000 tonnes per year. Boral?s spending did not stop on a new crushing plant but also included a budget for environmental work and rehabilitation of worked out areas. One of the innovations that had been incorporated into the plant was the use of hydraulics to move screen chutes out of the way for screen changes.
In New Zealand, our hard rock quarries are located on prominent hills, well in the view of the public. Of the three quarries I visited on the first day of my tour, I noted that unless you were looking for them, you wouldn?t have known they were there, as they were basically excavated into a flat paddock. All appeared to have issues with the water table, being just below the current quarry floor, and as a result the quarries have large footprints. All three were still dealing with water from record rainfall and flooding that occurred in January 2011.
The first day was interesting. The winter weather wasn?t disruptive (10 degrees, overcast and drizzle at times) and my trusty GPS only let me down once (unknown to me there are two Yendon Roads in the area of Moorbool, Victoria, and it was just my luck that I went to the wrong one first!).
{{image4-a:r-w:200}}CHIPPER ROAD TRIP
I stayed in Ballarat before driving to Adelaide the next day. The weather slowly improved the closer I came to Adelaide, rising to 16 degrees. I slightly regretted the decision to drive to Adelaide as one of the most exciting things on the drive was the change in sealing chip colour from basalt to granite, a light brown colour that glistened in the sun along the way. Being a quarryman, I didn?t stop at points of historic significance, I stopped at road side stockpile areas to have a look at these chips! As they are not washed, the chips are very ?dirty? compared with New Zealand. The chips also have issues with aggregate being contaminated with seeds, as also occurs back home. I also stopped at a road construction site where I could see the site foreman bouncing a wooden stick on the newly compacted aggregate sub-base. 
He swore this method had never failed him. The stick, apparently through a combination of bounce and sound, showed him if the sub-base was compacted correctly!
I really enjoyed the city of Adelaide. All the footpaths are made of pavers, some more level than others (and certainly no good for the ladies if they are wearing stilettos!). The economy must be good, as there were a number of tower cranes working in the CBD on new multi-storey buildings.
Rocktec had previously undertaken some work on the new plant at Sellicks Hill Quarry and the two companies have formed a great business relationship. My guides, Southern Quarries CEO Brett Brown and quarry manager Trevor Smith, were very accommodating and Brett went out of his way to look after me in Adelaide. The quarry has a number of rock types present, with shale and limestone the most quarried. When the quarry expands it will start excavating yet another high grade limestone. It has an amazing 150-plus years of reserves at about 450,000 tonnes per year.
A C140 jaw to a large surge pile handles primary crushing at the site. A HP400 and two HP300 cones carry out secondary crushing while tertiary crushing is done with a Barmac. Rocktec built the tertiary plant and helped with installation of the secondary plant. The quarry works to a number of environmental conditions, one of which is to meet a visual criteria from four locations down on the lower area in front of the quarry. The quarry has made a huge effort to screen the operation, with a large earth bund formed with imported material. As there is no stripping material on the site, the rock starts at ground level with no weathering of rock near the surface. An interesting innovation in the sand plant is the use of an air separator, basically a large fan inside a large cyclone. 
A minus 5mm sand is added to the top of the cyclone, the fan sets up a flow in the tank, the 75um is separated out as an agg-lime and the remaining sand is used for concrete aggregate. The fan speed can be controlled to give the required end product and the feed material can have up to five per cent moisture. In Australia, quarry operations mostly do not wash any chips or manufactured sand because of the lack of water in most locations, and their customers are accepting of the end products.
The quarry is a quartzite rock located within a national park, has a creek running through the centre and sometimes lost walkers and rock fossickers end up wandering into the quarry, providing some challenges for my guide, quarry manager Mike Harvey. 
{{image6-a:r-w:200}}The quarry also has to meet visual criteria from the city of Adelaide and close neighbours. Rock is drilled and blasted by quarry staff and loaded onto a truck with a WA600 wheel loader. The quarry has operated for more than 70 years and has about 15 years of reserves left. It can produce about 450,000 tonnes per year. This is quite an achievement with an ageing plant perched on a side of the hill. The screen house is new, as the old one burnt down some years ago. The new shed was built over the existing product bins. Again, from a distance, the quarry can be seen but once you get close, the quarry is well screened by the natural topography.
When leaving the Franklin Central Apartments in Adelaide at 5am on Sunday morning, I must have still been half asleep as I left all my travel documents in the hotel room. I only realised just before boarding the plane to Hobart, via Sydney. This made life interesting as I knew I had a car booked but all other info was still sitting in my room in Adelaide! The staff at the Franklin Central Apartments were fortunately able to give me all I needed to know over the phone. Phew!
Hobart has three hard rock quarries within 25km of the CBD. Three different operators own them. The reserve of all three quarries is beyond 100 years. The population of Hobart is about 230,000, with a market size of about two million tonnes per year. The major problem is permits for quarrying are only issued for a maximum of 30 years.
Lindisfarne is a dolerite quarry. Dolerite is not commonly quarried in the world as it has limited outcrops. Due to the rock being quarried from a pit, this was the only quarry that used an excavator to load trucks; a PC600-8 loaded Cat 773 dumpers. In the near future, the quarry will expand back into the hill. An innovative method will be the use of a downhill conveyor. This may not be that unusual but the quarry is going to use the conveyor to produce electricity to power part of the crushing plant. 
Lindisfarne?s current production is 200,000 tonnes through a 42? x 30? jaw, a Jaques C50 and a Canica for fines and shape. The quarry has an older plant but one of the best set-up control rooms I have seen, with excellent views of all crushers, screens and conveyors. There is a concrete plant on-site, along with an asphalt plant run by Downer EDI. The plant produced very little fugitive dust, unlike many of the other plants I visited. (Most would not survive in New Zealand, as regional councils would be obliged to shut them down). Again the quarry originally had a creek running through the middle. Aggregate is loaded out with a WA420 wheel loader. Frank Carpenter, Hanson?s quarry manager, co-ordinated my trip in Hobart. I am very grateful to him and his team for their hospitality. 
This quarry reminded me of Blackhead Quarry in Dunedin (where I work), as the rock in the quarry ? a black basalt – is almost identical. There is a concrete and asphalt plant on-site. Rock is blasted and loaded by a wheel loader onto trucks feeding a 30? x 42? jaw, secondary and tertiary cones and an Auspactor (similar to the Barmac, Canica) with an open rotor. Like many operations, Bridgewater Quarry has a pug mill for road base. The pug mill has a stacker conveyor that enables great flexibility for customers? needs. They just move the conveyor, change recipe and can have a ?to spec? product in a stockpile within half an hour. The control room is the only one I have been in that has very retro shagpile carpet on the walls! It was obviously built in the 1970s. My guide was Mike Pilcher, Boral?s South Tasmania area manager.
{{image8-a:r-w:200}}John Sherburd, Hazell Bros business manager, was my tour guide. He is a very motivated, passionate man. Hazell Bros is a local family owned company, based in Tassie but which also operates in Victoria. Hobart Bluestone Industries also quarries a dolerite rock, a great quality rock with very little stripping and minimal weathering profile. The plant is now four years old with PLC automation. A contractor carried out blasting and the rock was loaded by a WA600 on to 35-tonne Komatsu dumpers. The quarry is located 15km from the CBD. Although it has a massive rock reserve, Hazell Bros also carries out the recycling of construction waste and crushes glass to minus 4mm as an additive to basecourse and sand substitute. Like New Zealand, there are limits on the percentage of crushed glass permitted in aggregate.
I am very grateful to a number of people who made the trip the experience of a lifetime, including my wife Diane for allowing me to go away and holding the fort while I was gone. It?s not that easy when you have a young family and you have to go on a study tour to Australia. I am also grateful to my employer, Blackhead Quarries Ltd, which supported the study tour and also backs my role as Institute of Quarrying NZ President, and the Institute, which makes these awards available to its members. 
A special thanks also to Rick Johnson and Rocktec for providing the Innovation Award of $5000. This is a significant sum of money that comes straight off the company?s bottom line. Finally, my thanks to the many quarrymen who took time out of their busy schedules to show a Kiwi how they crush rocks. ?
Gavin Hartley is the President of the Institute of Quarrying New Zealand and a director of Blackhead Quarries Ltd, Dunedin, New Zealand. He will be presenting at the IQA annual conference on Thursday 19 September 2013.

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