Modern Quarrying October-November 2017

ON THE COVER

most profitable output, minimise wear and avoid downtime.” He says that one of the critical factors is achieving the optimum closed-side setting (CSS) for the desired output. The key is to balance yield with production profit; certain fractions are always more valuable. “So now the CSS on the jaw is running at 177 and recently we ran it at 240 CSS,” Ackerman says.“We had a few other issues because the feeder also became a prob- lem together with the transfer points. We have now brought it back to 175 where it is supposed to be and our tonnage is 100 t/hour more than previously. “There are knock-on upgrades being carried out in the rest of the plant. We know that we can run at 300 mm easily. Sizing wise, we are getting to where we want to be and this machine can really crush. “My personal feeling is that it is a bit oversized but the capacity is there,” Ackerman confirms, “and if we want to increase our crushing capacity, we can. The beauty of this machine is that it doesn’t have to be kept full, it can take surges and can handle fluctuations because of its design.” He says the material produced is excellent. “We can see the difference with the naked eye. Another benefit is the ASRi (Automated Setting Regulation) system, which allows us to set our CSS easily and to keep it constant.” Taking this further, Taylor says that while the basic machinery used in rock processing has remained fundamentally unchanged for many years, the industry has nevertheless become considerably more high-tech. “You may not be able to

crush rock with your PC, but you can cer- tainly use advanced technology to ensure that crushers are performing optimally, that your product quality is high and con- sistent, and that machinery downtime is minimised. “The ‘i’ in ASRi means intelligent and the reason behind this is that it not only helps you to monitor operations, but over time enables you to become so familiar with your crushing equipment that you can truly optimise its usage while protect- ing it from damage. “Regardless of whether a quarry is a simple one-crusher operation, or a larger, more complex plant, the Sandvik ASRi is guaranteed to improve results. One can decide on which system to use, how fre- quently and at what capacity, all of which makes the system not only intelligent but very flexible. “The other benefit of the ASRi is that you can set your CSS and it’ll maintain it for you. As your lining wears, it automat- ically compensates and keeps it there, so the material doesn’t end up as oversize on your stockpile. It’s a constant product all the time. For example, you can also set it to run on a 13 mm for an hour and then to run for a 19 mm product. It’s like utilising the perfect operator,” he says. Getting back to the machine itself, Ackerman says the industry is used to the old generation crushers, “but once they understand the CS440 and work with it, it is actually a very simple crusher to use. “We are so happy with the CS440 machine that we’ve brought a CH440 back here from Mozambique. It’s an old Sandvik has a very strong relationship with quarry owners, with trust being the key. Photograph shows technical sales and support specialist Adam Taylor on the left with Lyttleton Dolomite quarry manager Piet Ackerman.

Sandvik Mining and Rock Technology recently supplied, installed and commissioned a CS440 secondary stage crusher. This machine is suitable for any high-capacity secondary crushing application.

2007 model and needs a bit of work, but we’re going to use it in a tertiary crusher application. It is also a bit overdesigned for that, but it has the capacity.” Taylor says that the CH looks to be more or less the same size as the CS unit. “The bottom shell is identical, but the top and the shaft differ. It uses the same 220 kW motor but in terms of capacity, because it is a tertiary machine, the mate- rial remains in the chamber a lot longer than the S machine. It will produce a finer material and give shape, etc.” Talking about the mine, Ackerman says it is doing very well. “We went through a dip when Highveld Steel closed down, as that was about 35% of our busi- ness. However, we are focusing on the aggregate market and we have seen some good growth in this sector. “The industry is competitive and we are trying to keep our prices stable with stock on the floor. We have cut down our product range from 14 to six products, which is why we needed the new crush- ing technology.” Ackerman says the mine is doing well. “Since April, the machine has provided comfort in providing more than sufficient capacity to ensure stock on the ground. I am delighted at the efficiency of the new machine. The crusher is creating a lot of fines which is essential for producing the sands we are manufacturing. It is making a huge difference to our production.” Brief history of Lyttelton Dolomite The mine was established in 1938 by Amcor for the purpose of supplying

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MODERN QUARRYING

October - November 2017