Modern Quarrying Q2 2019

for replacement parts, a significant improvement from the 120 hours. The 400CVX10 hydrocyclone has proved to be more efficient than the conventional cyclone. “We used to replace pump liners regularly, and since we installed the WBH 100 pump, we no longer have pumps on the critical maintenance list. Pump problems are a thing of the past. The Cavex 400CVX10 hydrocyclone increased the mass pull to the underflow, which resulted in increased production and reduced slimes to the tailings dam. Using this new technology is paying dividends,” says Carl Crous, owner of CNC Crushers. Following the crusher upgrade, a competitor’s installed primary classification and tertiary screens were replaced with Trio ® TIO5162 (5’ x 16’ double deck inclined screens, and the final product screen was replaced by a Trio ® 4102 (4’ x 10’ double deck) inclined screen. Product range from Shaft 5 plant comprises 6,7 mm; 9,5 mm; 13 mm; and 19 mm stone, as well washed crusher sand and crusher dust. Shaft 4 Following the success of the plant upgrade at Shaft 5, CNC Crushers decided to upgrade its existing plant at Shaft 4. The plant was running old model crushers and screens with outdated technology. The main problems encountered included high wear on crusher liners, high oil con- sumption and unplanned downtime due to persistent breakdowns. The Weir Minerals team proposed replacing the old technology 4.25 ft secondary cone crusher with new technology Trio ® TC51S standard hydraulic cone crusher. The tertiary cone crusher was also changed from an old technology 3 ft to a new technology Trio ® TC36SH standard hydraulic cone crusher. With uptime in mind, the new technology Trio ® cone crushers feature a hydraulically adjusted Closed Side Setting (CSS), allowing for quick adjustment of the setting; and a hydraulic tramp relief which protects the machine by preventing uncrushable material from entering the crusher and causing damage. Willie Crous tells Modern Quarrying that with the previous old technology

ON THE COVER

Following the plant upgrade at Shaft 5, a 45% increase in plant throughput was realised, owing to reduced downtime and improved crusher performance.

Using Weir Minerals Africa’s new technology equipment has ensured greater equipment availability and utilisation for CNC Crushers.

problems and plant downtime. CNC Crushers required a solution from Weir Minerals Africa that would utilise the existing footprint and infrastructure. The first machine to be installed by Weir Minerals Africa was the Trio ® TC51S cone crusher, which replaced an old technology secondary cone crusher. Lapidoth says there was an immediate increase in uptime and reduced maintenance costs, which prompted the client to purchase a Trio ® TC36SH tertiary cone crusher. “The products quickly increased plant availability and production, while meeting the criteria of utilising CNC Crushers’ existing footprint and infrastructure at Shaft 5,” says Lapidoth. Key results from these interventions include a 45% increase in plant throughput owing to reduced downtime and improved crusher performance; reduced closed side setting adjustment time from 90 minutes to five minutes as Trio ® cone crushers incorporate multiple hydraulic cylinder clamping and adjustment; and quick and simple crusher maintenance. Additionally, Trio ® cone crushers have a larger socket assembly giving full support under both extreme and light load conditions, thus providing a longer crusher service life. Another key challenge on site was the high wear on the existing conventional cyclone and the old Envirotech ® pump – which called for replacement of liners every 120 hours of operation. “The cost here was twofold – frequent replacement of liners cost a lot of money, while the cost of downtime related to the replacement process was just too much to bear for the client,” explains Lapidoth. “The brief from the client was to increase solids to the cyclone underflow, and increase wear life on the cyclone feed pump.” To improve the process, Weir Minerals Africa provided a Warman ® WBH 100 slurry pump and a Cavex ® 400CVX10 hydrocyclone to CNC Crushers. After 1 900 operating hours, the WBH ® 100 slurry pump was still running without any need

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MODERN QUARRYING QUARTER 2 - 2019