MINERAL SEPARATION
engineers who have spent years working with similar applications and setups and who have had the opportunity to observe why some cyclone applications succeed and why other cyclone applications struggle .”
One example of this comes from Tüprag Metal Madencilik , a Turkeybased subsidiary of Eldorado Gold Corp . At this operation , the process team were not happy with the overall performance of the existing hydrocyclone cluster of four 400 mm hydrocyclones . The cluster required frequent maintenance that resulted in a four-hour production downtime period every three months . The equipment also did not consistently achieve the desired P80 cut point on the overflow due to fluctuating cyclone feed flow rate and pressures .
The Cavex cyclones team worked closely with Tüprag ’ s design engineers to replace the existing competitor cyclones and develop a solution to increase the classification throughput , efficiency and wear life performance , all while fitting into the existing footprint . This was achieved by incorporating a larger quantity of smaller hydrocyclones to fit into the available footprint . The solution included a cluster of eight Cavex 250CVX hydrocyclones , designed to fit without modification . Weir Minerals manufactured the Cavex hydrocyclones , lined the underflow tanks with Linatex ® premium rubber and assembled the complete cluster . The cluster was installed and commissioned within two days .
At the start of the project , the incumbent competitor hydrocyclone cluster ’ s overflow mass flow rate was approximately 50 t / h . The Cavex 250CVX eight-cyclone cluster , on the other hand , produces up to 77 t / h , with a circulating load reduction from 342 % to 245 %. Ceramic spigot liners further improved wear life by 75 %. Tüprag now consumes one set of spare parts per year , compared with previously replacing the liners every 2-3 months , Maquera Coyla said .
Mill operators also need to plan for changes in operating conditions when selecting cyclones , choosing a solution that can accommodate both the optimal and sub-optimal conditions likely encountered during the cyclone ’ s lifetime . For example , factors such as ore hardness , particle segregation , varying ore specific gravity or clay content influencing the pulp ’ s viscosity will all affect the operation of equipment . These factors should be anticipated and planned for if considered a probable risk .
One example of the Cavex cyclone improving the hydrocyclone process comes from Highland Valley Copper ( HVC ) Mine in British Columbia , Canada . Operated by Teck Resources Ltd , the mine produces between 115,000 t / y and 120,000 t / y of copper .
Operators at HVC wanted to upgrade classification in all the grinding circuits by replacing the incumbent hydrocyclones , which were tangentially fed , to improve the efficiency of the hydrocyclone classification , increase unit capacity and lower the maintenance costs .
Prior to working with Weir Minerals , the site tested smaller 660 mm diameter hydrocyclones from various manufacturers over time without success . Together with the Cavex cyclone experts , the HVC Mill Technical Development team began to develop and test an 800 mm diameter hydrocyclone that combined a Cavex 800CVX hydrocyclone head and body with the cone geometry of the 762 mm diameter hydrocyclone . Using the existing cone angle geometry allowed the larger Cavex 800CVX hydrocyclone to fit into the existing hydrocyclone cluster and building infrastructure . HVC sent a 762 mm hydrocyclone to Weir Minerals for a head retrofit study . The hydrocyclone was scanned and modelled in three dimensions . Simulations concluded that the classification performance of the Cavex 800CVX hydrocyclone would meet HVC ’ s classification targets , and three Cavex 800CVX hydrocyclones were designed and installed for a full-scale trial .
Results have shown the Cavex 800CVX hydrocyclones required less maintenance and were more tolerant to process upsets than the incumbent 762 mm hydrocyclones , according to Maquera Coyla . Additionally , the Cavex hydrocyclones handled approximately twice the capacity and the rubber
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