SEPARATION & CLASSIFICATION
Cavex hydrocyclone experts delivered a solution that allows us not only to improve the recovery of the final product and reduce the loss of a valuable component with tailings , but also to increase our capacity to process raw ore . The efficiency of our entire copper plant benefitted from this upgrade ,” he said .
As a result of the successful trial , the New Cerovo placed an order for 12 single units to be installed in the existing cluster and committed to replace all installed cyclones on the mill cluster with Cavex ® hydrocylones .
Weir Minerals Cavex ® 500CVX hydrocyclones at New Cerovo
New Cerovo sought Weir Minerals ’ equipment and process expertise to assist it in making its classification process more efficient and sustainable . The incumbent mill circuit installation comprised a cluster of 12 conventional 500mm hydrocyclones ( 6 operating ), supplied by a local competitor . The incumbent cyclones ’ cut point was too coarse and their inefficiency was resulting in a low mass split to the overflow , which ultimately meant the copper recovery was much lower than desired .
Weir Minerals proposed replacing the inefficient incumbent cyclones with Cavex ® 500CVX hydrocyclones in an effort to increase the recovery of fines . The laminar spiral inlet geometry design provides a natural flow path into the Cavex ® hydrocyclone . Its unique shape – it doesn ’ t have any sharp edges , shelves or square corners – allows the feed stream to blend smoothly with rotating slurry inside the chamber .
In Cavex ® hydrocyclones , a controlled feed stream blends progressively and smoothly , reducing turbulence throughout the hydrocyclone . Since there is less resistance to slurry flow , the hydraulic capacity is significantly increased .
As part of the initial trial , six Cavex ® 500CVX hydrocyclones were installed in the existing cluster body , replacing the incumbent hydrocyclones . The New Cerovo mine ran an extensive eight-month sampling campaign and calculated that the new Cavex ® hydrocyclones allowed the site to achieve a 13.16 % increase in throughput and 7.62 % increase in minus 75 µ m material recovery .
This improvement resulted in a monthly additional revenue of US $ 600,000 , or US $ 7,200,000 per annum based on the market value of copper at the time of the trial ’ s conclusion . Based on these figures , the return on investment on the Cavex ® hydrocyclones was just 6 days .
The project highlights the obvious benefits when miners and OEMs work together , Dragan Peric , Zijin Mining Serbia ’ s New Cerovo Plant Manager said . “ Our primary focus for the trial was achieving a finer cut point for the cyclones while increasing the content of minus 75μm in the cyclone overflow . The Weir Minerals team of
Ernest Bekker , Multotec Product Specialist , Hydrocyclones
Multotec ’ s cyclone circuitry
IM also had the chance to talk in some detail about hydrocyclone applications , performance and pitfalls with Ernst Bekker , Multotec Product Specialist , Cyclones , which provided a unique insight into this market . Cyclone use in mining includes a very wide range of duties – for both classification and dense media separation cyclones . In terms of classification , you are really looking to distribute material to two subsequent processing stages – the overflow fines , for example , to flotation and the coarser underflow to spirals or up-current classifiers . When looking at milling circuit cyclones specifically , you have primary , secondary , tertiary and sometimes quaternary milling applications , and in each case , the cyclones can be used slightly differently , but with the main aim to remove coarse for regrinding . Then you have de-sliming applications for cyclones with the aim of removing slimes before the next process , such as before flotation , where in some cases , slimes can act as an unwanted flotation reagent consumer , which does not add value to the recovery process and can also lead to increased final product moisture contents .
Slimes can also be detrimental to gravity applications like spirals where they can hamper
20 International Mining | MAY 2023