SEPARATION & CLASSIFICATION
Multotec ’ s own people and the training that it offers to clients . “ When you know a product so well , you are able to provide presentations at a very detailed level - not only sales focused , but giving an in-depth understanding alongside taking complex processes and explaining them in a straightforward way . This is across operations , maintenance and metallurgical staff . We also train engineering houses and offer them ongoing guidance .”
Customisation for particular markets
What about specialised solutions for certain application types , especially in southern Africa ? “ One of them is when you have open circuit milling where you need to have a dewatering cyclone configuration of what are called separator or stacker cyclones ,” Bekker said . “ It dewaters feed from a flotation circuit to the right density before it goes to the mill . Another example would be a guard cyclone , which goes before the thickener to take some load off the thickener and prevent coarse material entering which could create a blockage . In the platinum and UG2 circuits in South Africa and Zimbabwe , you have a chrome-silica split where you separate the PGM bearing material and the chrome rich material . This is one area where our flat bottom cyclones are used . Then cyclones in ultra-fine grinding circuits using smaller diameter milling cyclones .”
Finally , Australia has also become an important market for Multotec cyclones . Bekker explained : “ We first made a big impact in Australia with cyclones on the east coast in coal specifically for dense media separation . Then we expanded to the west coast to hard rock mines . Our offices there have service contracts with individual operations at a level where we manage and maintain their cyclones for them including maintaining performance levels . These service contracts in some cases also extend to equipment from other suppliers . The growth of the lithium industry there is also opening up new business for us .” IM
Metso Outotec ’ s MHC™ hydrocylones making their mark
Metso Outotec is a relatively new player in hydrocyclones but is gaining momentum fast . IM caught up with Ben Klein , Product Group Manager , Classification . The MHC™ hydrocyclone was developed all in-house and completed in 2014 , followed by validation work in 2015 and then a global launch in 2016 . So what did it bring to an already competitive market ?
“ We wanted to see how we could improve hydrocyclone operational and maintenance performance , and particularly reliability . When you look at the MHC™ hydrocyclone compared to other designs , the big difference is in the conical section , which is one piece and polyurethane . Being one piece makes it easier to replace , with a set of bolts at the top attached to the head assembly and then at the bottom bolts attached to the apex or the spigot . So you can swap out the whole cone when you need to .”
Klein also said that the polyurethane has produced some really good wear results – as good as natural rubber . “ You get reduced maintenance time , but at the same time you are getting about the same wear life as rubber . Of course , it ’ s going to be a little bit different for each application . But in relative terms , reliability is increased , and downtime decreased .” For some very high wear applications there are also have options for ceramic at the bottom of the hydrocyclone – in the spigot and in the bottom third of the cone .
In terms of process performance , MHC™ has a slightly different geometry throughout the hydrocyclone . “ In the head housing , our scrolled involute design is a little bit different – the feed slurry is introduced into the hydrocyclone very smoothly , resulting in reduced wear in the head assembly , but also improved classification . We also have a unique shape down through the cone section for improved classification efficiency . Also , for the same overflow product , we ’ re able to operate the cyclone at a reduced pump pressure for the same capacity meaning you can reduce the pump speed and get power savings . Conversely , you can keep the pump speed the same , which means you ' re pushing more capacity through the hydrocyclone , conservatively 10 %, but with the same sharp separation curve .”
Currently Metso Outotec is concentrating on the core mill grinding circuit cyclone market but is also quoting for dewatering , desliming , and tailings applications and has a new reference for that in Sweden which has already been very successful .
On the market itself , Klein stated : “ It took a few years to finally break into the market , but we ' ve had a lot of success in the last two and a half years , with many of the projects now being installed and commissioned . Mainly these are in copper , iron ore and aggregates ; this includes a very large copper project in South America and also several examples in North America , Europe , India , Central Asia and Australia . So , we are seeing a lot of interest globally .”
The MHC™ portfolio has seven sizes , from the MHC™ 100 , a 4 in cyclone , all the way up to the MHC™
800 , which is used for primary for secondary copper mill grinding circuits . For a Canadian copper mine , Metso Outotec also recently installed its first cluster with inclined cyclones to help save space in a smaller footprint .
24 International Mining | MAY 2023