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Crushing Circuit Chutes and Screens - Wear Material (29 replies and 1 comment)
Hi, sometimes wear very much relates to the chute design, liner arrangements and not just the wear material. +600 brinell chrome steel makes for great wear liners.
Do you have pictures/photos of your chutes/liners you can share?
For chutes for both impact and wear resistant we may consider high manganese steel liners (12-14% Mn) or design of suitable rock boxes to minimise wear. For screen deck, high carbon steel or suitable wear resistant polymer may be used. It seems they are using plain MS plate which may not last long.
Thank Dimay,
this looks like a "naked" unlined chute. Is that so? What are you using for inside/inner lining? Anything?
Normally, you'll bolt some wear surface on the inside just like you would in a grinding mill.
See idea in image here.
Hi Dimay, try using a hardox plate material on your chute particularly where wearing rate is high. Also, re-design it as Bob mentioned like consider the material trajectory and strategically placing a dead box to act as an impact plate. This will absorb and control the velocity of discharge and minimize the abrasive impact wearing.
Thanks Bob and tungsten644 for you important advice it helps me a lot.
yes it is naked we are not using any liner. we have tried once to line it with belt but we didn't get enough to do it routinely (conveyor belt rubber ).
Can you give me any lining alternatives.
Conveyor will not last long on direct impact zones. You can use new materials or old mill liners. Look at https://redesign.911metallurgist.com/blog/sag-mill-feed-chute-design-long-life-wear-resistant for some new ideas.
Hi Dimay, what about your screens? Do you have photos of what you are using now? Why must you use steel screens? What size/shape openings are you using?
Please see the attached photos.
20*60mm for double deck screen closed circuit with tertiary crusher
2*2mm ball mill discharge oversize back to mill and under-size feed to cyclone
thanks. the screen on the right is your tertiary crusher top or bottom deck?
+ explain this ball mill 2x2 discharge setup for me please. Do you have photos at a distance to show me (and Bob) the arrangement?
What is your tonnage? Ball Mill size? HP? The more details you give, the more we can help you + sometimes, in unexpected ways...
Yes the right one is for the tertiary crusher and it is the bottom deck
Ball Mill type KWI 2.1MWatt
Size 4.5 (diameter) x 6.3
Discharge type overflow
Tonnage 2000 ton/day
Mill product p80 75microns
The ball mill product goes to vibrating linear screen mesh size of 2*2mm.
See the attached flow diagram.
interesting...
what is your ball diameter?
did you ever do a screen analysis on ball mill discharge (screen feed)?
your bottom deck = 20*60mm and that goes to your ball mill feed?
what is the power draw on you mill normally?
Hi Dimay,
As many have listed above there may be a number of different ways to assist with your wear problem. This may include whole chute design or perhaps a range of wear plates.
Please see some photos of different solutions at the links below.
http://www.tegaindustries.com/product_details.php?pid=7&catid=10
http://www.tegaindustries.com/product_details.php?pid=5&catid=10
http://www.tegaindustries.com/product_details.php?pid=4&catid=10
http://www.tegaindustries.com/product_details.php?pid=6&catid=10
Tega also manufacture complete chute units.
Thanks JIM Brodie and Bill Fraser
ball mill diameter=4.5m and length 6.3m
15.3 revolution/min
ball mill discharge size analysis average = 60% pass 75 micron
cyclone over flow size analysis average= 77% pass 75micron
power draw currently we are not collecting any data but i am working on it.
what is your ball diameter (the ball size)?
your bottom deck = 20*60mm ...does that go to your ball mill feed? What is your ball mill feed P80?
+ is this an underground or open pit mine?
Hi Dimay,
at 60% pass 75 micron, why do you even screen the ball mill discharge? Why not go direct to cyclone? That is what is common...
if you insist on screening your ball mill discharge, see Polydeck Vector Slot Technology (VST) Panel
Dimay, where did your flowsheet go?
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Dimay,
power draw currently we are not collecting any data: you have no idea what you are drawing now?
If you are really feeding your ball mill 10 mm F80, your 100 mm ball seems on the large side of the 80 mm calculated by https://redesign.911metallurgist.com/blog/top-ball-size-grinding-media-calculator particularly if you are trying t o get to 75um.
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with wear liners and screen media , over the years there has been a lot of smoke and mirrors, 🙂
I have designed liners for Chutes, hoppers bunkers , grinding mills - cast steel, rubber composites etc and was involved with EVERY initial Polymet / steel capped lifter design here in Australia and in India - as well as the first mill modular discharge systems
I work with various wear liner materials and each has their own niche - don't let anyone ever tell you otherwise - a seller /manufacturer will push what they make and or can source nothing more , EVEN IF IT IS THE WRONG material for the application. read these articles of mine
1 on screening - https://www.linkedin.com/pulse/getting-your-cross-tension-screens-operating-peak-stewart-fernandez?trk=prof-post
https://www.linkedin.com/pulse/screening-guide-stewart-fernandez?trk=mp-reader-card
2 the interesting one on the choice of and the use of materials in various applications
If you want the charts - contact me , they are free - lets burst the myth and B@##%71^ , ? on wear materials and definitely read this to understand what wear reliability is all about - https://www.linkedin.com/pulse/my-knowledge-wear-reliability-improvement-increased-plant-fernandez?trk=mp-reader-card
the selection of material on wear liners
Our crushing circuit contains primary crusher jaw , secondary cone crusher and tertiary cone crusher in which closed circuit with a double deck screen. the ore is quartz vein with average of Bond RWI 17.5khr/t and Bond BWI 16.8 kwhr/t.
The chutes are made by our welding team but they don't have much life i want your help for selecting correct metal for constructing the chutes and good quality of steel screen.