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Crushing Circuit Chutes and Screens - Wear Material (29 replies and 1 comment)

New Era
3 months ago
New Era 3 months ago

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.

Bob Mathias
3 months ago
Bob Mathias 3 months ago

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?

dk
3 months ago
dk 3 months ago
1 like by New Era

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.

New Era
3 months ago
New Era 3 months ago

Please see the attached pictures

img_20160918_190135
https://www.911metallurgist.com/wp-content/uploads/2016/09/IMG_20160918_190135.jpg
img_20160918_190120
https://www.911metallurgist.com/wp-content/uploads/2016/09/IMG_20160918_190120.jpg
Bob Mathias
3 months ago
Bob Mathias 3 months ago

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.

crusher-chute-liners
https://www.911metallurgist.com/wp-content/uploads/2016/09/crusher-chute-liners.png
tungsten644
3 months ago
tungsten644 3 months ago
1 like by David

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.

New Era
3 months ago
New Era 3 months ago
1 like by Aminpro

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.

Bob Mathias
3 months ago
Bob Mathias 3 months ago

Conveyor will not last long on direct impact zones. You can use new materials or old mill liners. Look at https://www.911metallurgist.com/blog/sag-mill-feed-chute-design-long-life-wear-resistant for some new ideas.

New Era
3 months ago
New Era 3 months ago

Thanks Bob I really appreciate for your advise 

 

Bill Fraser
3 months ago
Bill Fraser 3 months ago

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?

New Era
3 months ago
New Era 3 months ago

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

img_20160919_050514
https://www.911metallurgist.com/wp-content/uploads/2016/09/IMG_20160919_050514.jpg
img_20160919_050249
https://www.911metallurgist.com/wp-content/uploads/2016/09/IMG_20160919_050249.jpg
Bill Fraser
3 months ago
Bill Fraser 3 months ago

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...

New Era
2 months ago
New Era 2 months ago

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.

Bill Fraser
2 months ago
Bill Fraser 2 months ago

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?

Jim Brodie
2 months ago
Jim Brodie 2 months ago

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.

New Era
2 months ago
New Era 2 months ago

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.

Bill Fraser
2 months ago
Bill Fraser 2 months ago

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?

MillMan
2 months ago
MillMan 2 months ago
1 like by New Era

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...

New Era
2 months ago

originally our grind size was 106 micron we was running gravity system but now we terminated it. This why the design includes screening.

Paul Morrow
2 months ago
Paul Morrow 2 months ago
1 like by New Era

if you insist on screening your ball mill discharge, see Polydeck Vector Slot Technology (VST) Panel 

https://youtu.be/M-snA78zfho?t=12s

New Era
2 months ago
New Era 2 months ago

Thanks Bill , MillMan ,Paul

It is open pit mine 

The bottom deck screen under size product is ball mill feed

Ball mill feed p80 10mm

Ball size 100mm

 

David
2 months ago
David 2 months ago

Dimay, where did your flowsheet go?

MillMan
2 months ago
MillMan 2 months ago
2 likes by Bill Fraser and David

You should simply bypass that gravity screen you no longer use. Why not?  Just remove the screen panels and let the slurry pass thru.

Bill Fraser
2 months ago
Bill Fraser 2 months ago
1 like by David

DIMAY,

A Ball mill feed P80 10 mm after passing a 20*60 mm screen? Something does not look right...

Your P80 should be more like +20mm I'd say. Can you confirm this? I am looking for the screen undersize P80=?

New Era
2 months ago
New Era 2 months ago
1 like by David

Sorry David 

Here is the flow sheet

grinding-2
https://www.911metallurgist.com/wp-content/uploads/2016/09/GRINDING-2.jpg
New Era
2 months ago
New Era 2 months ago

Sorry Bill
the correct size is 12*20mm

David
2 months ago
David 2 months ago

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://www.911metallurgist.com/blog/top-ball-size-grinding-media-calculator particularly if you are trying t o get to 75um.

Bill Fraser
2 months ago
Bill Fraser 2 months ago

If you can successfully test what MillMan said, you'll save a screen and a pump (you can gravity flow the ball mill discharge direct to cyclone feed) afterwards.

New Era
2 months ago
New Era 2 months ago

Thanks Bill and David

Stewart_fernandez
4 weeks ago
Stewart_fernandez 4 weeks ago

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

https://www.linkedin.com/pulse/easy-selection-appropriate-wear-liner-materials-stewart-fernandez?trk=mp-reader-card

 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

guide-to-liner-selection-based-on-material-size-and-angle-of-impact
https://www.911metallurgist.com/wp-content/uploads/2016/11/guide-to-liner-selection-based-on-Material-size-and-angle-of-Impact.jpg
Stewart_fernandez
4 weeks ago
Stewart_fernandez 4 weeks ago

the selection of material on wear liners

guide-to-liner-material-options-at-various-stages-in-a-plant
https://www.911metallurgist.com/wp-content/uploads/2016/11/guide-to-liner-Material-options-at-various-stages-in-a-plant.jpg

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