Grinding & Classification Circuits

Grinding & Classification Circuits

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Wearing out cyclone underflow pump liner (8 replies and 2 comments)

j
JOHN
8 years ago
JOHN 8 years ago

Hello guys. I really need your expertise advice and ideas. 

The plant I work for is a gold processing plant. They have a real problem with the pumps from cyclone underflow to ball mill. The mill section comprises a ball mill, screen and cyclone. I have done a water balance for a couple of times.however, since the last seven days, the screen was damaged and the density( mass percent) of the underflow of the cyclone increased by about 15%, which is so weird. At the mean time the rubber liner of the underflow cyclone pumps got torn out. I thought, because the screen is not working properly, almost the size separation is done mainly by cyclone. And Since Grinding is achieved through ball mill only, we expect the size of the discharge is a coarser than grinding with both ball and sag mill. What I think is, because the screen is damaged, the size of the cyclone underflow may be coarse enough to wear out the rubber of the pump. So what do you say about my idea? If not what do you think the problem is?

   Here is the attached flow chart 

Paul Morrow
8 years ago
Paul Morrow 8 years ago

Hi John,

Underflow of the cyclone increased by about 15% to what% ?

Really, you pump your cyclone underflow to the ball mill?

I do not understand your flowchart...

j
JOHN
8 years ago

The mass percent is increased from 65% to 80% for the underflow pump. And the underflow of the cyclone goes to the ball mill which is the circulating load (sand).
Thanks

Paul Morrow
8 years ago
Paul Morrow 8 years ago

yes, but are you really pumping that underflow?

j
JOHN
8 years ago

Sorry paul, but What is the problem? The cyclone underflow is going to the ball mill for sure. But can you please explain to me why you sound perplexed?

(unknown)
8 years ago
(unknown) 8 years ago
1 like by Arnmax

Hi John,

the size of the cyclone underflow may be coarse enough to wear out the rubber of the pump

Absolutely. But why do you have to pump that? You can't gravity it?

Paul Morrow
8 years ago
Paul Morrow 8 years ago
1 like by Arnmax

John, what is odd is not where the U/F goes to, it is how it gets there. Am curious as to your plant layout. 

Common practice is to pump the cyclone feed but to allow the U/F to flow by gravity to the ball mill. No pump = no wear.

PS: 80% underflow solids is... good!

j
JOHN
8 years ago
JOHN 8 years ago
  • Thanks very much paul and tony. Really appreciate your ideas.I would be happy to tell you the details, but it's against the regulation of the company. What I want to know is whether the coarse particles has an effect on the rubber.thanks.you gave me what I need.
(unknown)
8 years ago
(unknown) 8 years ago

Hi John,

yes coarse particles have an effect on the rubber. They will eat it up.

j
firebird
8 years ago
firebird 8 years ago
1 like by David

Hello john.

What tony and pawl said are correct. Your liner could be dead with coarse sized minerals, however you better be specified with the rock properties. High resistant minerals could have an enormous effect on the liners. But it still minded me where ur cyclone is placed. Gravity is gift of nature in processing.better u sleep over it.anyhow, ya it kills it.

J
johnclark
8 years ago
johnclark 8 years ago

Hi John. Until you get things running back to normal, how about trying more steel balls in the ball mill. Could you get your hands on a more resistant pump liner quickly. Can you possibly reconfigure the location of the cyclone, so that the cyclone underflow drops into the ball mill feed (as suggested by other comments)? Has the ore become harder recently? Is the pump on the small size for the cyclone underflow flow rate and running at the upper RPM - rather than having a larger pump running at lower RPM?

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