Dewatering: Thickening, Filtering, CCD, Water Treatment & Tailings Disposal

Dewatering: Thickening, Filtering, CCD, Water Treatment & Tailings Disposal

  • To participate in the 911Metallurgist Forums, be sure to JOIN & LOGIN
  • Use Add New Topic to ask a New Question/Discussion about Thickening, Filtering or Tailings and Water.
  • OR Select a Topic that Interests you.
  • Use Add Reply = to Reply/Participate in a Topic/Discussion (most frequent).
    Using Add Reply allows you to Attach Images or PDF files and provide a more complete input.
  • Use Add Comment = to comment on someone else’s Reply in an already active Topic/Discussion.

Cyclone Sizing (3 replies and 3 comments)

B
Boyd
7 years ago
Boyd 7 years ago

Hello everyone,

i need help with the size of cyclone i can install to act as a bypass to the overloaded concentrate thickener and avoid dirt overflow. Basicaly i want to split the feed to thickener in 40% to 60% or what ever percentage of feed to go to the underflow at 65% solids and this will be ready to feed the filter, while the cyclone overflow goes to the thickener to be thickened and attain a density of 65% solids before filtration. The following are the parameters:

Cyclone Feed; 15% to 35% solids, 35m3/h flowrate, 80% passing 45um.

Under Flow; 65% solids.

A
adrianh
7 years ago
adrianh 7 years ago
Like

https://www.911metallurgist.com/blog/hydrocyclone-design-equations-and-sizing-parameters-calculations

B
Boyd
7 years ago

Hi Adrianh, i really appreciate you so much for sending this useful link

R
Romain CADENAT
7 years ago
Romain CADENAT 7 years ago
Like

Hi Boyd

Your feed in thin (80%<45µm) so you should use small hydrocyclone. Maybe a cluster of 2 or 3 small HC. 

However I have one comment: you say that the overflow is not clear. Usually the particles in the overflow are the smallest particles (from 0 to 10µm). Bigger particles settle quickly and goes to the underflow.

If you use a hydrocyclone, you will be able to separate at 20µm (maybe less) but the thinest particles would still go in overflow. 

For the design of hydrocyclone I would suggest that you give your data to a manufacturer and they will do the design for you (list of renowned manufacturer such as Neyrtec Mineral (France), Krebs (FLS) (Sweden), Weir (England), Outotec (Finland), AKW (Germany), Multotec (South Africa) and many others). 

B
Boyd
7 years ago

Hi Romain, i appreciate you for the insight and suggested manufacturers

D
Dane Smith
7 years ago
Dane Smith 7 years ago
Like

Hi Boyd,

I have a few comments:

  • Are you sending your thickener underflow to a filter? If so, what kind of filter and what excess capacity do you have?
  • In my experience, the above flow sheet change will typical mean a lower overall density, particularly with a stream as fine as yours. Hence the above question (cake form is related to feed desnity exponentially).
  • Removal of the coarser material will mean a much lower density thickener underflow and a much higher chance of poor overflow quality as you are essentially losing the "ballast" for your agglomerates
  • You will also likely see a much higher flocculant usage 
  • You will likely see much more froth generation on the thickener surface.

i would highly suggest you have a cyclone manufacturer model your proposed idea, then have a thickener OEM do testwork on the thickener feed stream with a baseline Vs modified scenario. I think you'll find your proposed solution wont get you what you want.

I think there are a number if reasons why you are likely struggling at the moment:

  • old thickener design and poor feed system performance
  • Under designed thickener (if new)
  • incorrect flocculant choice

I would highly suggest all of these be investigated prior to the cyclone mods.

 

Cheers,

Dane

 

B
Boyd
7 years ago

Thanks Dane for your valuable comments, actually the design of the thickener is somehow not correct and i want to find the cheaper means to over come the current design of the thickener.

Please join and login to participate and leave a comment.