Froth Flotation (Sulphide & Oxide)

Froth Flotation (Sulphide & Oxide)

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Tank Cells (13 replies)

Raje Singh
8 years ago
Raje Singh 8 years ago

We are running Outotec 50 m3 Tank Cells followed by Wemco Cells (8 m3), in Tanks we just float fines/ultra fines even gangue, but in Wemco it is desired flotation, is there any idea what is going on?

Oberstorm
8 years ago
Oberstorm 8 years ago

I presume size-by-size assays have been performed on the concentrates and tailings from the tank cells?

Is there a reagent (collector) addition between the 50 m3 and the 8 m3 flotation cells? If so, it could be that there is an insufficient collector addition ahead of the 50 m3 ones.

The coarser particles are often weakly attached to the air bubbles - the agitation in the 50 m3 cells may be too intense and slowing down the impeller might help. On the other hand, this may reduce the recovery of the fine/ultrafine particles.

Raje Singh
8 years ago
Raje Singh 8 years ago

The concentrate of Tank Cells is 80% below 45 Micrometer which is disaster!

There is not any point of collector addition between Tanks, but at the head of Wemco we have collector.

I presumed the Outotec should set up the mechanical parameters at Manufacture and those are part of design, so do you mean we can reset up again according to our requirements?

Oberstorm
8 years ago
Oberstorm 8 years ago

The 80% -45 um in concentrate may/may not be a disaster depending on what is the primary grind P80.

One thing to try would be to add some collector at around the mid-point in the line of 80 m3 cells.

With respect to the mechanical parameters of the tank cells, the specifications at the time of order of the tank cells should be reviewed. Ideally, they should have been defined as per the requirements of the flow sheet.

It would be a good idea to discuss the situation with Outotec's after-sale technical support people - they likely will be able to point to most likely means or resolution.

Zander Barcalow
8 years ago
Zander Barcalow 8 years ago

What is the flotation feed size distribution? Is this a new mill or new feed to an existing mill?

Raje Singh
8 years ago
Raje Singh 8 years ago

I think addition of Collector to increase the power of foams is good idea.

The feed size distribution is 80% below 200 mesh, but even inside the feed ore at mine we have a lot of fines/ultrafines, in Wemco cells all fine and coarse minerals could be floated, but in Tanks just we have fine minerals and even fine gangue!

This is an old mill which have been refurbished by substitution of old Wemco Cells at rougher stage by new Tank Cells

(unknown)
8 years ago
(unknown) 8 years ago

Adding collector before the conditioning stages seems a little odd, have you tried to optimize your pulp chemistry before collector addition?

(unknown)
8 years ago
(unknown) 8 years ago

What are floating? Sulphide or oxide copper ore? What type of collector are you using? Iwill suggest you conduct some mineralogy analysis of the concentrate you are getting on each type of cell to have a better understanding of the issue.

Tarun Karakoti
8 years ago
Tarun Karakoti 8 years ago

I liked Tank cells, as they are trouble free operation, and good frothing. Is there any developments made in design after this. As a mineral engineer's point of view and smelting side I feel for cleaning stage you should go for 10 meter column flotation with 1000mm forth bed washing, to get clean concentrate.

Oberstorm
8 years ago
Oberstorm 8 years ago

A flotation concentrate at 80% -45 um vs. a flotation feed at 80% -75 um is on the finer side of things yet not a disaster.

Maybe a hard question - was the replacement of the Wemco cells by the Outotec Tank cells fully engineered and with active participation of Outotec technical people?

Tank cells have vastly different hydrodynamic conditions than the older through cells (Agitair, Denver, Wemco) commonly in used 20-30 years ago. It is not just a substitution based on effective cell volume that one needs to consider.

(unknown)
8 years ago
(unknown) 8 years ago

Can you answer the following!

•Are you conditioning

•If you are: What is the conditioning time and what is the conditioner "tank turn around ability"

•What is the froth depth (Froth depth as percentage of cell depth)

•Have you compared the bubble surface flux of the two machines?

•Have you compared circulation and Froude numbers

•Have you compared the rotor tip Reynolds numbers?

•Let me know and I will help you fix the problem

Hauptsturm
8 years ago
Hauptsturm 8 years ago

It could potentially be a function of the gangue mineralogy and not directly due to the type of cells used. With the increased power in tank cells previously un-floatable gangue could become floatable thereby forcing coarse mineral particles off the bubble surface. You might find the use of different co-collectors or depressants will reduce this effect.

Paul Morrow
8 years ago
Paul Morrow 8 years ago

What is your gangue type? Conditioning strategy? Grinding stability?

Tarun Karakoti
8 years ago
Tarun Karakoti 8 years ago

We encountered same problem in Zinc concentrate. Heavy gangue was floating along with concentrate. 80000 mt concentrate was rejected by smelters. We did R&D and found that big size bubbles entrap gangue and silica (ISM). After Roughing and scavenging we replaced all tank cells with Two COLUMN FLOTATION using Gas spargers of muoltotech to produce stable and very fine bubbles. A froth bed of 500mm was kept to wash with water droplets to remove gangue in-between bubbles. It worked wonders and is in operation for the last 15 years. From 8 ISM it was reduced to 3 ISM. Concentrate grade improved from 48 to 53%Zn. In your case it must be copper. Yes you too can adopt this technology.

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