Outotec is the provider of the Skim Air flash flotation cell which is the industry standard. We've got lab test procedures for evaluation for Greenfield cases and for retrofits - the procedures are quiet different to conventional flotation tests as there are a number of tricks involved to ensure that the results can be used for prediction of flash performance. If you can PM me with your phone number and email I'll discuss with you what we need before we give out the procedure.

Another good source of flash flotation testing methodology, especially for financial justification is the papers published by Bianca Newcombe as part of her PhD. Most of these are published in Minerals Engineering.

Outotec had a pilot plant in Australia that I trialed at a site 4-5 years ago. It is a good setup but didn't get the copper grade we required and recovered too much gold. (We wanted to suppress gold for the CIP plant that followed the flotation).

We are currently running an Outotec SK500 in the plant I am at in Canada, it is a little more difficult to operate than a standard flotation cell but we have got it running pretty stable with our expert control system. Our only issue with it is that we wear out the course tail valve pretty quickly. It originally lasted 2 weeks; we have changed sleeve style and are now getting over a month per sleeve. The problem is that the course tail valve is too large and thus is running in a mostly closed position increasing the wear. If you use a flash cell use at least 1/2 inch rubber on any discharge pipe work or boxes and do regular maintenance checks.

You’re spot on with your comment on valve wear. Ideally if you can get a smaller valve and can run it -70%+ open this will help.

If the downtime is still more than you'd like we have another alternative. We've had a number of customers with very high sleeve wear due to the nature (and size) of the particles in the Skim Air bottom discharge. The solutions we've developed with Jindex are the 'Chunk Valve'. It’s basically a heavy duty ceramic body valve which is very hard wearing. We've had clients using it for Skim Air bottom discharges take their change out time from monthly to over 12-months! When you start adding up the decrease in maintenance resources and increase in uptime it pays for itself pretty quickly.

If you contact your local Outotec spares people they should be able to get you a price. 

Trying to simulate and quantify the benefits of flash flotation is not easy; you basically need a pilot plant with a cyclone to simulate the size distribution feeding the flash cell. You also need to weigh up the pros and cons of installing flash flotation cells because they add considerably to the capex and opex of a project which is not necessarily offset by the gains(if any) in fine particle recovery improvement.

Following reference may be of assistance.

http://is.gd/YMtLxx

Developed from Bianca's research work through JKMRC.

It is presumed that your client wishes to evaluate flash flotation for an operating plant?

Outotec has developed an excellent bench procedure for performing a first evaluation of flash flotation - notably if a final concentrate grade can be obtained from the stage. It is easy to obtain it from them. The procedure can be applied to laboratory ground feed as well as plant ground feed. It is important to reach final concentrate grade as the particles will be too coarse for cleaning in a conventional circuit.

If the bench scale tests yield the desirable outcome, then small-scale pilot tests would be necessary to ensure that the pulp chemistry at the intended location is conducive to producing the desired concentrate. When pyrrhotite is present in the feed, and the intended location is the cyclone underflow, the REDOX may be so low that pyrrhotite is floating not quite the desired outcome unless one wishes to get rid of pyrrhotite in this fashion.