Monday, 30 January 2017

Column Flotation Popularity and Usage

Courtesy Metso
In the posting of 14 May 2010 I raised the question of whether flotation columns ever realised their potential. The responses suggested that perhaps they didn't, apart from their use as cleaners, the emphasis now, particularly in base metal operations, being more on extremely large, energy efficient, mechanical cells.
A paper published this month in Minerals Engineering examines this question in depth. Greg Harbort and Danica Clarke have reviewed the fluctuations in the popularity and usage of flotation columns.
They conclude that since 1961 column flotation has gone through three distinct rises and falls in popularity. These fluctuations have largely been driven by commodity prices. Within these primary waves there are secondary fluctuations in popularity driven by the rise and fall of individual flotation column manufacturers, the necessity for circuit refurbishment, commodity specific requirements and the effect of capacity saturation, both within commodities and individual countries.
Areas where flotation columns have achieved wide popularity include the Australian, Chinese and USA coal industry, the phosphate industry in the USA and Brazil, and the iron ore industry in Brazil. Within the base metals industry flotation columns are generally accepted in the smaller capacity cleaner roles worldwide.
This is an excellent overview, providing an analysis of over 4000 installed flotation columns, contained in the Amec Foster Wheeler flotation database. Changing trends in column flotation use by type, commodity and geographical region are reviewed. The reasons for the numerous rises and falls in column flotation use are also discussed.
To supplement this fine review, I would appreciate the views of operators who are, or who have been, involved in column flotation applications.
Twitter @barrywills


  1. The comment needs to be taken in the context of a commodity....columns have enjoyed a lot of success in igneous phosphate flotation for many decades starting in the 1970's (USA and Canada) and ending up today with the Eriez columns being accepted as the benchmark in phosphates. For other commodity groups such as base metals "columns" aka non-agitated flotation devices (Jameson cells, Metso Cisa, BGRIMM etc.) have also found application in cleaner applications and have been able to reduce the number of stages in most locations relative to an equivalent mechanical flotation cell circuit.
    Operator comfort zones also play a major role in applying columns to new project flow sheets and existing operations.

    Ewan Wingate, Principal Process Engineer, WorleyParsons Services Pty Ltd, Melbourne, Australia

  2. I think that it is time to call a Column 2018 symposium to hash out the truths or un-truths. I have been in the testing/operation and design of columns for nearly 40 years and I may have some great examples of their applications.
    Roger Amelunxen, Director of Aminpro.

  3. I agree with the views that column flotation came as a storm; perhaps it has its special features as published in many conferences and books. But I am yet to see a good comparitive studies of column and a good conventional cell. A good articulation of where conventional cells do not give the required results and where only columns are better are yet to be brought out; should we use columns at cleaning stage only, if a must?What are the costs of operations/consuption of chemicals/special operating skills required are other points to be brought out.
    I wrote all the above because I came across some instances where high sales pitch was used on the "wonders of flotation by columns and columns only ",

  4. The flotation column unit operation has fundamentally different hydrodynamic and contacting characteristics (ie counter current contacting of the ore particles with the bubbles and the wash water with the froth) than the conventional stirred tank flotation cell. When particles are well liberated, this usually means that the column will have better grade. Also, because the column has a more plug flow distribution (less radial mixing, and therefore less short-circuiting) this typically means a smaller number of units in series, compared with conventional mechanical tanks.

    Some recent papers (Mamani, Perumin 2015 and Knoblauch et al, CMP 2016) have shown the benefits of columns over mechanical cells in certain industrial applications.

    On the other hand, for semi-liberated ore that is not too fine or too coarse, where high recovery is required, mechanical cells are usually the right choice.

    Another approach is to pair sizing units with flotation units, so that the feed properties are optimized to produce the best results, based on the strengths of the flotation technology.

    Eric Wasmund, Eriez Flotation Division

  5. Well lot of research activities are in progress for fine particle processing by flotation. In India it was installed for lead zinc flotation but now, now where. Researchers are working on design of sparger design etc..,but how it competes or substantiate with conventional cells is still a issue.
    Does the cell (column or conventional)impact more or the reagents on which more stress is being given is impacting the process..

    Rama Murthy

    1. Congratulations for helping mineral Industry and bring awareness of importance of Column flotation in mineral Industry.
      In HZL India Vdanta 2002-3 --Innovation was made to reduce silica trapped in between bubbles. 8 % ISM in Zinc could be reduced to 3%. This benefited smelting operation in millions and enhanced smelter capacity. Any one interested can contact us for installation of this system ( SEE LINKED IN FOR DETAILS)

  6. It would be great to hear from the people using columns in practice and I agree with Roger that a conference such as Column 2018 would be a great idea. The potential of columns was not fully achieved, particularly in roughing applications or base metals. It is interesting to see that columns have gained a foothold in the treatment of industrial minerals where gangue entrainment is a major problems leading to numerous stages of conventional cleaning. Andrew Newell

  7. There must be some perspective put in place when looking at the up/down history of column flotation. It certainly is a great tool but certainly did come on strong in the 70's and 80's. However, with the boom and busts of the mining industry, many of the companies that could provide the technical support disappeared. Making matters worse, the proper scale-up techniques were not understood as well as they are today. Because of this lack of understanding, there were many failed installations (i.e., the USA rust belt) that failed miserably during that time. In fact, and I wish I could remember the reference, there are peer reviewed papers from those early days that describe scale-up completely incorrectly.

    Flash forward 40 years and we've come a long way. The technical support is available. Scale-up is much better understood. And most importantly, the sparging systems are much more robust. With these improvements (decades in the making), I can safely say that I've seen successful installations in all types of minerals and all types of applications (i.e., rougher, cleaner, etc). The key is understanding what a column can do, how it is best applied, and then making sure the engineering around the installation is robust.

    Column Flotation 2018 sounds like a great idea.

    -Jaisen Kohmuench
    Eriez Flotation Division - Australia

  8. Dear Roger/Andrew/Jaisen
    Your views on a possible Column Flotation conference are very interesting. However, as you know, MEI already runs a very succesful flotation series of conferences, which your company, Roger, kindly sponsors. If sufficient interest there is plenty of scope for a column flotation session, and we invite anyone interested to submit abstracts to Flotation '17. I doubt whether a conference devoted solely to column flotation would be sustainable, or indeed desirable as developments in this area would be better exposed to the wider flotation community. Interesting that at Flotation '15 there were just 2 papers that mentioned column flotation, so hopefully more in November!

  9. I think that you would be surprised Barry. Perhaps a survey may settle the matter or at least provide guidance. The fact that columns have moved from engineering companies (e.g. Minproc Engineers, BHP Engineering, Minenco Engineers - in the distant past) and mining companies (e.g. MIM)to vendors suggests that they have become mainstream with a substantial following. At the very least, I think a whole day of Flotation19 could be devoted to columns - testing, scale-up, design and operations - a lot of catching-up to be had. Cheers Andrew

  10. I really don't think you can separate columns from other flotation machines - the two go hand in hand after all and no column would be successful without a mechanical cell to back it up in terms of recovering values from its tailings. Mineral processors are interested in technology innovations which includes the best applications of respective technologies , whether columns or mechanical cells. Nothing wrong with a column session at say Flotation 19 but not a whol session!
    Steve Hearn

    1. I agree Steve. Regarding a survey, Andrew, you might like to express your views in the innovations survey currently being carried out by Grinding Solutions Ltd.

  11. Yes, a good look at present practices and survey will through some light. But I feel that the mineralogy/size distribution of particles being processed would really determine the kind of retention time required/how much time needed for unwanted particles to drain back without floating with values and the grades required may also have to be noted(or collected,if possible).
    I still hold the view that it is not conventional or column--


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