Imhoflot Pneumatic Flotation Technology

Imhoflot™ Pneumatic Flotation Technology

Imhoflot™ Operating Principles

Imhoflot™ technology, distinctive and unique principles of operation:

  • Collection / contact process occurs inside the aeration unit (not in the cell);
  • Energy for the particle / bubble contact is supplied by the air pump, eliminating moving parts;
  • Proprietary aeration systems are intensive and self-aspirating;
  • The separating vessel operates without mechanical dispersion of air and process pulp;
  • Residence time in the separating vessel for separation of concentrate and tails is reduced to a minimum;
  • The design features of the G-cell decrease entrainment of non-floating components.

Applications

Two types of Imhoflot™ flotation cells have been developed, namely the “V” cell and the “G” cell, providing floating technology for most applications. Both designs can be used in rougher / scavenger applications, whereas the G cell, with its superior selectivity between valuable minerals and gangue, is preferred for cleaner applications.

Classic Design – Vertical cell

Classic Design – Vertical cell

  • Central cell feed is vertical and free draining
  • Self-aspirating aeration device
  • Pulp distributor is located in the separation zone
  • Cylindrical separator with peripheral froth collection
  • Conical froth crowder permits fine control of froth dynamics
  • Tailings flow and discharge through conical hopper
  • Overflow level control facility, with short-circuit prevention
  • Recycle flow and level control facility

Advanced Design – G and H Cells

Advanced Design – G and H Cells

The new design incorporates features for enhancing separation in difficult process applications.

  • Dynamic, centrifugal action improves the mobility of rising air bubbles, promoting disengagement, whilst reducing entrainment; and
  • Smaller volumes allow for more stages, increased separation and lower costs.

Operational Design Features and Benefits

  • Imhoflot™ flotation cells are designed for high throughput capacity per unit and can endure wide variations in feed grade;
  • Every Individual Imhoflot™ flotation cell has a constant feed rate as per set feed pump, eliminating sliming and concentrate production caused by fluctuations in feed rates;
  • The process caters for the recovery of all variations of floating minerals, reducing investment and operating costs;
  • The space required is much smaller compared to other flotation systems and on the same level (ground level) as compared to conventional cells cascading from height;
  • Space requirements, compared to other flotation systems are a minimum, limited to the same level;
  • It is a modular design process, therefore:
    • The design of the distribution unit, aeration unit and separating cell allows for the easy assembly and replacement of parts;
    • Imhoflot™ flotation cells can be automatically controlled and require minimum supervision via PLC control;
    • A maintenance friendly process, occasional and simple replacement of parts, confined to the pump and aeration unit;
    • Imhoflot™ flotation excels in coarse and ultra-fine mineral recovery applications; and
    • Critical parts are manufactured from ceramic and wear resistant materials.

The flotation cells are designed for a variety of throughput requirements, ranging from small pilot sized cells with a diameter of 0.8m, processing 6 – 10 m3/h of feed; to cells with a diameter of 6.5m, handling feeds of 1500 m3/h.

The flow rate is dependent on the feed pressure and rate of concentrate removal. A higher concentrate removal requires a higher throughput.

Scale-up and Flowsheet Layout

MMS has extensive experience in plant layouts regarding pneumatic flotation systems. Since the conception of pneumatic flotation in the 1980’s, a large database of information has been accumulated. Our design layouts are based on standard laboratory tests. The mineral being floated determines the number and size of cells in series required to achieve optimal recovery, and the desired grade of the mineral will determine the number of steps required.

As per examples:

  • A single unit is sufficient to recover product with a low percentage of ash for fast floating coals;
  • Industrial minerals – applications requiring long flotation times of over 30 minutes – multiple cells are needed.

Considerable savings in energy and cost are achieved when compared to other forms of flotation. Three conventional cleaning stages, required to produce market / smelter grades of a base metal or pyrite, can be replaced with one cleaning stage using the Imhoflot™ process.

Testing

Testing of an ore is done by using a pilot scale G08 cell with a throughput of 2 t/h. The ore is tested by milling it to the required size, conditioning with the correct chemicals and processed through the G-cell to achieve flotation. The flotation tailings is passed through the cell a number of times and the assay results of the products and their mass recoveries are used in a flotation simulation package.

Flotation Technical Support

Our engineering staff members are specialists in various types of flotation process operations, from a broad range of industries. We provide a complete range of customer services, from pilot scale testing, process design, manufacturing, installation, commissioning and after-sales service.

Technical backup is exceptional due to a world-wide network of agents and associates with expert advice. Liaison with the client throughout the project stages ensures an optimum solution for the specific application.

Installations

The following flotation plants are operating with Imhoflot™ pneumatic flotation cells:

Customer

Country

Material

Los Pelambres

Chile

Molybdenum/copper sulphides

Belaruskali/Passat

Belarus

Potash

Vazantes

Brazil

Lead / zinc sulphides

Dorfner

Germany

Kaolin, cleaning step

Promintech

UK

Fly ash

Kali + Salz

Germany

Potash

Stockhausen

Germany

Coal

Kali + Salz

Germany

Potash

CMH

Chile

Iron Ore, reverse flotation

K+S GmbH

Germany

Potash

IPAS

Belgium/Ukraine

Coal tailings ponds

Techno-Agrar

Germany

Coal / iron ore

SIU

USA

Coal

CMP  Romeral

Chile

Iron ore, reverse flotation

Belaruskali

Belarus

Potash

Gebr. Dorfner

Germany

Kaolin

Zap-Sib

Russia

Coal

Titanium Resources

Sierra Leone

Mineral sands, reverse flotation

Rocktron

UK

Fly ash

IDM

Brazil

Pilot units, different ores

 

Iron Ore V-cell flotation plant

Iron ore V-cell flotation plan

 

Kaolin G-cell flotation plant installation

Kaolin G-cell flotation plant installation

Technical Papers

For further reference literature concerning pneumatic flotation, refer to the list below from recent publications. These articles are available on the downloads page.

  • Sanchez-Pino, S., Sanchez-Baquedano, A., Imhof, R.M, (2008). Imhoflot G-Cell Pneumatic Flotation Technology for Fine Particle Applications. PROCMIN 2008 V International Mineral Processing Seminar, 22-24 October 2008, Santiago, Chile.
  • Imhof, R.M., Fletcher, M.G., Singh, A.A., Vathavooran, A., (2007). Application of Imhoflot G-Cell Centrifugal Flotation Technology. SAIMM Conference, Flotation Cell Technology in the 21st Century, 20 June 2007, Johannesburg, South Africa.
  • Sanchez-Pino, S., Sanchez-Baquedano, A., Imhof, R.M., Battersby, M. J. G., (2006). Is Bigger Always Better in Flotation? The Imhoflot G-Cell.  PROCMIN 2006 IV International Mineral Processing Seminar, 22-24 November 2006, Santiago, Chile.
  • Imhof, R.M., Fletcher, M.G., Singh, A.A., Vathavooran, A., (2007). Application of Imhoflot G-Cell Centrifugal Flotation Technology. SAIMM Conference, Flotation Cell Technology in the 21st Century, 20 June 2007, Johannesburg, South Africa.
  • Battersby, M.J.G., Fletcher, M.G., Imhof, R.M., Singh, A.A., Puder, F., (2005). The Advantages of the Imhoflot G-Cell Pneumatic Flotation Process with Centrifugal Froth Removal – Two Case Studies. Randol Innovative Metallurgy Forum, 21 – 24 August 2005, Perth, Australia.
  • Imhof, R.M., Battersby, M.J.G., Parra, F., Sanchez-Pino, S., (2005). The Successful Application of Pneumatic Flotation Technology for the Removal of Silica by Reverse Flotation at the Iron Ore Pellet Plant of Compania Minera Huasco, Chile. Centenary of Flotation Symposium, 5 – 9 June 2005, Brisbane, Australia.
  • Mohanty, M.K., Huang, Z., Gupta, V., Biswal, S.K., (2005). Perfomance of the Imhoflot G-Cell for Fine Coal Cleaning. Centenary of Flotation Symposium, 5 – 9 June 2005, Brisbane, Australia.
  • Sanchez-Pino, S., Imhof, R.M., Sanchez-Baquedano, S., Rojos-Tapa F., (2003). Pneumatic Flotation Technology – Experience in the Chilean Mining Industry. Copper 2003, Santiago, Chile.
  • Imhof, R.M., Battersby, M.J.G., Brown, J.V., Lotzien, R.M., Kleefeld, J., (2003). Development of Pneumatic Flotation Incorporating Centrifugal Separation. XXII International Mineral Processing Congress, 28 October-3 September 2003, Cape Town, South Africa.
  • Battersby, M.J.G., Imhof, R.M., Brown, J.V., (2003). The Imhoflot G-Cell – An Advanced Pneumatic Flotation Technology for the Recovery of Coal Slurry from Impoundments. SME 2003 Annual Meeting 24-26 February 2003, Cincinnati, USA.
  • Sanchez-Pino, S., Imhof, R.M., Sanchez-Baquedano, S., Rojos-Tapia, F., Fernandez-Garcia, M., (2003) Pneumatic Flotation Technology – An Interesting Experience in the Chilean Mining Industry. CIM 35th Canadian Mineral Processors Operators Conference, 21-23, January 2003. Ottawa, Canada.
  • Melendez, M., Parra, F. (2002). Uso de Celdas Neumaticas en Flotacion Inversa de Fierro CMP, Chile. Workshop: Procesamiento de Minerales, 23-25 October 2002, Antofagasta, Chile.
  • Imhof, R.M., Battersby, M.J.G., Ciernioch, G. (2002). Pneumatic flotation – An innovative application in the processing of potash salts. SME 2002 Annual Meeting, 25-27February 2002, Phoenix, AZ, USA Preprint 02-162.
  • Brown, J.V., Imhof, R.M., Lotzien, R., (2001). Self-aspirating aeration reactors for pneumatic flotation and other applications.  IX Balkan Mineral Processing Congress 11-13 September 2001 Istanbul, Turkey.
  • Imhof , R.M., Brown, J.V., (2000).  Imhoflot – Evolution of pneumatic flotation. Major Trends in Development of Sulfide Ores Up-Grading in the 21st Century Conference Proceedings , 24-28 April 2000, Norilsk, Russia.
  • Imhof R M, (1999) Sortieren, Innovationen und Anwendungen, TU Berlin 1999. “Agitar cells, columns and pneumatic flotations – their characteristics in the techniques, their applications for raw and waste materials.”
  • Imhof R M, (1999) Freiberger Forschungshefte 1999 Berg und Hüttenmännischer Tag.”Pneumatic flotation in general and as example an application in a soil remediation plant.”
  • Imhof R M, Hofmeister S, Brown J V, (1994) Sixth Australian Coal Preparation Conference, Mudgee NSW “Developments in EKOF Pneumatic Flotation Technology.
  • Imhof R M, Lotzien R M, Sobek S, (1993) XVIII International Mineral Processing Congress Sydney. “Pneumatic Flotation: a Reliable Procedure for a Correct Plant Layout.”
  • Imhof R M, (1993) Aufbereitungstechnik (34). “Five years of Ekoflot: Pneumatic Flotation on the March.”
  • Imhof, R.M. (1988). Pneumatic flotation – a modern alternative. Aufbereitungs Technik  29 (1988) Nr. 8 pp 451-458.
  • Bahr, A., Imhof, R.M., Ludke, H. (1985) Application and sizing of a pneumatic flotation cell. Min. Proc. Congress, Cannes, France.