(Reported to Aufbereitungs Technik September 2003)

IPAS NV of Hasselt, Belgium have purchased an Imhoflot IMF V-45 pneumatic flotation system from Maelgwyn Mineral Services for installation in a coal tailings process plant in the Lugansk region of Ukraine.

The plant should be installed and commissioned by the coming winter. IPAS NV (Industrial Processing Activities and Systems) is an environmental engineering company with offices in Belgium, France and Poland, founded in 1987, specialised in separating primary and secondary raw materials including bottom ashes, silt-water, coal sludge, glass and sieve sands. The IMF 45 flotation system is a highly efficient separation alternative to conventional mechanical cells. The technology consists of intensive pre-aeration using a proprietary self-aspirated in-line device and subsequent froth separation in a 4.5m diameter low aspect ratio cell equipped with a variable froth crowder, and a vertical inlet distributor.

The overall residence time of a single stage separation is less than 3 minutes and due to hydrodynamic efficiency provides high selectivity, with consistent product quality concentrate. Electronic level control can be used to balance variations in feed using a tailings recycle loop. High wear components such as parts of the aerator and distributor are constructed with abrasion resistant ceramics and as the system contains no moving parts maintenance requirements are minimal. The energy for the process is provided by the variable speed centrifugal feed pump, and with total installed power of 80kW the process demonstrates a considerable saving compared with equivalent mechanical systems. The IMF V-45 will treat up to 800m3/h fine coal tailings, and was chosen by IPAS because of their previous successful application of pneumatic flotation.

Maelwgyn Mineral Services of Wales and Germany have recently provided Imhoflot pneumatic flotation systems for potash, coal, platinum and iron ore applications in Europe, South Africa and South America. MMS currently focus development on their innovative G-Cell process incorporating centrifugal froth separation, again without moving parts, and with even lower residence time of around 30 seconds. The process is seen to be the key to providing reduced infrastructure costs suitable for transportable process plants, which would allow the customer to treat small or marginal resources such as tailings ponds. In combination with another innovation – steel belt filter technology, high efficiency, relocatable fine coal and tailings process plants have already been proposed for use in South Africa and Russia.