The Pneuflot pneumatic flotation technology, manufactured by MBE Minerals, has been widely used in coal flotation for treating fine coal slurries since 1987, but has also been used for treatment of industrial minerals; ferrous minerals; non-ferrous metals such as copper, lead, nickel and zinc; and for precious metals like gold, silver and platinum.
Conventional agitator-flotation systems are less sensitive to feed variations, but changing conditions, especially where base metal minerals are being processed, decreases the ability to control the process. Likewise, with column flotation technology, the particle/air collision time in a single cell is very low, making selectivity very high. Multiple cells are therefore required to achieve an acceptable yield. The Pneuflot pneumatic flotation cell mixes the air and pulp in a continuous stream and ensures that correctly sized bubbles are fed into the pulp as it enters the cell. This maximises the number of particle and bubble collisions. The system is able to produce a wide range of bubble sizes between 0 and 1 000 µm, allowing the equipment to be used for all flotation stages, from rougher through cleaner to scavenger.
Turbulence in a Pneuflot cell is comparatively low when used on ultra-fine feed materials. The bubble size range in the self-aspirated aerator can be reduced by changing the feed slurry rate using a frequency converter on the motor’s power supply. There are no rotational parts as in agitator cells and unlike column cells, no further air injection is usually needed. Furthermore, special rubber and ceramic materials are used to construct all parts that are exposed to friction. This provides improved wear behaviour and longer service intervals.
Available in sizes ranging in diameter from 800 mm to 6 m, the Pneuflot systems have been successfully installed in a number of industrial applications. Slurry feed rates of 10 to 1,400 m3/h can be achieved in a single cell, depending on cell diameter.