Powders, Grains, Lumps, Aggregate
Coatings, Environmental, Polishing, Rubber, Specialities
Pumice is a lightweight aggregate which has been used in numerous applications since the Roman Times. It is a volcanic rock consisting of highly vesicular volcanic glass. It is typically light in colour but can also occur darker, and is created when super-heated, highly pressurised rock is violently ejected from a volcano and then cools rapidly within the atmosphere.
Pumice is ground and milled to required specifications for particular application areas. These include for use in lightweight concrete, abrasives, polishes, PCB boards, glass treatment, and in the production of stone-washed jeans. In recent years it has also found an ever increasing market in bio filters and other water filtration systems, and within the horticultural industry. Through years of experience and knowledge we are able to supply pumice powder, grains, pellets, blocks and aggregate.
Pumice grains are used within dual and multimedia filters in waste water, potable water and seawater reverse osmosis (SWRO) treatment plants. Most recently, a major application of pumice grains can be found in the pre-treatment processes of reverse osmosis (RO) desalination systems. The pumice ensures the removal of particulates in gravity and pressure filtration systems thus preventing the fouling of membranes.Recommended grades include the pumice NMP4 and NMP4N grains. In multi-media filters, we are also able to supply supplementary filtration grains including sand and anthracite.
Testing: Further to our detailed specifications, our pumice grades have been tested in action, using a state-of-the-art testing rig. Results include accurate data on back-washing rates vs bed expansion, head loss vs water rate, against variations in temperature and salinity. We also offer comprehensive results on the particle size, porosity, hardness, attrition, density and chemical composition.
Pumice lumps are also used in bioscrubbers and biofilters, acting as a support medium for bacteria. Polluted air passes through the pumice biofilm, where microbes enable the transfer of contaminants into the liquid medium through oxidation. Such units are installed throughout waste water, sewage and industrial effluent systems enabling the treatment of hydrogen sulphide and other volatile organic compounds. Its low density, high surface area, neutral pH and high strength make pumice an ideal material within these systems. Pumice can also act as a longer term solution to fast degrading organic alternatives such as peat, heather and wood chippings.
Pumice is a lightweight aggregate, characterised by low density, excellent abrasivity and white colour. A 5 – 6 mohs, results in a soft abrasive action, making it ideal in the final stages of polishing, or when protection of the product surface is critical. Key applications can be found in the polishing of printed circuit boards, glass, acrylic dentures and automotives.