Made with Xara Fly ash The finer ash produced in a coal fired power station, which is collected using electro-static precipatators. Sometimes spelt as 'flyash'. This is also know as Pulverised Fuel Ash (PFA) is some countries. About 85+% of the ash produced is fly ash. Furnace Bottom Ash (FBA) The coarse ash that falls to the bottom of a furnace. The molten ash adheres to the boiler tubes, eventually falling to the base of the furnace. In many furnaces there is a water system that rapdily cools this ash, so called 'wet bottomed' furnace. Usually <15% of the ash produced is FBA. Cenospheres Hollow ash particles that form in the furnace gas stream. Sometime these particles will contain smaller ash spheres. They float on water and are usually collected from lagoons, where ash/water disposal systems are being used. Only 1 to 2% of the ash produced are cenospheres and with the reduction in ash/water transportation, fewer are collected/available. Conditioned ash Where fly ash is mixed with a proportion of water (10 to 20% by dry mass typically) in order that it can be transported in normal tipping vehicles without problems with dust for sale or disposal. Flue Gas De-sulfurisation Where a source of Calcium is injected into the furnace gas stream to remove sulfur compounds. A typical system may consist of ground limestone in water being passed through the gas stream. The sulfur compounds convert the calcium carbonate to calcium sulfate, or gypsum, which is used in the wallboard industry for general construction. The ACAA produced in 2003 a more detailed glossary which you can Download here. Abbreviations & explanation ACAA   American Coal Ash Association.    See http://www.acaa-usa.org/ for more information. ADAA   Ash Development Association of Australia BOFA   Boosted Over Fire Air – a way of reducing NOx   emissions from a power station. BSI   British Standards Institute CEN   European Committee for Standardisation or Comité   Européen de Normalisation – the European standards body CIRCA   Canada Industries Recycling Coal Ash ECOBA   European COal comBustion products   Association e.V. See www.ecoba.org for more information. FABM   Fly Ash Bound Mixture as used in the EU. FGD   Flue Gas Desulfurisation HBM   Hydraulically Bound Mixtures – same as FABM, but not   necessarily containing any fly ash! JCOAL    Japan Coal Energy Center KPI   Key Performance Indicators. Now associated with    environmental and sustainability factors, but can be   associated with any measurable parameter. LOI   Loss On Ignition – the measure of unburnt or partially   burnt coal within an ash sample. NCAB   National Coal Ash Board - Israel REACH   Registration, Evaluation and Authorisation of   Chemicals, the EU registration system for   'substances/chemicals'. SOFA   Separated Over Fire Air – a way of reducing NOx emissions   from a power station. UKQAA  The United Kingdom Quality Ash Association UPS   Polish CCP Union