Method of processing the fluidised-bed ash obtained in the filters

Fluidised-bed ash which is obtained, in particular, in the combustion of washery tailings and is carried out together with the combustion gases and retained in the filter, can be fed to a useful utilisation if it is intensively mixed with a binder and then is combined and mixed with nuclei-forming coarser granular material which has previously been moistened through to saturation. The mixed product is then subsequently stored for curing and is then used as aggregate. Optimum matching to the demand is possible because the method provides that the coarser granules in the particle size range from 1 to 10 mm are fed in as nucleus-formers, with the particle size spread and the proportion of granules being targeted to the application of the aggregate to be produced in each case, by the addition of the nucleus-formers. Besides cement, lime or gypsum can also be used here as binder, with the added amount of lime and gypsum to be determined taking into account the active amount of lime present in the fluidised-bed ash or as a function of the highly dewatered anhydrite proportion present therein. The material of optimum particle size and nature of particles can then be used as light-weight aggregate for the widest range of fields of application.