Use of Fluidized Bed Combustion Ash as Raw Feed in the Manufacture of Calcium Sulfoaluminate Cements

摘要

Both utilization and disposal of fluidized bed combustion (FBC) waste are com-plicated by its chemical and mineralogical composition. It has a quite high content of CaO and CaSO_4 responsible for exothermal and expansive phenomena upon hydration; furthermore, due to the low combustion temperature, it contains a coal ash having a lim-ited amount of glass phase and therefore a poor pozzolanic activity. In this paper, the suitability of FBC waste as raw feed component for the manufacture of calcium sulfoa-luminate cements is assessed, which can be utilized for a wide range of applications. Mixtures containing FBC wastes derived from both laboratory and industrial plants were synthesized into an electric oven in the temperature range 1000°-1300℃. Depending on the proportioning of the constituents of the raw feed as well as on the syn-thesis conditions, burning products having as main components the desired hydraulic phases were obtained.