Artificial additions for cement: reproduction in laboratory of fluidized bed ash

Abstract

This paper presents a experimental laboratory simulation of wastes that will be produced as a result of the implementation of a circulating fluidized bed (CFB) steam generator that is being built in the town of Rio Turbio in the province of Santa Cruz (Argentina ). For this analysis, the information published in the environmental impact study conducted by the Grupo Isolux Corsán SA and Others - JV (2008) was used. The design data associated with the operation of the plant was extracted from said document. This power plant will use raw coal as fuel, thus introducing into the reactor a significant proportion of sterile (an inert material that is extracted with coal composed mainly of clay). Based on fuel and plant operation characteristics, it is expected as a residue of the combustion process a potentially reactive material that could be used as an artificial admixture for cement. Time and temperature needed to generate the specified chemical composition for the residue were the most important parameters in the experimental simulation. In order to achieve expected crystallographic structure of these ashes, the assessment of the cooling method was critical. The results of chemical composition and x-ray diffraction show that, in principle, laboratory simulation can produce ashes similar to those expected to be produced at the power plant. Additionally, from the evaluation of the simulated-ashes characteristics, it seems possible to use the real residue from the steam generator as a pozzolanic admixture for cement.