The environmentally friendly features of calcium sulfoaluminate (CSA) cements can be enhanced by the use of industrial by-products as partial or total substitutes for the natural materials (limestone, bauxite, gypsum) involved in their manufacture. To this regard, FBC bottom ash (a source of CaO, CaSO4, SiO2 and Al2O3) is worthy of consideration due to further limestone saving and reduced CO2 generation promoted by its high content of uncarbonated lime. Synthetic CSA clinkers were obtained in a laboratory electric oven by heating for two hours at temperatures ranging from 1150° to 1300°C four ternary and eight binary mixtures (with and without limestone, respectively) containing FBC bottom ash and anodization mud or alumina powder (Al2O3-rich industrial by-products, in place of bauxite). X-ray diffraction analysis, carried out on the burnt products, showed a very good conversion of reactants and a high selectivity towards the main CSA cement component, 4CaO•3Al2O3•SO3.
Use of FBC bottom ash as a raw material for the synthesis of low-CO2 cements
TELESCA, ANTONIO;MARROCCOLI, Milena;PACE, MARIA LUCIA;VALENTI, Gian Lorenzo
2012-01-01
Abstract
The environmentally friendly features of calcium sulfoaluminate (CSA) cements can be enhanced by the use of industrial by-products as partial or total substitutes for the natural materials (limestone, bauxite, gypsum) involved in their manufacture. To this regard, FBC bottom ash (a source of CaO, CaSO4, SiO2 and Al2O3) is worthy of consideration due to further limestone saving and reduced CO2 generation promoted by its high content of uncarbonated lime. Synthetic CSA clinkers were obtained in a laboratory electric oven by heating for two hours at temperatures ranging from 1150° to 1300°C four ternary and eight binary mixtures (with and without limestone, respectively) containing FBC bottom ash and anodization mud or alumina powder (Al2O3-rich industrial by-products, in place of bauxite). X-ray diffraction analysis, carried out on the burnt products, showed a very good conversion of reactants and a high selectivity towards the main CSA cement component, 4CaO•3Al2O3•SO3.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
