| Popis: |
CaSO3and CaO are main components in solid waste from flue gas semi-dry desulfurization process. A series of slag cements were prepared from cement clinker and blast furnace slag, in the process of which CaSO3 and CaO were added. The composition and macrostructure of the derived cements were studied in detail with the aid of XRD and SEM. Furthermore, the influence of amount of CaSO3and CaO on the mechanical properties and setting time for slag cement were evaluated, the mechanisms of which were also discussed. The results show that due to the formation of AFt and AFm in the hydration process, the CaSO3has an obvious setting retarding effect on the slag cement, and quality slag cement can be obtained when the amount of slag and CaSO3are 20% and 2%, respectively, the compressive strengths of which at 3, 7, 28 d are 30.8, 39.1, 53.7 MPa, and bending strengths at 3, 7, 28 d are 9.6, 10, 11.9MPa, respectively. Besides, CaO added which can play a role of alkali-activator for slag cement can not cause the soundness problem of slag cement. |
