Sintered Flue Gas Semidry Processing Desulphurization Ash As Cementing Materials

The aim of this work was to evaluate the use of sintering flue gas semidry desulphurization ash (SFGD ash) as cementing materials. The samples of ash came from circulating fluidized bed calcium-based sintering flue gas desulphurization system of 60 m² sintering machine. Based on the component of raw ash and modified ash (changed its component under fixed temperature), batches containing SFGDA ash , granulated blast-furnace slag (GBFS), steel slag, clinker and other admixture for cementing materials were prepared. Specimens were molded using hydraulic press, and their soundness, hydration properties, mechanical properties were determined, micrographs, durability including Acidoresistance, Sulfate resisting , Freeze-thaw resistance and dry shrinkage were studied in accordance with different conserving periods. The results indicate that the batches containing modified SFGD ash up to 20%, steel slag steel 11% to 44%, GBFS 12% to 44%, reducing water agent 0.5%, clinker 23% and CFII 1.5% by mass, meet the cement standard with steel slag and GBFS (GB13592-92, in China). The SFGD ash after modified, when mixed GBFS), steel slag, clinker and other admixture, has necessary requirement to be used as a raw material for production of cement. And the additive of shrinkage reducing agent or expansion admixture should be selected to put into the materials to improve the property in the future.