The Influence of FGD Gypsum Fabricated from Limestone Sludge on Cement Properties

For the purpose of reducing the amount of limestone, which is used as a desulfurization agent to absorbing SOX gas in thermal power plants, and to recycle limestone sludge generated from a steel mill, limestone sludge was utilized as a desulfurization agent. In this study, cement, made of flue gas desulfurization (FGD) gypsum obtained in a desulfurization process using limestone sludge, was manufactured then, experiments were conducted to identify the physical properties of the paste and mortar using the cement. The results of the crystal phase and microstructure analyses showed that the hydration product of the manufactured cement was similar to that of ordinary Portland cement. No significant decline of workability or compressive strength was observed for any of the specimens. From the results of the experiment, it was determined that FGD gypsum manufactured from limestone sludge did not influence the physical properties of the cement also, quality change did not occur with the use of limestone sludge in the flue gas desulfurization process.