Abstract:
The non-burning process was adopted to prepare ceramic granule filter media with steel slag as the main raw material. It was used to replace the cobblestone in the filter tank of the blast furnace bottom filtration water flushing slag process, providing a new idea for the resource utilization of steel slag. After determining the base ratio of steel slag to cement of 2.0, gypsum and water glass were selected as activators to study their impact on the performance of the filter media. Finally, an 8% gypsum addition was selected as the optimal preparation parameter for the filter material. At this time, the particle strength of filter media was increased to 4.14 MPa, the 1 h water absorption rate was 9.05%, the particle density was 1.49 g/cm
3, the decrease in strength was only 3% after 25 times of cold and hot impacts, and the filtration speed was 5.92 mm/s. With the help of X-ray diffractometer (XRD) and scanning electron microscope (SEM), the physical composition and microscopic morphology of the filter media were characterized. It was found that the exciter used could promote the hydration reaction of the main minerals C
3S and C
2S in the steel slag to produce C—S—H type gels, and these hydration products intertwined and bonded to reduce the porosity inside the filter media and improve the filter media particle strength and 25 times of cold and hot impacts continuously. This series of filter media could also be used as construction ceramic pellets for building materials, such as aggregate.