一种新型钢渣基免烧陶粒滤料的制备及其性能研究

Preparation and performance study of a new type of steel slag-based non-fired ceramsite filter media

采用免烧工艺以钢渣为主要原料制备陶粒滤料,并用其替代高炉底滤法水冲渣工艺过滤池中的鹅卵石,为钢渣资源化利用提供新思路。在确定基础配比(钢渣:水泥为2.0)后,选取石膏和水玻璃作为激发剂研究其对滤料性能的影响。最终选取石膏添加量为8%作为滤料的最优制备参数,此时滤料颗粒强度为4.14 MPa,1 h吸水率为9.05%,颗粒密度为1.49 kg/m^(3),25次抗冷热冲击后强度降幅仅为3%,过滤速度为5.92 mm/s。借助X射线衍射仪(XRD)与扫描电子显微镜(SEM)对滤料进行物相组成和微观形貌的表征,发现所使用的激发剂可促进钢渣中主要矿物C_(3)S和C_(2)S的水化反应,生成C—S—H类凝胶,这些水化产物相互交织黏结,使滤料内部孔隙率降低,滤料颗粒强度和25次抗冷热冲击性能不断提升。该系列滤料同时也可作为建筑陶粒应用于建材骨料等。

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_(3)S and C_(2)S 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.