烧结烟气脱硫协同脱硝副产物在水泥中的应用

APPLICATION OF SINTERING FLUE GAS DESULFURIZATION AND DENITRIFICATION BY-PRODUCTS IN CEMENT

为实现对钢铁行业脱硫脱硝副产物的综合利用,将臭氧氧化脱硝混合半干法脱硫灰作为混合材制备水泥,有望充分利用硫硝灰中组分提高水泥胶凝活性,为硫硝灰低成本资源化应用提供依据。通过对硫硝灰成分表征,以不同硫硝灰添加量为基础,采用机械研磨方法得到水泥成品,系统研究了所制备水泥材料的各项力学指标、环境浸出特性及机理。结果表明,硫硝灰制备水泥浆体流动性及凝结时间满足通用硅酸盐水泥的标准要求,所制备水泥试块的抗折强度3 d≥5.0 MPa、28 d≥7.0 MPa,抗压强度3 d≥25 MPa、28 d≥52.2 MPa,性能优于普通硅酸盐水泥;水平振荡法、醋酸缓冲液法及硫酸硝酸法三种不同浸出方法对不同重金属浸出效果存在差异,且均满足危险废物鉴定标准规定值及Ⅱ类水标准;水化产物的生成促进强度的增强与有害物质的良好固结。

In order to realize comprehensive utilization of by-products of desulfurization and denitrification in iron and steel industry,ozonation and denitrification mixed semi-dry desulfurization ash was used as mixed material to prepare cement.It may fully use the composition of sulfur nitrate ash to improve the cementitious activity of cement and provide reference for low cost utilization of sulfur nitrate ash.Through the characterization of sulfur and nitrite ash composition,cement products were obtained by mechanical grinding method based on different sulfur and nitrite ash addition amount.The mechanical properties and environmental leaching mechanism of the cement material were systematically studied.The results show that the fluidity and setting time of cement slurry prepared from sulphate and nitrate ash meet the standard requirements of general Portland cement.The bending strength of the cement sample prepared is more than 5.0 MPa for 3 d and 7.0 MPa for 28 d,and the compressive strength is more than 25 MPa for 3 d and 52.2 MPa for 28 d,respectively,which are superior to ordinary Portland cement.There are differences in the effects of three different leaching methods for different heavy metals,and they all meet the specified values of hazardous waste identification standards and water-like standards.The formation of hydration products promotes the enhancement of strength and good consolidation of harmful substances.