改性钢渣陶粒的制备及其除磷性能研究

Study on Preparation of Modified Steel Slag Ceramsite and Its Phosphorus Removal Performance

为提高钢渣对水中低含量磷的去除能力,采用镧铁复合氧化物作为改性剂,蒙脱石粉和可溶性淀粉分别作为粘结剂和造孔剂,制备了镧铁复合氧化物改性钢渣陶粒(LFSC)。考察了它的除磷性能,并分析了其微观形貌和化学组成。结果表明,原料中钢渣、改性剂、粘结剂和造孔剂的质量比为50:10:25:15时,1000℃下焙烧30 min制得的LFSC具有良好的除磷性能,且不易破碎。改性钢渣陶粒表面呈现粗糙多孔结构,镧、铁元素大都以氧化物或氢氧化物形式存在于LFSC表面。对于100 mL质量浓度1 mg/L的磷溶液,使用0.5 g LFSC 4 h除磷率可高达99.07%(平衡质量浓度<0.01mg/L);在pH为3~11时,LFSC的除磷率都在93.76%以上。磷在LFSC上的吸附过程符合准2级动力学模型。

In order to improve the removal ability of low content phosphorus from water by steel slag,lanthanum-iron composite oxide was used as modifier,montmorillonite powder and soluble starch were used as binder and pore-forming agent respectively to prepare lanthanum iron composite oxide modified steel slag ceramics(LFSC).The phosphorus removal performance of LFSC was investigated,and its microscopic morphology and chemical composition were analyzed.The results showed that the LFCS had good phosphorus removal performance and high strength while the mass ratio of steel slag,modifier,binder and pore-forming agent was 50:10:25:15,and roasted at 1000℃for 30 min.The surface of the modified steel slag ceramsite was coarse and had porous structure,most of lanthanum and iron in the form of oxides and hydroxides were existed on the surface of the LFSC.For 100 mL phosphorus solution with mass concentration of 1 mg/L,the removal rate of phosphorus could reach 99.07%(equilibrium mass concentration<0.01 mg/L)using0.5 g LFSC in 4 h,and the phosphorus removal rate was above 93.76%in the pH range of 3~11.Adsorption process of phosphorus on LFSC followed the pseudo-second order kinetic model.