电炉渣热态改质过程中碱度对胶凝活性的影响

Effects of Basicity on the Cementitious Activity of EAF Slag During Hot Modification Process

从源头上对电炉渣进行热态改质是充分利用熔渣显热、高效回收铁质组分和提高胶凝活性的一种新工艺。以电炉渣为研究对象,用热态改质的方法制备碱度为0.9~1.7的空冷改质渣,研究碱度对改质渣胶凝活性的影响规律。结果表明:碱度从0.9增加到1.7,改质渣的胶凝活性呈先减弱后加强再减弱的变化趋势;当碱度为0.9与1.3时,改质渣的胶凝活性较高。通过差示扫描量热法计算的(differential scanning calorimetry,DSC)曲线放热峰面积可知,碱度为0.9的改质渣中玻璃相含量高;通过拉曼光谱测试结果反应的玻璃网络聚合度可知,碱度为1.3的改质渣中玻璃相反应活性较大。在仅利用熔渣显热的条件下,碱度为1.3的改质渣满足改质条件,胶凝活性较高,28 d抗折与抗压活性指数分别为107%与91%。

Hot modification at electrical arc furnace(EAF)slag tapping process is a kind of new process,which can utilize sensitive heat of molten slag,recovery iron of slag and improve its cementitious activity.EAF slag was modified into the slag with basicity from 0.9 to 1.7 in hot stage.Effects of basicity on cementitious activity of the slag were studied.Results indicate that the activity reduces at first,increases then and declines at last with increasing basicity of modified slag from 0.9 to 1.7.Meanwhile,slags with the basicity of 0.9 and 1.3 have higher cementitious activity.The slag with basicity of 0.9 resultes from the high glass content characterized by exothermic peak area of DSC curves.The slag with basicity of 1.3 is due to the high reactive activity determined by low polymerization degree of glass phase which is tested by Raman spectra.However,the slag with basicity of 1.3 satisfies the modification process by using the sensitive heat of molten slag only and its flexural,and compressive activity indexes are 107%and 91%,respectively.