【作者】 潘奎勇；

【导师】 杨克锐； 宓振军；

【作者基本信息】 河北理工学院 ， 材料学， 2004， 硕士

【摘要】 本文研究了利用钢渣和熔渣在预分解窑上煅烧硅酸盐熟料的反应机理和工艺技术的若干问题。结果表明,在预分解窑上利用钢渣和熔渣代替铁粉配料,可以明显提高生料易烧性,降低煤耗。并且熔渣配料时,即使熟料中氧化镁含量严重超标,达到5.5%,水泥的体积安定性仍然没有问题,由此可见,利用钢渣和熔渣配料在大型预分解窑上煅烧硅酸盐水泥熟料是可行的。通过冀东水泥集团有限责任公司的实践,证明具有重大的经济效益,社会效益和环保效益。通过易烧性实验、烧结点试验和XRD以及DTA等方法研究表明,钢渣并不能加速CaCO3的分解和固相反应速度,提高生料的易烧性的原因主要是大量的微量元素的存在,降低了烧结点的温度,同时其中的C3S起了煅烧晶种的作用;熔渣在煅烧过程中能够加速CaCO3的分解和固相反应速度,并且以玻璃态存在的大量微量元素更有效地降低烧结点温度,促使反应活化能大幅度降低。因此,熔渣配料比钢渣提高生料易烧性的效果更加明显。熔渣配料引入大量的MgO后,使熟料中氧化镁含量超过国家规定的数量,但是通过压蒸试验表明,不会造成安定性不良。分析其原因,主要是熔渣中的MgO基本上以玻璃态的形式存在,与石灰石和白云石引入的MgO相比,在煅烧过程中反应历程不同,因此熔渣配料在熟料中不易生成方镁石晶体,而更多的是固溶于熟料矿物和玻璃相中,加上预分解窑的熟料冷却速度明显快于一般的回转窑和立窑,因此即使是形成了方镁石,晶体的尺寸也比较小,对水泥的体积安定性影响不大,因此熟料中MgO含量即使达到5.5%仍然不影响压蒸安定性。工业废渣进行配料引入的碱高,可能使S /R比降低,造成坍落度经时损失严重,熟料烧成过程中引入外加硫,适当提高熟料中的S /R比,使其处于0.5—0.7之间,对解决预分解窑目前存在的水泥需水量过高,坍落度经时损失过大,将起积极作用。更多还原

【Abstract】 The reaction mechanisms and the techniques using the raw mix proportioned from the steel slag and the melting slag to burn silicate clinker in the precalcinator kiln were studied. The results show that the burnability of the raw mix is enhanced and the consume of coal is reduced, and the soundness of cement is up to grade all the same even if the content of magnesia in the clinker reaches 5.5 % that goes beyond the limit seriously when the iron powder is substituted by the steel slag and the melting slag. Thus it can be seen that it is feasible that the steel slag and the melting slag are used to produce the silicate clinker in the precalcinator kiln, which has been proved to possess the great economic benefit, the social benefit and the environment benefit through the practice in Jidong cement group limited liability.By the experiment of burnability, sinter point, XRD and DTA, it has been shown that the steel slag can’t accelerate the decomposition of CaCO3 and the solid- phase reaction, and the reasons that the burnability of raw mix can be enhanced lie mostly in the existence of diversiform microelements that can reduce the sinter temperature, at the same time C3S in the steel slag can play a role as crystal seeds in the clinker burning. The melting slag can accelerate the decomposition of CaCO3 and the solid-phase reaction, and reduce the sinter temperature effectively due to the microelements that exist in the vitreous form. Besides, the microelements can decrease the activation energy of reaction in great extent. Therefore the melting slag is able to improve the burnability of raw mix more effectively than the steel slag. Because the melting slag introduces a lot of magnesia, the content of magnesia in the clinker will exceed the national standard. But it is shown by means of the high- pressure steam test that the soundness badness will not appear. The causation mostly consists in that the magnesia exists as the vitreous form in the melting slag, which brings about the reaction course to differ from that when the magnesia is inducted by limestone and dolomite. Thus the periclase crystal does not appear easily, and much more likely the magnesia is solid dissolved in the clinker minerals or in the vitreous form. Besides, owing to the cooling rate of the clinker in the precalcinator kiln is faster than that in the ordinary rotary kiln or in the vertical kiln, the crystal particles will also be undersize even if the periclase crystal comes into being. Therefore the soundness of cement is not affected greatly, and even though the content of magnesia in the clinker reach 5.5% the soundness with the high- pressure steam test is eligible. When the raw mix proportioning using the industrial waste is carried through, the more the alkali is inducted, the lower the ratio of S /R is depressed, which leads the slump loss seriously. In order to elevate S /R in the clinker properly, which is in the range of 0.5~0.7 best of all, the more amount of sulphur is introduced into the clinker in the process of burning. It can bring a favorable role for depressing the excessive water demand and slump loss.更多还原