【作者】 杨雷；

【导师】 马保国；

【作者基本信息】 武汉理工大学 ， 建筑材料与工程， 2007， 博士

【摘要】 危险废物的处理技术,是当前全世界共同面临的一个十分严重和紧迫的问题。含重金属的危险废物在处理时有其特殊性和危险性,处理工艺和技术设备不当,不但处理效果差,而且极易造成严重二次污染。而以往常用的传统技术方法,在处理含重金属的危险废物时均有不同的缺陷和问题。相比较而言,新型干法水泥工艺本身工业规模巨大,煅烧熟料时的密闭高温碱性环境,以及最终水泥熟料产品的有效固化作用,均使得这项技术在处理含重金属的危险废物时,具有得天独厚的明显优势。另外,论文研究了高温区废物中的重金属与熟料矿物之间的反应过程和机理、重金属的存在形态的变化。还研究分析了重金属固化机理,确定其溶入固溶体的溶入率,以及进入熟料矿物形成固溶体后,水泥熟料矿物组成的变化和水泥熟料性能的变化。最后,检测了载体（熟料）的环境安全性,对不同龄期的水泥进行了组成、重金属浸出值的测试,以分析和研究载体的残余毒性及对环境的长期安全性。通过研究和分析,论文得到了下列结论:（1）基于新型干法水泥工艺的技术优势和工业特点,在处理含重金属元素的危险废物时,相比其它技术方法,新型干法水泥工艺固化重金属更彻底,可有效避免废气、灰渣等二次污染问题,实现高危害废弃物处理过程中的全程生态化和产品的高质量的协调统一。（2）随着混合废弃物掺加量的逐渐增大,生料烧结性能得到了很大改进,有的重金属减少f-CaO、提高熟料质量有最佳掺量,超过了限量f-CaO反而增多,比如PbO和Cr₂O₃;有的重金属能大幅度减少f-CaO,改善效果明显,如MnO₂、CuO、Ni₂O₃、SnO₂、Co₂O₃;有的少量即可改善熟料质量,再增加掺量,变化不大,如CuO和NiO。（3）重金属的离子半径对熟料的烧结、矿物形成、液相形成、以及熟料强度有一定的影响:随着离子半径的增大,所掺重金属氧化物对生料易烧性的影响成一个有利的大体趋势;重金属元素对促进熟料中C₃S的形成影响是随着离子半径的逐渐增大而愈趋明显;通过对掺入重金属氧化物的熟料做SEM分析,从图片上可以看出有的重金属的加入是不利于熟料液相的生成,但这种情况随着离子半径的增大可以逐渐改善甚至促进液相的形成,这是结合XRD数据分析得出的结论;通过对掺入重金属氧化物的熟料做强度测试,可以发现一个规律,随着离子半径的不断增大,它对熟料的强度影响也是由消极专为积极。掺MnO₂、Co₂O₃、Cr₂O₃的样品明显比基准样生成的液相多,而掺V₂O₅,Ni₂O₃的样品明显比基准样生成的液相少。（4）实验室模拟煅烧条件下,重金属元素以1.0%掺量单掺时的固化率分别为:Mn81.2%、Cr 67.3%、Co 72.8%、Ni 58.5%、Cu 61.0%、Zn 65.9%、Cd52.7%、Pb 63.1%、As 78.4%、V80.4%;混掺时的固化率分别为Mn 86.0%、Cr 87.7%、Co91.4%、Ni89.5%、Cu 80.9%、Zn 81.1%、Cd75.1%、Pb 79.6%、As 88.3%、V87.6%。单掺时不同重金属元素固化率不同,有的较高,有的较低,而复合掺加时互相影响,固化率均比单掺时有所提升。（5）重金属离子的浸出量因重金属的种类而异,与其在试块中的含量无直接关系。采用去离子水作为浸取液,结果各种重金属的浸取值都很小,说明重金属元素通过物理包容、化学吸附、结晶作用等进入了熟料的内部,在中性溶液中熟料保持稳定,因而重金属便稳固的保留在结构中,很难浸出。当调整溶液PH为酸性时,重金属的浸取值大幅度上升,但仍然远低于国家浸出毒性鉴别标准。说明水泥熟料对重金属的固化效果很好。（6）对重金属元素在熟料主要矿物相中的选择性固溶有决定影响的主要有两个方面的因素:①熟料主要矿物相的晶体结构;②重金属元素自身的条件。Zn主要存在于熟料的中间矿物中;As、Co、Cu和Ni大部分存在于熟料的中间矿物相中,但在C₃S和C₂S中也有存在;Cd和Pb则不能明显区分出主要存在于熟料的哪个主要矿物中,可以认为它们是比较均匀地分布在熟料主要矿物中;Cr则由于部分区域含量过于集中而压制了其他区域的反射波,因而在面扫描图像中不能很好地显示,有待于寻求新的测试研究方法。（7）当以2.0%比例掺烧污泥、旧电池、荧光粉、油墨时,其中所含的各重金属元素的固化率均在99%以上,这说明利用熟料烧成来固化危险废物中的重金属效果很好。而且2.0%的掺量低于饱和掺量,在实际的工业生产中应用时,由于干法窑内有充足过量的氧气,且烧成环境为碱性,可中和酸性气体,焚烧全过程均在负压下完成对重金属固化效果更好,所以危险废物的掺量可适当增加。（8）掺烧2.0%废弃物时,熟料的重金属浸出值均远小于GB5085.3-1996（危险废物鉴别标准-浸出毒性鉴别）浸出毒性标准。这是因为大部分的重金属元素在熟料烧成过程中参与了熟料矿物的形成反应,由于熟料烧成是高碱性的环境,加上重金属相互作用促进固化反应,最终各种重金属元素都转变成难溶的化合状态,被固定于矿物晶格中。如果将新型干法水泥工业与废弃物处理结合起来,组成生态工业园区,使生态水泥工业与环保产业协同发展,既能有效处理生活垃圾及危险废物,又可在生产水泥时部分解决原燃料问题,创造良好的社会效益和经济效益,这也是21世纪生态水泥工业的发展趋势。更多还原

【Abstract】 The disposal technic of the hazardous waste is a very serious and urgent problem faced by the whole world.As this disposal of the hazardous waste containing heavy metal（HM）is special and hazardous,unproper technics and facility would be inefficient and lead to secondary pollution.Traditional technics all have limitations and demerits.With the giant scale of cement industry,alkaline and high-temperatured calcination circumstance and clinker solidification,precalcining cement technic comparatively have some advantages in the dispose of the hazardous waste containing HM.On the base of synthetically analysis of different waste disposal technics,the thesis clarifies the feasibility and advantages of precalcining cement technic in the disposal of the hazardous waste containing HM,studies the reaction mechanism between HM and clinker phase and the change of the existing conformation of HM.The thesis also studies the heavy metal stabilization mechanism and proportion,the change of clinker phase,and the security lixivium of HM in the cement clinker.The thesis draws following conclusions;（1）Compared with other technics,while disposing hazardous waste containing HM precalcining cement technic is much more clean and thorough.（2）With the increacing of the adulteration proportion of HM,the calcination of cement raw material is improved distinctly.PbO and Cr₂O₃ could decrease f-CaO but has a optimal adulteration proportion.Improvement effect of MnO₂,CuO,Ni₂O₃,SnO₂ and CO₂O₃ is very remarkable.A small quantity of CuO and NiO could markedly improve the quality of cement clinker,while the effect would almost be changeless with the increace of adulteration proportion.（3）The ionic radius of HM could influence the clinker sintering,formation of mineral phases and liquid-phase and the clinker Strength;With the augment of the ionic radius of HM,the burnability of cement raw material, the formation of C₃S and the clinker Strength is gradually increasing.According to the study of SEM and XRD test result,the adulteration of some kind of HM might be disadvantageous for the formation of liquid-phase.But with the augment of the ionic radius of HM,it might gradually improve and even increase the formation of liquid-phase.The liquid-phase of clinker adulterated with MnO2,C0203 or Cr₂O₃ is much more than that without those HM.While the liquid-phase of clinker adulterated with V₂O₅ or Ni₂O₃ is much less than that without those HM.（4）Under the situation of laboratory,the HM incorporation proportion of which the single-adulteration proportion is 1.0%respectively is;Mn 81.2%,Cr 67.3%,Co 72.8%, Ni 58.5%,Cu 61.0%,Zn 65.9%,Cd52.7%,Pb 63.1%,As 78.4%,V80.4%.While the disposal proportion of the multiple-adulteration HM respectively is;Mn 86.0%,Cr 87.7%, Co91.4%,Ni 89.5%,Cu 80.9%,Zn 81.1%,Cd75.1%,Pb 79.6%,As 88.3%,V87.6%.（5）The leaching quantity of HM in clinker has relations with the kind of HM,while not with the quantity in raw material.The leaching quantity of HM in clinker is bally tiny,wich means the HM has entered the stable alkaline inner space of clinker through physical package,chemical adsorption and crystallization process.When adjust the leaching liquor to be acidic,the leaching quantity of HM would increase greatly,which convincingly testifies the good HM disposal effect of cement clinker.（6）The incorporation of heavy metals to different clinker minerals is selective;Zn is concentrated in the interphase of clinker;As,Co,Cu and Ni is mainly incorporated by C₃A and C₄AF,but also partly in C3S and C₂S;Cd and Pb can not be separated clearly from interphase and C₃S and C2S,they are equably distributed in those mean clinker minerals.（7）When the raw cement material adulterated with sludge,battery,phosphor and printing ink at the proportion of 2.0%,the incorporation proportion of riM is all above 99%. In actual situation,the air circumstance in precalcining cement kiln is alkaline、close and negative-pressured,which is advantageous for the incorporation of riM in the waste.（8）When the raw cement material adulterated with sludge,battery,phosphor and printing ink at the proportion of 2.0%,the lixiviation proportion of HM in the waste is far below the national criterion.Combining the precalcining cement industry and the diposal process of domestic waste and hazardous waste containing HM,we would create an ecological united industry. So we could dispose the hazardous waste contenning HM more effectively,and partly substitute some cement material at the same time.And this would definitly be the development direction of ecological cement industry.更多还原