1、硕 士 专 业 学 位 论 文利用污泥制备劈离砖工艺技术研究摘 要城市污水厂污泥（简称污泥）是污水处理厂排放的一种固体废弃物，含有大量水分（9599%） 、毒害性有机物、致病生物、无机矿物和重金属等，具有产量大、不稳定、易腐败、有毒有害、有恶臭、难处理等特点，对生态环境和人类健康具有长期潜在的危害性。污泥的资源化利用是现阶段污泥处理与处置的主要研究方向，其中比较成熟的技术有土地利用、焚烧、热解以及制备建筑材料等。然而这些现存技术普遍存在着污泥干燥成本高、产品质量难以达标、产品附加值低等缺点和不足。劈离砖作为一种中高档类的建筑装饰用瓷质砖，其原料来源广泛、制备工艺简单、生产成本低，具有很强的实用
2、性和潜在市场竞争力。目前，劈离砖在消纳和利用各种低质原料和固体废弃物方面的优势与潜力日益凸显，相关领域的研究与应用成果日趋成熟。本文提出了利用污泥制备劈离砖的工艺技术，即：将污泥作为劈离砖的主要原料经过配料、湿法球磨、压滤脱水、真空练泥、陈腐、挤压成型、干燥以及烧成等工艺工序制备劈离砖。实验依据传统劈离砖的制备配方设计了不同污泥掺量的系列配方，并通过对各混合料球磨浆料的压滤性能测试、泥段的加工性能测试以及生坯等的干燥性能和烧成性能等实验遴选出了最佳配方（污泥掺量最高的可行配方），并在此基础上进行了详细的中火保温和高温烧结实验。最后，实验对由最佳配方在最佳工艺条件下制备的样品进行了物理化学性能测
3、试及表征。实验结果显示，本实验工艺中的最佳污泥劈离砖配方为污泥掺量高达 60%、英山长石掺量为20.63%、石英砂掺量为 5.2%、高岭土掺量为 14.14%的配方。其混合料经醋酸改性后具有良好的压滤性能，且其泥段的加工性能和湿生坯的干燥性能较好，其最佳的实验室烧成工艺制度为：700中火保温 10 min，1200高温煅烧 15 min。由最佳配方在最佳工艺条件下制备的样品吸水率为 1.03%，断裂模数 24.8 MPa，均能满足国际标准“ISO 13006:1998”对 AI 级劈离砖的要求。XRD 分析测试表明样品以石英为主晶相，另含莫来石和钠长石；SEM 图片显示样品为多孔结构；重金属固
4、化测试表明样品重金属固化效果较好，重金属浸出量远低于标准“U.S. Code of Federal Regulation (40 CFR 261.24)”中的相应要求。本论文直接取用污泥制备劈离砖，无需干燥预处理，同时烧成时生坯中的大量有机物可作为砖坯内燃料，能够节省大量能耗。污泥劈离砖属于陶瓷类产品，对重金属具有很好的固化效应。本产品具有较高的市场附加值，工业生产时可以获得较高的经济效益。综上所述，该技术切实可行有望成为各大城市决策污泥处理处置技术的优选方案，具有较佳的成果应用和产业化前景。关键词：废物资源化 建筑材料 陶瓷 劈离砖 污泥Direct-utilizationofSewageS
5、ludgetoPrepareSplitTilesABSTRACTMunicipal sewage sludge (MSS) is a kind of solid waste discharged by domestic wastewater treatment plants, and contains a great amount of pollutants such as organic contaminants, heavy metals, pathogenic microorganisms and so on, which easily lead to serious secondary
6、 environmental pollutions. Therefore, much attention has been paid to the pollution controls of MSS worldwide, due to the growing social and environmental pressure. Moreover, it is more significant to develop the recycling technologies of MSS while solving its environmental pollutions. Quantities of
7、 investigations in this field have been carried out, and the main technologies include composting, anaerobic digestion, combustion, thermolysis, producing building materials, and so on. However, these as-result resolutions are still hindered considering such problems as high cost of drying pretreatm
8、ent of MSS, low quality and price of the as-received target products.Split tile, a kind of medium-grade and/or top-grade ceramic tiles used for the decoration of buildings, is being more and more popular for its low requirements on raw materials, simple and feasible process technology and its low pr
9、oduction cost. Series of Outstanding studies on the reclamation of low-grade materials and solid wastes to prepare split tiles have been carried out so far.In this paper, a novel proposal on direct-utilization of crude MSS as main raw material to prepare split tiles (i.e. MSS split tiles) was design
10、ed and tested by the authors. MSS split tiles are produced generally by such procedures as wet ball-milling, filter-pressing, vacuum pug-milling, aging, extrusion-forming, drying and sintering according to the as-designed process technology. A succession of formulations of batch mixtures with MSS in
11、corporation from 50% to 60% for MSS split tile was designed. A series of formulation experiments and physical and chemical characterizations, like filter-pressing properties of ball-milled pug, plasticity and handling characteristics of the hydrated mud and the firing properties of the green bodies
12、were carried out. After being comprehensive evaluated on all the key properties, the best formulation (i.e. the feasible one with the highest incorporation of MSS) was determined and some further experiments on the firing procedure of it were explored and developed. In the end, the “best” MSS split
13、tile samples came from the best formulation and prepared through the optimized procedure were characterized and examined.The results confirm that the optimal formulation with maximum MSS content composes of 60 wt.% crude MSS, 15.2 wt.% quartz, 20.6 wt.% feldspar and 14.2 wt.% kaolin and acetic acid
14、as a modifier. The filter-pressing properties of ball-milled pug, plasticity and handling characteristics of the hydrated mud and the firing properties of the green bodies about the optimal formulation are all well with an as-determined firing system: firing the green bodies at 700 for 10 min, and s
15、intering them at 1200 for 15 min. The “best” MSS split tile samples came from the best formulation and prepared though the optimized procedure have the bending strength of 25.5 MPa and the water absorption of 1.14 wt.% respectively, meeting the property requirement of AI-grade split tiles in ISO 130
16、06:1998. XRD test confirms that the samples are mainly composed of quartz and mullite. TCLP test reveals that the samples have a good solidification of heavy metals, and leaching values of heavy metals are far lower than the regulatory levels required by the U.S. Code of Federal Regulation (40 CFR 2
17、61.24).In this paper, without being pretreated, the crude MSS is directly utilized to prepare split tile and the bioenergy in organic matter can be released and recycled during the firing procedure, which is favorable to save energy and cost of recycling MSS. Moreover, the as-resulted MSS split tile
18、, a certain porcelain tile, are satisfying in solidifying heavy metals. And split tile, a popular product that is greatly accept has high added value, which would give rise to a pleased industrially application in future.To sum up, direct-utilization of sewage sludge to prepare split tile proposed and tested in this paper is feasible, and maybe the best choice to dispose MSS, which reveals a beautiful prospect. Keywords: Waste recycling, Building materials, Ceramics, Split tile, Sewage sludge目 录第一章 绪论 .41.1城市生活污水污泥概况41.1.1污泥的产生与排放41.1.2污泥的组成概况41.1.3污泥的环境危害41.2污泥资源化利用研究现状41.2.1土
