城市污泥制备多孔陶瓷填料的试验研究

以城市污泥12～20%、石英24～40%、涂装废水絮凝污泥20～30%为主要原料,煤炭20～30%为造孔剂,焙烧温度为1230～1250℃,保温时间30min烧制多孔陶瓷填料。制备的多孔陶瓷填料吸水率为57.2%,显气孔率为60.89%,体积密度为1.065g/m3,抗压强度为1.8MPa,耐酸性为97.1%,耐碱性为98.3%,为城市污泥的处理、处置和再利用提供了新的途径。     

造孔剂对粉煤灰-城市污泥多孔陶瓷性能的影响

以粉煤灰和城市污泥为主要原料,使用淀粉和稻壳为造孔剂,再辅以膨润土、无水硅酸钠为添加剂制备多孔陶瓷。对多孔陶瓷的性能进行了研究,采用XRD、SEM表征多孔陶瓷的微观结构。结果表明,使用稻壳和淀粉作造孔剂都能制备出具有一定的强度和显气孔率的多孔陶瓷,使用稻壳作造孔剂时性能略优于淀粉。当使用40%量稻壳作造孔剂时,可制备出的显气孔率为52.81%,抗折强度9.12 MPa,气孔呈三维连通的优质多孔陶瓷。     

利用城市污泥/煤矸石制备多孔陶粒的研究

以煤矸石和城市污泥二种原料制备了多孔陶粒,研究了不同配比、不同烧结温度对多孔陶粒体积密度、吸水率以及孔隙率等性能的影响。结果表明,原料配比中污泥的比例应小于50%,当城市污泥掺量在20-50%,烧结温度为1120℃,保温1 h时,所制备的多孔陶瓷密度在1030-1200 kg/m3、显气孔率在26%-50%、吸水率在23%-35%。城市污泥中有害重金属元素在陶粒中得到有效固化,不会对环境造成的二次污染。     

用于隔热保温的多孔氧化铝陶瓷的制备与研究

多孔氧化铝陶瓷具有耐高温、低热导率等特点,是工业窑炉的隔热保温的首选材料.实验以α-Al2 O3、煅烧铝矾土、苏州土为主要原料,采用物理发泡和注浆成型结合的方法制备了具有高气孔率、低热导率的多孔氧化铝陶瓷样品.通过正交实验确定了发泡剂的最佳配方为SDS添加量为0.5 g·L-1、CTAB添加量为0.3 g·L-1及水质量分数为50wt％.并探究了烧成温度对多孔氧化铝陶瓷样品的物理性能、相组成、热导率的影响,结果表明,经1500℃烧成后的最佳配方样品吸水率为13.71％,气孔率为33.14％,体积密度为2.42 g·cm-3,在300℃下测得热导率为0.83 W·m-1·K-1.本实验制备的多孔氧化铝陶瓷样品的相组成为莫来石和刚玉,由于具有大量的气孔,相同能量下气体激发出的声子数量远少于固体,热导率远远低于固体,导致热导率低.     

原料配比对工业固废多孔陶瓷性能和形貌的影响

为最大限度地利用工业固废,以镁渣、粉煤灰、电石渣等固废为原料,经高温烧结制备多孔陶瓷材料,研究了三种固废原料的配比对多孔陶瓷烧失率,气孔率,吸水率,体积密度,抗压强度,微观形貌以及物相的影响.实验结果表明:烧结温度1150℃,保温时间为4 h,镁渣、粉煤、电石渣配比为70:25:5时,所制备的多孔陶瓷具有最大抗压强度,98 MPa;配比为60:15:25时,多孔陶瓷具有最大气孔率,57％;配比为60:30:10时,多孔陶瓷骨架完整,微孔分布均匀.多孔陶瓷的物相主要以CaO和SiO2高温反应的产物偏硅酸钙,硅酸二钙或硅酸钙镁为主,含有少量铝硅酸盐和铁酸盐.     

SiC@OCP发泡剂用于制备以赤泥和瓷砖废料为原料的多孔陶瓷

在改性的Pechini工艺中添加聚乙二醇(PEG)后在碳化硅颗粒表面沉积磷酸八钙(OCP)制备得到SiC@OCP发泡剂.PEG的分子量对制备的SiC@OCP发泡剂的物相、形貌和烧成性能都有影响.在含11wt％赤泥和47wt％瓷砖废料的原料中加入SiC或SiC@OCP发泡剂,经配料、压制和烧成工艺制备得到多孔陶瓷.以SiC@OCP为发泡剂制备的多孔陶瓷的体积变化率、开孔孔隙率和吸水率要远低予以SiC为发泡剂制备的多孔陶瓷,这与多孔陶瓷内孔结构的调控机制,即OCP包裹后对SiC的高温氧化行为产生影响有关系.研究所获得的结果为多孔陶瓷发泡剂的制备、赤泥和瓷砖废料的综合利用提供有益的参考.     

无机盐/石英基复合相变储能材料多孔陶瓷基体的制备

以石英为骨料,钾长石为高温粘结剂,木炭为造孔剂制备无机盐/石英基复合相变储能材料用的微米孔石英多孔陶瓷基体,采用正交实验法系统研究了骨料颗粒粒度、造孔剂粒度、造孔剂含量、高温粘结剂含量及烧成温度对石英多孔陶瓷的显气孔率和抗折强度的影响.研究结果表明,影响石英多孔陶瓷抗折强度的最主要因素是长石含量,其次是骨料粒度和造孔剂粒度;影响石英多孔陶瓷显气孔率的主要因素是造孔剂含量.制备微米孔石英多孔陶瓷的优化配方和工艺是:石英、木炭和长石均过325目筛,三者质量比为7:2:1,烧成温度为1270f,保温时间为1h.该陶瓷具有以下优良的性能:显气孔率为55.12％,体积密度为1.14 g,/cm3,抗折强度为3.14 MPa,抗压强度为7.12 MPa,平均孔径为13.87 μm且孔径分布范围较窄,96％的气孔孔径在9～21 μm之间.     

氧化钙含量对3-1型多孔压电陶瓷性能的影响

利用海藻酸钠特殊的螯合性能,以CaCl2为固化剂,制备出了内部具有高度定向孔道的3-1型多孔PZT陶瓷.本实验配制固含量为10wt％的PZT陶瓷浆料,可以制备出孔径为200 μm,孔隙率高达85％的多孔PZT陶瓷.研究了CaO含量对多孔PZT陶瓷电学性能和显微硬度的影响规律.当CaO含量为0.62wt％时,其纵向压电系数(d33)为120,介电常数(ε)可达820,较CaO含量为2.02wt％时,分别提高了84％和51％.随着CaO含量的增大,多孔PZT陶瓷的显微硬度明显提高,当CaO含量为2.02wt％时达到最大值0.98 GPa.     

利用陶瓷抛光废料制备MgO-SiO2-Al2O3系多孔陶瓷过滤材料的研究

以建筑陶瓷抛光废料为主要原料,通过正交试验优化配方和工艺条件,制备了MgO-SiO2-Al2O3系多孔陶瓷过滤材料,探讨了工艺参数,特别是烧成温度和保温时间对其物理性能的影响.研究结果表明,在配方组成为抛光废料50%、煅烧氧化铝22%、烧滑石28%和工艺参数为球磨时间25 min、成型压力70 Mpa、烧成温度1250 ℃、保温时间20 min的工艺条件下,可获得以堇青石和少量刚玉为主晶相的MgO-SiO2-Al2O3系多孔陶瓷过滤材料,其气孔率、断裂模数、吸水率和体积密度分别为70.06%、6.85 Mpa、85.25%和0.72 g/cm3.     

海藻酸钠凝胶法制备直通孔Al2O3陶瓷及负载BiOI光催化性能研究

多孔陶瓷具有耐腐蚀、耐高温、比表面积大等优异特性,在化工、催化剂载体、水处理方面具有广泛应用.本文采用海藻酸钠凝胶法制备了直通孔氧化铝多孔陶瓷,通过调控固相质量分数含量(10％,15％,20％,25％,30％)、海藻酸钠质量分数含量(1.5％,2％,2.5％,3％)、氯化钙浓度(1.5,2,2.5,3 mol/L)、烧...     

环氧树脂含量对激光选区烧结制备多孔煤系高岭土陶瓷性能的影响

目前,我国对煤系高岭土资源的整体深加工技术水平较低,导致了资源浪费和环境污染。本文分别以煅烧煤系高岭土和环氧树脂为原料和粘结剂,利用激光选区烧结工艺制备多孔煤系高岭土陶瓷,研究了环氧树脂含量对多孔煤系高岭土陶瓷性能的影响。研究表明,制备的多孔煤系高岭土陶瓷主要物相为莫来石和方石英,其孔隙分布均匀。随着环氧树脂质量分数从10%增大到25%,多孔煤系高岭土陶瓷素坯的抗弯强度由0.17 MPa增大到0.32 MPa,多孔煤系高岭土陶瓷的抗弯强度由2.81 MPa减小到0.82 MPa,其气孔率由50.37%增大到59.69%。以煤系高岭土为原料,采用激光选区烧结工艺制备多孔陶瓷对煤系高岭土资源的开发利用具有较为重要的意义。     

Thermogravimetric study for the co-combustion of coal and dried sewage sludge

The co-combustion of dried sewage sludge with coal is a promising method to dispose of and treat sewage sludge waste. Because sewage sludge has a different elemental composition than coal, the co-combustion of sewage sludge with coal may have different combustion characteristics than the single combustion of coal. In this study, the co-combustion of dried sewage sludge with coal was tested varying heating rates and mixing ratios of the dried sewage sludge. The results were analyzed using thermogravimetric (TG) and derivative thermogravimetric (DTG) curves and modeled using Ozawa-Flynn-Wall and Vyazovkin models. The mixed samples of coal and dried sewage sludge showed similar TG curves to the coal sample. The co-combustion showed activation energies close to that of the single coal combustion. This suggests that the co-combustion of coal and dried sewage sludge has similar combustion behavior to the single combustion of coal for mixing percentages of dried sewage sludge up to 20%.     

Application of sewage sludge in the manufacturing of ceramic tile bodies

The substitution of clayey raw materials urban sewage sludge in the production of traditional ceramics could give place to a cost saving due to the utilisation of wastes as secondary raw material. At the same time, it can help to solve the environmental problems associated to such wastes. This research shows the results of the substitution of clay for sewage sludge in different proportions in a ceramic body. The sludge characterisation has been carried out by an analytical protocol. After that, the most suitable products were selected regarding to the chemical composition and the technological characterisation of the resulting ceramic material.     

The use of sewage sludge and marble residues in the manufacture of ceramic tile bodies

The substitution of clayey raw materials for other wastes, in this case urban sewage sludge and marble sludge, in the production of traditional ceramics could be cost effective from the utilisation and recycling of these wastes as a secondary raw material. At the same time, it can be helpful in tempering the environmental problems associated with such wastes. This research shows the results of the addition of marble sludge and urban sewage sludge in different proportions to clay in a ceramic body. The most suitable products were selected regarding the mineralogical composition of the resulting ceramic material and its technological behaviour. To evaluate the ceramic properties of the obtained material, several processing and product properties (linear contraction, water absorption, bending strength) were determined. With regard to the technological properties of the final ceramic bodies, there does not seem to be any clear relation between the linear contraction values and the content of residue. However, the increase in water absorption along with the increase in the residue content is evident. The addition of residue decreased the bending strength. The selection of the adequate content of sludge to be added to the ceramic body will be controlled by the usual standards applied to construction materials.     

Preparation and performance of lightweight porous ceramics using metallurgical steel slag

In this paper, porous ceramics with high porosity and low bulk density were prepared by using steel slag and kaolin as main raw materials and polyurethane sponge as template. The effects of steel slag particle size, zirconia addition, the solid content of the slurry, and the addition of polycarboxylic acid water-reducing agent on the properties of ceramics were studied. In addition, by adding a surfactant (Sodium dodecyl sulfate) to form fine pores on the original framework of the three-dimensional network porous ceramic, the shortcomings of the single as well as the uncontrollable density and porosity of the porous ceramic, which are produced by the template method, are improved. When the grinding time of steel slag is 90 min, the content of zirconia is 3% wt, the solid content of ceramic slurry is 64% wt, and 0.6% wt polycarboxylic acid water-reducing agent and 0.4% of surfactant are added, the prepared porous ceramic skeleton is clear and good. The porous ceramic has a low bulk density (as low as 157.869 kg/m³), high porosity (about 94.05%) and high compressive strength (0.2 MPa). The crystalline phase of it is mainly composed of anorthite, gehlenite, forsterite and quartz. The addition of zirconia, water-reducing agent and surfactant only changes the macrostructure of porous ceramics, and does not change its crystal phase composition. The preparation of porous ceramics from steel slag not only solves the recycling problem of steel slag, but also provides a good substitute for main raw materials of porous ceramics.     

陶瓷抛光废料对多孔陶瓷砖气孔形成过程影响的研究

本文以陶瓷抛光废料为主要原料,研制了以石英和莫来石为主晶相的多孔陶瓷轻质砖,采用XRD、显微镜分析了陶瓷抛光砖废料对其气孔形成过程的影响,探讨了影响其气孔形成的主要因素。研究结果表明,陶瓷抛光砖废料由于含有机物和无机盐,可作为成孔剂,在400-700℃温度范围,有机物分解形成小气孔,随着温度的升高,以钙镁碳酸盐为主的无机盐在900℃左右分解,所形成的气孔由小变大;影响多孔陶瓷轻质砖气孔形成的主要因素是原料配方和烧成制度。     

污泥煤浆气化制氢工艺研究

介绍污水处理厂剩余污泥与煤制成污泥煤浆进行气化制氢的方法和流程,分析其经济性和可靠性。研究发现,污泥煤浆气化出口合成气有效气约为80%,冷煤气效率约为72%,合成气产出率约为86%。污泥煤浆制氢能耗约为20.5GJ/1000m3H2,污泥添加量每增加5%,单位制氢能耗增加1.5%。采用污泥煤浆制氢,主要原料成本约920元/1000m3H2,且随着污泥添加量的增加,制氢成本下降。采用污泥制氢能处理到非常难于处理的废弃物,具有很好的经济效益和环境效益。     

污泥与高硫煤共水热碳化过程中硫氮形态转化规律

采用高温高压反应釜进行了污泥(SS)和高硫煤(CS)的共水热碳化实验。分别考察了混合比和温度对水热炭中硫氮元素形态转化规律的影响。研究结果表明,经过水热处理后,SS中蛋白质氮(N-A)转化为杂环类氮,CS中吡咯氮(N-5)和吡啶氮氧化物(N-X)转化为吡啶氮(N-6)和季氮(N-Q);SS与CS中硫元素逐渐转化为噻吩硫和硫酸盐。随着CS混合比例和温度的升高,水热炭中含氮芳族杂环(例如N-6、N-5和N-Q)占比增加。另外,随着CS混合比例和温度升高,水热炭中噻吩硫含量分别逐渐增加至22.61%和24.98%;升高温度提高了水热炭中硫酸盐含量,而增加CS混合比例却降低了硫酸盐含量。本研究可为后续SS和CS的资源化清洁利用提供理论基础。     

高效混凝沉淀池的运行管理

介绍了枣庄市污水处理厂高效混凝沉淀池的工艺流程、设计参数,重点分析了进水量、凝聚和絮凝搅拌强度、药剂投加点和投加量、絮凝区污泥浓度和污泥回流量、污泥停留时间和污泥位等参数对处理效果的影响。通过总结生产实践经验,建议应控制进水量均匀稳定,凝聚搅拌强度控制在80~120 r/min,絮凝搅拌强度控制在15~20 r/min,PAM投加量为0.6 mg/L,除磷时Fe Cl3与磷的物质的量比为1.4,絮凝反应区污泥质量浓度控制在120~180 mg/L,沉淀区污泥位控制在1.0~1.8 m。     

Variability study of incinerated sewage sludge ash in relation to future use in ceramic brick manufacture

Abstract

The prospective use of incinerated sewage sludge ash (ISSA) as a partial replacement for traditional brick-making materials has been previously reported. However, variability in the consistency of the raw materials used in commercial brick manufacture can cause serious production problems. Consequently, to gain market confidence for ISSA in this role, it is essential to establish that its quality is not detrimentally affected either by the nature of the sewage sludge being burned, or as a result of the performance of the incineration process itself. Ash sampling was conducted at a large modern commercial sewage sludge incinerator over a six week period, followed by property characterisation and ceramic evaluation. The results confirm that this source of ISSA is satisfactorily consistent in quality over time, thus verifying its potential for use in brick manufacture on a commercial basis. Recommendations for additional research to help ensure widespread acceptance are also discussed.