粘土中铁含量对烧制轻质/超轻污泥陶粒的影响

以济南粘土,淄博某砖厂粘土和光大水务(济南)有限公司脱水污泥为原料,不添加任何膨胀剂烧制污泥陶粒。首先对两种粘土进行化学成分分析(EDX),矿物成分分析(XRD)和热重量分析(TGA);之后将粘土和污泥分别进行配比烧制试验,得到不同原料和配比所生产污泥陶粒的物理性质;最后对两种污泥陶粒进行矿物成分分析(XRD)和微观结构分析(SEM)。实验结果表明,济南粘土适合于烧制轻质污泥陶粒;淄博粘土更适合于烧制超轻污泥陶粒。两种粘土化学成分除含铁量外其它成分基本相似但矿物组成有所不同,并且污泥陶粒物理性质的变化随着污泥添加量的增大表现出明显不同的趋势。由于两种粘土中所含铁量的不同,生产的两种陶粒在矿物组成和微观结构上也有所差异。     

轻质/超轻粉煤灰陶粒的研制及陶粒膨胀机理的探讨和应用

以煤灰和粘土为原料制备轻质/超轻粉煤灰陶粒;从原料化学成分的角度推理膨胀过程并推导出可以用于指导实际生产的成分比例.首先对两种原料进行化学成分分析(EDX)和热分析(DSC/TGA);之后对原料进行配比烧制试验,得到不同原料和配比所生产粉煤灰陶粒的物理性质;最后对产品进行微观结构分析(SEM)和矿物组成分析(XRD).实验结果表明,粉煤灰中含有的成气成分和粘土中含有的助熔成分是引起粉煤灰陶粒高温膨胀的主要原因.产生膨胀现象的骨架成分:成气成分:助熔成分≈78.5:4.0:16.5.     

一种超轻陶粒及其制备方法的研究

本发明涉及一种超轻建筑陶粒,尤其是涉及一种采用精对苯二甲酸(Pure Terephthalic Acid,PTA)石化沉淀污泥、海泥、淤泥、废石粉等固体废渣为原料的超轻陶粒及其制备方法。     

污泥陶粒制备工艺烧结温度影响研究

为明确陶粒制备工艺的烧成温度范围,考察焙烧机制,进行了不同温度污泥烧制页岩陶粒的实验研究。结果表明,工艺控制参数耐火度:Al2O3/+SiO2Fe2O3+CaO+MgO+Na2O+K2O可以表征混合料烧成开始温度;1000℃以下烧制陶粒的孔径分布为单峰曲线,1050～1100℃烧制陶粒的孔径呈现双峰结构,焙烧机制对陶粒孔隙分布有如下影响:提高焙烧温度,峰值孔径增大,延长焙烧时间,峰值孔径相对位置增加;XRD分析表明,陶粒主要晶相为石英和蓝晶石,在1050℃以上烧结,孔分布出现双峰曲线,可能与氧化铁分解有关。     

自制粉煤灰陶粒填料处理城市污水

利用粉煤灰、黏土、脱水污泥和碳酸钙等原料制备粉煤灰陶粒。通过正交试验确定原料的最优配比,并对自制陶粒进行了性能表征,进一步利用自制曝气生物滤池装置,通过改变运行参数,测试了自制陶粒用作曝气生物滤池填料处理城市污水的效果。结果表明:自制陶粒填料各项性能都符合相关标准;化学需氧量(COD)、总氮(TN)去除率随着水力停留时间(HRT)的增加而增加,当HRT为4h时,总磷(TP)去除率达到最大;低温不利于TN、TP的去除,温度对COD去除率影响不大;当进水中的TN含量为30mg/L时,TN去除率最大。TP去除率随着进水中的TP含量的增加而增加,进水浓度对COD去除率影响不大。     

污水污泥页岩陶粒的烧成工艺与性能

为制定合理的污水污泥页岩陶粒烧成工艺及揭示污水污泥对陶粒性能的影响,研究了污水污泥掺量对陶粒烧胀性能的影响以及预热、焙烧的温度和时间等因素对陶粒性能的影响,采用扫描电镜观察了污水污泥和烧成工艺对陶粒结构的影响.结果显示,含水率80%左右的污水污泥掺量30%时,可获得表观密度700 kg/m3左右的轻质陶粒;适当降低预热温度、缩短预热时间、提高焙烧温度和延长焙烧时间有利于获得轻质污泥页岩陶粒.掺加污水污泥有利于页岩陶粒烧胀性能提高,但需要控制合适的烧成工艺.     

污泥填料制备实验研究

本文是以脱水污泥为骨料制备用于污水处理中生物膜载体填料,探索了以废制废、污泥资源化的新途径.实验使用脱水污泥为主要原料、粉煤灰和牯土为添加剂,得到制备填科最佳成分配比和最佳工艺条件是烧成温度为1000±25℃、污泥掺量为70%、保温时间为40min,填料的抗压强度达到25Mpa、吸水率17%,污泥填料处理药厂废水常温下CODCr的平均去除率为74.091、SS去除率为54.1%.结果表明,污泥作骨科,可以制备出性能优良的填料.     

焙烧温度对污泥陶粒烧胀过程及结构特征的影响

按质量比为m(污泥)∶m(盐渍土)∶m(蒙脱土)=75∶20∶5的配比,将料球分别烧至1000℃、1050℃、1100℃和1150℃,研究了焙烧温度对污泥陶粒烧胀过程和结构特征的影响。结果表明,1100℃时陶粒的主晶相是石英、蓝晶石和钙长石,1150℃时陶粒的主晶相是莫来石、石英和蓝晶石。莫来石是由蓝晶石转化而来,在高温时形成富硅铝和富钙的液相以及二液分相现象,最后生成莫来石、玻璃体和钙长石。陶粒烧胀的原因是在还原气氛下发生铁碳反应。陶粒内部形成玻璃体为主体,中间有莫来石增强相的结构,陶粒断面形成致密结构和均匀的封闭孔。     

纺织污泥对免烧陶粒的制备及性能影响研究

以纺织污泥为主要原料制备免烧陶粒.通过实验分析探究了污泥/水泥比、粉煤灰添加量和养护时间对陶粒性能的影响.结果表明:纺织污泥基免烧陶粒的最佳原料配比和养护工艺为污泥/水泥比为2.25,粉煤灰添加量为5％,粘结剂添加量为1％,养护时间为28天.该条件下制得的陶粒筒压强度为6.93 MPa,堆积密度为753kg/m3,1 ...     

钡改性污泥陶粒对废水中Cr(Ⅵ)的吸附性能研究

以污水厂污泥、粉煤灰为主要原料制备污泥陶粒,并采用BaCl2浸泡、焙烧的方法对其进行改性,制得钡改性污泥陶粒(Ba-SC),考察了其对水中Cr(Ⅵ)的吸附性能、动力学及吸附等温线,并采用扫描电子显微镜(SEM)对其进行了表征。结果表明:Ba-SC对Cr(Ⅵ)的去除效果远高于SC,且吸附效果受pH影响较大,在pH≥7时对Cr(Ⅵ)的去除率可达90%以上。SEM结果显示,负载在污泥陶粒表面的Ba可吸附Cr(Ⅵ)并与之反应形成正交晶型的结晶体。Ba-SC对Cr(Ⅵ)的吸附过程符合准二级动力学模型及Langmuir等温吸附模型,吸附反应为单分子层化学吸附过程。     

Glass-ceramic from sewage sludge ash

Glass-ceramic was produced by adding limestone to sewage sludge incinerated ash. Black glass was produced by melting a blended ash batch at 1450°C. For nucleation, this glass was reheated at 800°C for 1 h, and reheated at 1100°C for 2 h to form glass-ceramic. The main components of sewage sludge incinerated ash are SiO2 and Al2O3. Because small amounts of Fe2O3, sulfur and carbon are included, the addition of limestone alone can generate the crystal nucleant, FeS, to form anorthite (CaO·Al2O3·2SiO2) crystal. The glass-ceramic showed superior characteristics of high strength and acid resistance for use in construction materials. This revised version was published online in November 2006 with corrections to the Cover Date.     

掺加页岩与粉煤灰对污泥脱水性能的影响

改善污泥的脱水性能有利于污泥的处置与利用,以污泥建材资源化为目标,实验研究了在污泥沉降浓缩阶段加入页岩和粉煤灰后对沉降污泥脱水性能的影响。结果显示单掺页岩或粉煤灰后污泥的脱水性能得到显著改善;污泥比阻从处理前的1013数量级降至1011数量级;污泥脱水后的含水率降低,有利于后续的处理和利用;污泥脱水后的体积有一定程度增大,但这种体积增大在污泥的建材资源化利用方面是可接受的。混掺页岩和粉煤灰后对污泥脱水性能的改善效果优于单掺,页岩与粉煤灰掺量均为5%时,污泥的脱水性能得到最佳改善,且脱水污泥体积无明显增加。     

Investigation of sewage sludge stabilization potential by the addition of fly ash and lime

The aim of this work was the examination of stabilization potential of sewage sludge by the addition of fly ash and/or lime and the investigation of the effect of stabilization time on the properties of produced mixtures. Five samples were prepared by mixing fly ash, sewage sludge and lime in various ratios and the mixtures were stabilized for a period of 35 d. The addition of alkaline agents resulted in the increase of sample pH up to 12, the increase of total solids content to about 50% and the reduction of the organic fraction of the solids. The produced samples presented inhibition effects to seed germination and root length growth of three higher plants (one monocotyl and two dicotyls); however, samples with high sludge content resulted in negligible seed germination inhibition at prolonged stabilization times. The standard TCLP leaching procedure was applied in all the produced samples in order to evaluate the extraction potential of certain metallic elements; the content of metals in the eluates was varied, depending upon their speciation and form. Eluates presented significant inhibition to the marine photobacterium Vibrio fischeri bioluminescence, while the lowest inhibition was detected for the samples containing higher sludge content. These samples potentially could be applied as soil amendment, offering an efficient method for the combined utilization of two different solid wastes; however, low dosages of fly ash should be used for the production of a stabilized material presenting negligible effects with respect to its phytotoxic and ecotoxic properties.     

Microstructure and mineralogy of lightweight aggregates produced from washing aggregate sludge,fly ash and used motor oil

The microstructures and mineralogical compositions of lightweight aggregates (LWAs) manufactured with washing aggregate sludge (WS), fly ash (FA) and used motor oil (UMO) have been studied. Most LWAs with WS and FA exhibited an external layer and a glassy core with isolated pores. LWAs with WS and UMO did not present external shells or signs of bloating. Iron oxides, within the external layer, and pyrrhotite, in the inner glass, were observed. The mineralogical analyses revealed the neo-formation of plagioclase and pyroxene, along with minor gehlenite. Some relationships could be established: (i) the presence of larger pores is related to a decrease in the dry particle density values, (ii) when the LWA lacks the external layer, the water absorption values were dependent on the size and amount of each type of pore (open or closed), and (iii) the neo-formation of Ca-plagioclase and the consumption of quartz improved the compressive strength values.     

Preparation of Β-sialon from thermal-plant fly ash

Carbon reduction of fly ash from the Reftinskaya thermal plant was studied at temperatures from 1100 to 1600‡C in a nitrogen atmosphere. The ash was analyzed chemically and by x-ray diffraction. Β-Sialon phases with compositions Si₃Al₃O₃N₅ and Si₂Al₃O₇N were obtained by ash reduction. Conditions for the preparation of Si₃Al₃O₃N₅ were optimized.     

Sintering effect on cement bonded sewage sludge ash

Through foaming reaction, hydration reaction and pozzolanic effect, sewage sludge ash (SSA) was used as main material to produce a sewage sludge ash foamed lightweight material (SSAFLM). Firing tests were conducted at different temperatures. This was to study how the use of sewage sludge ash (SSA) improved the thermal properties and sintering effects of cement-base materials, and to evaluate the feasibility of using SSA to improve the soundness of cement-base materials under high temperature. The experimental results revealed that when the sintering temperature was lower than 600 °C, the engineering properties and microstructure of SSAFLM were mainly affected by dewatering and hydrates decomposition. However, when the temperature was over 600 °C, the results were chiefly affected by sintering effects. At high temperatures, the more SSA was used, less crack formation resulted. Moreover, after fired at 1093 °C for 4 h, the compressive strength was improved by 44%, and the total pore volume decreased by 30% in average.     

Controlled low-strength material using fly ash and AMD sludge

Controlled low-strength material (CLSM) is a cementitious material with properties similar to stabilized soil. After hardening, CLSM provides adequate strength in bearing capacity and support but can also be easily excavated. To be classified as a CLSM, the material must have a compressive strength between 450 kPa (65 psi) and 8400 kPa (1200 psi). Typical CLSM contains coal-combustion fly ash (FA), cement, water and fine or coarse aggregate. In this paper, physical and strength properties of CLSM formed by combining sludge, a by-product from the treatment of acid mine drainage (AMD), with Class F FA are investigated. The sludge is a lime-based waste product that when combined with FA, exhibits self-hardening characteristics similar to cement. A main focus of this research is to develop a CLSM mix in which by-product material utilization is maximized while satisfying workability and performance requirements. A mixture of 10% AMD sludge, 2.5% Portland cement (PC), 87.5% Class F FA (dry wt.%) with water provided unconfined compressive strength values within the range for classification as CLSM. This mixture satisfies the excavatability and walkability requirements as well as the hardening time and stability criteria.     

Study on use of MSWI fly ash in ceramic tile

In this work, MSWI (municipal solid waste incineration) fly ash is used as a blending in production of ceramic tile by taking advantage of its high contents of SiO(2), Al(2)O(3) and CaO. Besides, macro-performance and microstructure of the product as well as its leaching toxicity in practical application were studied by means of XRD, IR and SEM analysis, and leaching toxicity and sequential chemical extraction analysis of the product. It is found that when 20% fly ash is added, the product registers a high compressive strength of 18.6MPa/cm(2) and a low water absorption of 7.4% after being sintered at 960 degrees C. It is found that the glazed tile shows excellent resistance against leaching, in accordance with HVEP stand, of heavy metals with Cd<0.0002ppm, Pb<0.0113ppm and Zn<0.0749ppm, and Hg below the low detection limit. These results show that heavy metals are cemented among the solid lattice in the product and can hardly be extracted. Leaching toxicity of heavy metals in the product, especially Hg, Pb, Zn and Cd, is substantially reduced to less than one-tenth of that in fly ash. In addition, specifications of Hg, Pb, Zn and Cd are largely changed and only a small portion of these heavy metals exists in soluble phases. These results as a whole suggest that the use of MSWI fly ash in ceramic tile constitutes a potential means of adding value.