含竹炭黄金尾矿陶瓷砖制备研究

采用黄金尾矿、紫金土为主要原料,添加不同配比的竹炭,通过干压成型-高温烧成法制备含竹炭黄金尾矿陶瓷砖,分析了竹炭添加量与烧成温度对陶瓷砖的物化性能、物相组成及显微结构的影响规律.研究结果表明,黄金尾矿、紫金土和竹炭的复合可以制备强度较高、吸水率较低的陶瓷砖,其物相主要为石英,显微结构呈规则网络状;在竹炭/黄金尾矿质量比为5/70,烧成温度为1125℃时,陶瓷砖具有较好的综合性能,其破坏强度可达528.9N,吸水率0.04%,达到GB/T4100-2006<陶质砖>附录L中对BⅢ类陶质砖破坏强度的要求,有望成为一种新型的环境友好型陶瓷砖.     

钼尾矿制备高保水蓄水材料

以钼尾矿为原料,采用化学发泡法成型并烧结制备了海绵城市用无机蓄水材料,研究了钼尾矿掺量对蓄水材料吸水率、体积密度、抗压强度及保水率的影响。通过XRD和SEM分析了样品的物相组成和微观形貌。结果表明:随着钼尾矿掺量的增加,蓄水材料的抗压强度逐渐降低;保水率先增大后减小,钼尾矿掺量为50%时达到最大。最佳工艺参数为:钼尾矿掺量50%,发泡剂用量0.5%,烧成温度1050℃,此工艺条件下所制蓄水材料的吸水率为52.56%,体积密度为0.65 g/cm3,抗压强度为1.25MPa,保水率为75.10%。     

粉煤灰页岩烧结制品的微孔造孔技术研究

以粉煤灰和页岩为主要原材料,通过对试件烧成收缩、抗压强度、体积密度、显气孔率、导热系数等的分析,研究了内燃型、热分解型、热致收缩型、复合型4类9种造孔剂对烧结制品性能的影响。结果表明:内燃型造孔剂M的掺加降低了试件的烧成收缩,随着M掺量增加,试件显气孔率升高、体积密度降低;热分解型造孔剂D和热致收缩型造孔剂Z可以有效的控制试件的烧成收缩,降低体积密度,并增加显气孔率和吸水率;复合掺加M、Z两种造孔剂后试件尺寸收缩和质量损失稍有增加,显气孔率和吸水率略有降低;微孔造孔技术可增加显气孔率,降低体积密度和导热系数,改善烧结制品的热工性能。     

镍铁渣和锡尾矿共掺制备陶瓷砖的研究

废弃矿渣已经成为社会发展的一大阻力和环境污染的源头之一,资源化利用镍铁渣和锡尾矿,提高废弃物的利用价值。本文利用镍铁渣和锡尾矿共掺制备陶瓷砖,研究在不同温度下烧结对陶瓷砖性能的影响,采用XRD和SEM分析陶瓷砖的结晶相和微观结构。结果表明,在1320℃下烧结的陶瓷砖(镍铁渣30%+锡尾矿30%)吸水率小于0.5%,破坏强度大于2500N,符合国家标准。实验发现,镍铁渣由于含有大量的MgO,导致烧结温度较高,掺比量不宜大于35%。镍铁渣和锡尾矿的共掺量达到60%,可以有效地解决镍铁渣和锡尾矿的堆积问题。     

粉煤灰掺量及聚丙烯纤维对泡沫混凝土性能的影响

以容重等级600kg/m3的泡沫混凝土为基础,研究粉煤灰及聚丙烯纤维掺量对泡沫混凝土性能的影响,结果表明,粉煤灰掺量为30%时泡沫混凝土的各项综合性能最佳:质量吸水率较低为21.89%、气孔率最低为71.43%、强度较高为2.3MPa。具有质轻、高强、弹性好等优点的聚丙烯纤维掺入后,泡沫混凝土的各项性能均有良好的改善。     

粉煤灰/赤泥基发泡陶瓷保温材料的制备及性能研究

以粉煤灰、赤泥为主要原料,硼砂为助熔剂,外掺CaCO₃发泡剂,采用粉末烧结工艺方法,通过原料粉磨预处理、原料混合、压制成型、烧结等工序制备了粉煤灰/赤泥基发泡陶瓷保温材料;研究了烧成温度、保温时间、发泡剂掺量对保温材料平均孔径、气孔率、表观密度、抗折强度等性能指标的影响,并分析其影响机理。结果表明,在粉煤灰占比35%、赤泥占比35%、助熔剂硼砂占比30%条件下,CaCO₃发泡剂外掺量为5%、烧成温度为690℃、保温时间为30min烧成的发泡陶瓷保温材料的性能最优,其气孔率为64.23%,密度为286kg/m³,抗折强度为1.492MPa,平均孔径为3.0mm。     

利用赤泥制备陶瓷保温砖的研究

本研究利用两种赤泥成功地制备了具有保温功能的陶瓷砖.其中烧结法赤泥和拜尔法赤泥的总掺量在60wt%以上,制备的样品具有较高的抗压和抗折强度及较低的导热系数.利用XRD、SEM等测试手段分析了样品的理化性能与微观结构.结果表明:烧结法赤泥添加量为24%,拜尔法赤泥添加量为36%时,样品的最佳烧成温度为1040℃,气孔率为41.57%,吸水率23.13%,体积密度为1.80g/cm3,抗折强度为14.97MPa,抗压强度53.84MPa,导热系数为0.88w·m-1·K-1.样品的主晶相组成为SiO2、Fe2O3、Ca3Fe2Si3O12、Ca2Al2SiO7、CaMgSi2O6.     

粉煤灰基轻质泡沫材料的制备与性能研究

以粉煤灰为原料,通过造孔剂发泡法和浆料发泡法制备了新型轻质泡沫材料,确定了其最佳制备工艺条件.考察了浆料发泡法制备过程中碱激发和泡沫掺量对泡沫材料结构和性能的影响,通过调节泡沫掺量和坯体烧结温度,材料的显气孔率、密度、吸水率、抗压强度分别达到62.74％、0.50 g/cm3、126.50％、6.76 MPa.     

影响粉煤灰泡沫玻璃保温隔热性能的试验研究

本文针对影响粉煤灰泡沫玻璃物理性质的4个主要因素:发泡剂掺量、粉煤灰掺量、发泡温度和发泡时间,设计安排正交实验,并对制品的各项性能指标进行测试。以导热系数、表观密度、吸水率、强度为主要考核指标,采用极差分析的方法对实验数据进行处理分析,得出制备粉煤灰泡沫玻璃的最佳参数。研究结果表明:1)粉煤灰掺量对粉煤灰泡沫玻璃外墙保温材料各个物理指标的平均影响程度最大,发泡剂对材料的导热系数和吸水率影响较大;2)发泡温度对粉煤灰泡沫玻璃各项物理性能的影响程度最小,发泡时间对材料的强度影响相对较大;3)材料的制备过程中影响材料性能的主导因素是原料配比,而焙烧制度则为次要因素;4)通过最佳实验制备参数制得的粉煤灰泡沫玻璃导热系数可达到0.07 W/(m·K)以下,表观密度低于300 kg/m3,具有良好的保温隔热性能。     

利用铁尾矿粉制备保温砌块的研究

以水泥、铁尾矿粉、粉煤灰、硅灰为主要原料,双氧水为发泡剂,聚丙烯纤维为增强材料,辅以硬脂酸钙为助剂,制备泡沫混凝土砌块。通过分析粉煤灰、铁尾矿粉、硅灰、聚丙烯纤维、硬质酸钙掺量对泡沫混凝土砌块性能的影响研究,结果表明:配合比为铁尾矿粉掺量12%、粉煤灰掺量15%、硅灰掺量2.4%、纤维掺量0.2%、硬脂酸钙掺量0.8%,水胶比0.48,可制备出密度等级为600Kg/m3的泡沫混凝土砌块。     

改性瓷砖胶粘剂的配制与性能

为了改善传统瓷砖胶粘剂技术的种种弊端,通过在普通水泥砂浆中复掺少量聚合物干粉和较大掺量粉煤灰的方法,配制出施工和易性好、粘结强度高和耐久性优良的新型瓷砖胶粘剂。     

Utilization of a very high lime fly ash for improvement of Izmir clay

This paper presents an investigation into the stabilization of a soft clay subgrade of a military zone in Izmir, Turkey with a very high lime fly ash. Zero%, 5%, 10%, 15% and 20% (m/m) of the soil was replaced with fly ash. In addition to the control specimen, four different stabilized soil samples were prepared mixing fly ash with soil at optimum water contents determined by standard proctor test. Experiments lasted for 3 months and the unconfined compressive strength and shear strength parameters, cohesion and internal friction angle, were determined after 1, 7, 28 and 90 days. It was found that, inclusion of fly ash improved the properties of the soil. The improvements, appearing with increasing fly-ash content, were attributed to the pozzolanic reaction and pore refinement effect of fly ash as well as its high free-lime content.     

硅藻土/竹炭复合材料的制备及孔结构表征

本研究以竹炭为主要原料,添加硅藻土,以硅铝复合物为粘结剂,经粘结造粒、表面包覆改性、高温煅烧等工艺,制备了一种新型硅藻土/竹炭复合材料。采用氮吸附法对其孔结构进行表征,结果表明,BET比表面积为142.563m2/g,总孔容为0.156cm3/g,相比竹炭,比表面积有所降低,但总孔容却提高了43.12%,意味着吸附容量增大了;孔隙分布也较合理,微孔率、介孔率和大孔率分别为44.23%、32.05%和23.72%,克服了硅藻土和竹炭孔径分布过窄的缺点。由此表明在竹炭中添加硅藻土制备介孔率高、孔径分布均匀、吸附容量大的吸附材料是一种可行的方法。     

粉煤灰和抛光渣抑制碱硅酸反应及其机理研究

采用砂浆棒快速法,分别以0%、20%、30%、40%的粉煤灰和抛光渣等质量取代水泥制备砂浆试件,进行膨胀率及强度测试,借助扫描电镜(SEM)、能谱分析(EDS)和X射线衍射(XRD)等方法对碱环境下集料与胶凝材料界面过渡区的微观结构、元素组成和生成物进行分析,研究粉煤灰和抛光渣抑制碱硅酸反应(ASR)的内在机理.结果表明:粉煤灰和抛光渣均可有效抑制ASR,综合考虑粉煤灰、抛光渣对ASR的抑制作用和对材料强度的影响,粉煤灰、抛光渣取代率宜取20%～30%;掺粉煤灰和抛光渣均可使界面过渡区结构更致密;界面过渡区钙硅比和钠硅比明显降低;钾硅比和铝硅比在界面过渡区有突变,K和Al在界面过渡区富集,原因为K~+比Na~+更倾向于与Al_2O_3结合.尽管抛光渣碱含量较高,但其中高含量的SiO_2、Al_2O_3及活性集料中的SiO_2可与体系中的Na~+、K~+共同作用,在界面过渡区生成体积稳定的架状结构硅酸盐矿物钾霞石KAlSiO_4和霞石(K,Na)AlSiO_4,从而抑制ASR.     

粉煤灰对高性能混凝土强度的影响

探讨了粉煤灰在高性能混凝土中的活性效应及作用机理。通过试验研究得出,当水胶比为０．３５以下时,在水泥砂浆中掺入３０％粉煤灰,其强度比可达到０．９５以上;在混凝土中掺入５０％粉煤灰,其抗压强度可达到６０ＭＰａ以上,可见粉煤灰在高性能混凝土中能发挥较好的活性效应。     

Adsorption of mercury(II) by coal fly ash

Coal fly ash, an industrial solid waste, was found to have a good adsorption capacity for mercury(II). Adsorption of mercury(II) on coal fly ash conforms to Freundlich's adsorption model. Several parameters such as time of equilibration, effect of pH, effect of initial concentration of solute, effect of fly ash dose etc. were studied. The maximum adsorption was observed after shaking for 3 h. Solution pH was the most important parameter affecting the adsorption. The optimum pH range was 3.5–4.5. There was total adsorption of mercury below 10 mg l⁻¹. The performance of coal fly ash as an adsorbent was found to be significant when compared with activated powdered charcoal.     

粉煤灰对砂浆性能影响的研究

在砂浆中加入粉煤灰,不但能降低砂浆的成本,而且还能够改善砂浆的施工性能、提高砂浆保温性能。在满足加气混凝土(泡沫混凝土)抹面砂浆粘结强度高、收缩率低的前提下,粉煤灰掺量30%时,所配制的砂浆导热系数为0.1953W/m.K,与加气混凝土(泡沫混凝土)砌块导热系数接近,具有良好的保温效果。     

粉煤灰超高强高性能混凝土配制

采用比表面积为１４０００ｃｍ２／ｇ的超细磨粉煤灰和高效减水剂配制出坍落度２４３ｍｍ,２８ｄ抗压强度１０８．５５ＭＰａ,１８０ｄ抗压强度１４０．４ＭＰａ的超高强高性能混凝土。对用原状粉煤灰、硅灰、超细磨粉煤灰分别作混凝土的掺合料进行了性能对比,指出超细磨粉煤灰既有粉煤灰本身的“滚珠轴承”润滑作用和火山灰反应增强作用,又有硅灰的填隙挤水和密实增强作用。     

The concentrations and particle size relationships of selected trace elements in fly ashes from U.K. coal-fired power plants and a refuse incinerator

Fly ash samples from 11 coal-fired power plants and a refuse incinerator in the U.K. were analyzed for total arsenic, cadmium, lead and selenium. Enrichment factor (EF) values calculated with respect to crustal abundance (EF_crust) were highest for cadmium and lead in refuse fly ash, with EFs of 2500 and 740, respectively. Enrichment factors for selenium were similar in both fly ash types; only arsenic was more enriched in coal fly ash compared with refuse fly ash. Despite the high EF_crust values of certain elements in the two fly ash types, the same elements showed EF values of about unity when expressed with respect to the starting material. Both materials displayed an inverse relationship between particle size and extent of enrichment for all the elements studied, but the degree of enrichment on the finest particles was lower than reported for coal fly ash by other workers. The EF_crust values estimated for arsenic, lead and selenium in suspended particulates from a refuse incinerator were similar to those calculated for the urban atmospheric aerosol, whereas cadmium was 10 times more enriched in the suspended particulates.Scanning electron microscopy revealed a marked contrast in the morphological features of the two fly ash types. Coal fly ash was almost entirely composed of cenospheres of < 20 μm diameter, whereas refuse fly ash consisted mostly of amorphous particles of < 50 μm diameter; some cenospheres were, however, noted in the refuse fly ash.