应用电厂低品位过热蒸气制备超细粉煤灰

为了提高电厂热能综合利用率,实验采用自行研制的蒸气气流粉碎系统,研究热电厂低品位蒸气能向高品位能——机械能的能量转化机制。结果表明:自行研制的试验系统成功运用超音速喷嘴技术使电厂低品位蒸气获得巨大的动能,并将获得巨大动能的过热蒸气用于高效制备超细粉煤灰,获得的超细粉煤灰具有良好粒径分布和形貌特征,制备超细粉煤灰粒度分布均匀,d50=3.655μm,d90=8.000μm,并且有效保护粉煤灰中的玻璃微珠,符合粉煤灰资源化利用的要求。     

带立式涡轮分级机流化床在用电厂超细粉煤灰加工中的应用

随着我国工业建设与经济建设的快速发展，对电力的需求逐渐增加，发电厂的建设量较大。在这种情况下，电厂粉煤灰的排放量越来越多，进而对经济发展造成影响，同时破坏了土地与环境资源。因此，合理、综合利用粉煤灰成为电力企业发展的重要问题，是解决资源缺乏与环境污染之间矛盾的重要方式。本文主要介绍带立式涡轮分级机流化床，分析其在电厂超细粉煤灰加工中的应用，为电厂排放粉煤灰的利用提供参考。     

再生细骨料和超细粉煤灰增强UHPC的力学性能研究

为研究超细粉煤灰和再生细骨料对超高性能混凝土（UHPC）性能的影响,通过工作性能、轴心抗压、轴心抗拉和电镜扫描试验研究了超细粉煤灰和再生细骨料对UHPC抗压强度、抗拉强度和微观结构的影响规律,并建立了基于超细粉煤灰和再生细骨料影响的UHPC强度预测模型。结果表明：增加超细粉煤灰掺量,UHPC扩展度增加流动性较好,掺量不超过10%可改善UHPC抗压强度,达到115.36 MPa,超过后抗压强度有所降低,抗拉强度呈现上升趋势;再生细骨料掺量增加UHPC工作性能变差,但抗压强度及抗拉强度逐渐升高;电镜扫描试验发现粉煤灰消耗Ca（OH）₂产生更多C-H-S凝胶使得结构内部更加密集。基于改进的可压缩堆积理论模型,建立了超细粉煤灰改性再生细骨料UHPC强度预测模型。     

大掺量粉煤灰高性能混凝土的试验研究

本文探讨了中等强度大掺量粉煤灰高性能混凝土的工怍性、力学性能及耐久性。在大量试验的基础上,对不同掺量粉煤灰高性能混凝土的坍落度损失,抗压强度、干缩以及耐久性等性能进行了全面的分析。研究表明,它在道路工程、大体积工程及房建工程等方面有着广阔的应用前景。     

重质碳酸钙在超细粉碎中的多维分形特征

为了研究重质碳酸钙颗粒在超细粉碎过程中的分形维数以及多维分形特征与研磨时间的关系,对重质碳酸钙颗粒进行湿法研磨,提取不同研磨时间的颗粒,测量其粒度分布,并利用单一分形法和多维分形法计算样品的分形维数,建立分形维数与研磨时间的拟合曲线。结果表明:相对于单一分形法,多维分形法更能准确地描述颗粒的尺寸分布状态;通过分形维数与研磨时间拟合曲线中的峰值,可以判断颗粒的最佳研磨时间范围,这与实验中重质碳酸钙颗粒样品的最佳研磨时间60 min相符,从而优化颗粒超细粉碎过程中的研磨时间参数,减少能源消耗。     

木材断裂解离分形特征与分形断裂力学模型研究

目的 以椴木为研究对象,研究冲击载荷作用下椴木试件的断裂解离形貌特征和断裂力学特性,建立适用于木材原料断裂解离的分形断裂力学模型,并对其断裂解离力学行为进行描述。方法 对椴木试件进行冲击加载试验,分析试件断口的形貌特征和断裂力学特性,构建适用于木材原料断裂解离的分形断裂力学模型。结果 椴木试件横向冲击断裂断口裂纹形状和断口形貌特征比纵向冲击复杂,横、纵向冲击断裂断口均具有分形特征;椴木试件纵向冲击断裂韧性均值是横向冲击断裂韧性均值的1.112倍,椴木试件横、纵向冲击断口的分形维数均值分别为2.063 5和2.075 1,椴木试件横、纵向冲击韧性与其断口分形维数之间存在线性正相关关系,拟合优度分别为0.778 7和0.812 2;构建的木材原料断裂解离临界解离应力和断裂韧性的分形断裂力学模型也适用于脆性材料。结论 在木材原料冲击断裂解离时,木材原料初始裂纹长度越短,断裂解离断口越粗糙复杂,木材原料断裂解离所需要的能量越大;当裂纹沿着与冲击加载力方向垂直成大约1.055rad方向扩展时所需的能量最小,木材原料最易沿该方向进行断裂解离。     

废玻璃粉活性特征和活性机理研究

为了研究废玻璃粉的活性特征和机理,将无色、绿色和棕色废玻璃瓶研磨制成具有不同比表面积的4种粉料,等质量取代部分水泥制作胶砂试件,测定6个龄期的强度活性指数,并采用扫描电子显微镜、X射线衍射和净浆孔溶液p H分析废玻璃粉火山灰活性机理。结果表明:废玻璃粉的强度活性指数随着比表面积的增大而增大,两者之间具有良好的线性关系;废玻璃粉的强度活性指数随着龄期的增加而增大,并且与颜色相关;比表面积相近时,废玻璃粉的强度活性指数在28 d前小于粉煤灰的,28 d及以后接近甚至大于粉煤灰的。     

ABS塑料断面形貌特征及分形分析

分析测字了ＡＢＳ塑料冲击断面的形貌特征及对应的分形维数值，结果表明，不同断面表貌特征所对应的分形维数测量值不同，ＡＢＳ无缺口冲强度随满足自相似原理的形貌特征对应的分形维数测量值增大而线性增高，不满足自相似原理的形貌特征所对应的分形维数测量值量宏观冲击强度间无明显关系，但其大小仍合理表征了相应尺度范围内的形貌的特征变化。     

粉煤灰涂层材料的控释水特性

提出了一种新型涂层导水纤维的制备方法.用粉煤灰和有机溶剂溶解的EVA混合做涂层材料,选用与膜材成分相同的聚乙烯纤维作为预涂层纤维基体.用比表面积分析仪表征粉煤灰的孔径分布,在环境扫描电子显微镜下观察纤维表面微观真实形貌,用快速水分测定仪测试纤维在不同温度下的连续失水情况.改变土壤的相对含水量,测定了优选配比涂层纤维的失水.结果表明:EVA含量最少的纤维涂层渗水效果最好,涂层纤维的保水功能是由于粉煤灰的多孔产生了毛细孔凝聚现象,该涂层导水纤维对温度以及土壤湿度都具有自调节功能.     

矸石电厂粉煤灰基膏体充填材料研究

以矸石电厂粉煤灰为研究对象,通过化学分析、X射线衍射分析、扫描电镜等分析其理化特征的基础上,采用正交试验研究了以活化的矸石电厂粉煤灰为主要原料的膏体充填材料的输送性能和强度特性,并采用扫描电镜对膏体充填材料在不同龄期下的微观结构进行了表征与分析.研究结果表明,灰胶比达到3∶1的充填材料料浆初始坍落度为200 mm,粘聚性和保水性好,静置泌水率3%,初凝时间大于5 h,符合泵送要求.充填材料脱模后的试件8 h能够自稳,3 d和28 d强度为1 MPa和10 MPa左右,满足采空区充填要求.采用活化的矸石电厂粉煤灰制备的膏体充填材料成本低、环保,能为矿区带来经济、社会和环境等效益.     

Laboratory compaction of fly ash and fly ash with cement additions

The use of power-industry wastes as a material for earthen structures depends on its compactibility. It has been confirmed that a fly ash/bottom ash mix compacted several times in Proctor's moulds are not representative. The relationship between dry density of solid particles and water content for re-used waste samples was determined. The re-compaction effect on grain-size distribution, density of solid particles, specific surface and sand equivalent of wastes was investigated. Tests were conducted on fly ash samples compacted by the Standard and Modified Proctor methods. Another aim of the paper was to investigate the influence of cement additions on the compactibility of a fly ash/bottom ash mix. Waste samples in the natural state and with different percentages of cement additions (2, 5 and 10%) were compacted by both impact compaction methods to obtain compactibility curves rhod(w). It was found that cement addition resulted in an increased rhod max value, while wopt decreased. Linear regression relationships for changes in compaction parameters after cement stabilisation are also given.     

Effect of curing method on characteristics of cold bonded fly ash aggregates

This paper discusses the influence of normal water curing, autoclaving and steam curing on the properties of a typical class-C fly ash aggregate. The 10% fines value, water absorption, and porosity of aggregates are correlated with SEM and XRD results to understand the influence of various factors and material characteristics. An increase in duration of normal water curing significantly improved the aggregate properties. Autoclaving and steam curing resulted in relatively lower enhancement in the properties as compared to normal water cured aggregate. Between the accelerated curing methods, autoclaved aggregate possessed properties closer to the normal water cured aggregate due to the dense microstructure formation. Continuation of normal water curing, after initially subjecting the aggregates to accelerated curing, exhibited only a marginal improvement in the properties.     

原生粉煤灰涂层导水纤维的制备及其渗水特性试验研究

利用粉煤灰和有机溶剂溶解的EVA混合在聚乙烯纤维基体上涂层,制备新型涂层导水纤维.试验采用比表面积分析仪、环境扫描电子显微镜、快速水分测定仪分别对纤维涂层形貌以及渗水特性进行表征.试验结果表明:在筛选后的比例中,EVA 含量最少的纤维涂层渗水效果最好;该涂层导水纤维对温度以及土壤湿度都具有自调节功能.     

改性粉煤灰作橡胶填料的研究

以鸡西发电厂粉煤灰为原料对粉煤灰进行表面改性。从表面改性剂、粉煤灰的粒度、粉煤灰的填加量等几个方面的因素，来探讨改性粉煤灰对橡胶补强性能的影响。实验表明，表面改性后的粉煤灰对橡胶具有较好的补强作用，可替代部分炭黑，可以减少碳黑的用量，降低橡胶的成本，并减少粉煤灰对环境的污染。     

Compressive strength and microstructural characteristics of class C fly ash geopolymer

Geopolymers prepared from a class C fly ash (CFA) and a mixed alkali activator of sodium hydroxide and sodium silicate solution were investigated. A high compressive strength was obtained when the modulus of the activator viz., molar ratio of SiO₂/Na₂O was 1.5, and the proper content of this activator as evaluated by the mass proportion of Na₂O to CFA was 10%. The compressive strength of these samples was 63.4 MPa when they were cured at 75 °C for 8 h followed by curing at 23 °C for 28 d. In FTIR spectroscopy, the main peaks at 1036 and 1400 cm^?1 have been attributed to asymmetric stretching of Al–O/Si–O bonds, while those at 747 cm^?1 are due to the Si–O–Si/Si–O–Al bending band. The main geopolymeric gel and calcium silicate hydrate (C–S–H) gel co-exist and bond some remaining unreacted CFA spheres as observed in XRD and SEM–EXDA. The presence of gismondine (zeolite) was also observed in the XRD pattern.     

白云石／粉煤灰纤维的制备及性能研究

利用ACC-Ⅱ高温坩埚电阻炉将一定量的白云石与粉煤灰相混合，经高温熔化、拉丝等工艺进行制备白云石／粉煤灰纤维，通过扫描电镜（SEM）对其结构、形貌和特性进行研究，并讨论白云石含量对粉煤灰纤维性能的影响。结果表明，22％～28％（质量分数）的白云石和粉煤灰混合在高温熔化下，可形成新网状结构的硅酸盐功能材料。并且白云石能够改变粉煤灰纤维的结构、化学组成及性质，使粉煤灰纤维的化学耐久性、柔韧性和耐热强度等方面都有显著提高。     

Mechanical characteristics of clay structural ceramics containing coal fly ash

In this work, the mechanical characterization of ceramic products processed from red clay with different amounts of added coal fly ash was investigated. Coal fly ash produced by power plants is a waste material that constitutes an alternative source of minerals for the production of traditional building ceramics, as it is a complex mixture of several oxides such as SiO₂, Al₂O₃, CaO, Fe₂O₃, Na₂O, TiO₂, which are usually present in the composition of such ceramics. A powder technology and firing route was followed for the processing of the clay and coal fly ash based ceramics. Different proportions of waste (10, 25 and 50%, by weight) were added to red clay, and then the mixed powders were pressed to form compacts that were fired at a selected temperature in the range 850–1,150°C. The effects of waste content and of heating conditions on the microstructure and mechanical characteristics of the obtained materials were investigated. The density, porosity, water absorption, flexural strength, hardness and fracture toughness of the produced materials were evaluated. A comparison was made between the properties of the produced ceramics with those of traditional ceramic materials used in construction, e.g. floor or wall tiles, and it was observed that the clay based products with coal fly ash additions may be used in similar applications.     

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.