粉煤灰颗粒的微观分类探讨

鉴于目前关于粉煤灰颗粒的微观分类没有一个普遍、清晰、浅显的分类方法,且术语不够统一的情况,为方便学术交流提出了一个新的较普遍、清晰、浅显的原状粉煤灰颗粒分类方法,使粉煤灰颗粒微观分类方法更加完善。     

基于人工神经网络的粉煤灰科学分类

鉴于目前国内在粉煤灰分类方面存在的片面性,我们结合人工神经网络(ANN)理论,提出了基于人工神经网络的粉煤灰科学分类方法。该方法充分考虑了粉煤灰的火山灰活性,并考虑了细度、玻璃体、烧失量、K2O、SO3、CaO多种因素对分类的影响。实例表明,按本文提出的方法建立的网络模型比较合理,精度比较高,克服了以往分类方法的片面性,能比较全面地反映粉煤灰的品质性能,为粉煤灰的多元化利用提供依据。     

模糊聚类循环迭代模型及其在粉煤灰分类中的应用

根据模糊聚类基本原理 ,运用模糊聚类循环迭代模型研究了粉煤灰的分类问题。选择对粉煤灰分类影响较大的化学成分和物理性质为特征指标 ,以活性特性为目标 ,通过循环迭代计算获得科学的分类结果。研究表明该模型克服了以往传统分类法的不足 ,较全面地反映了产品的性能 ,从而为粉煤灰综合利用的优化配置奠定了基础。     

遗传投影寻踪评价方法的算法实现及其在粉煤灰分类中的应用研究

针对目前粉煤灰分类研究存在的片面性,在分析影响粉煤灰品质有关的化学成分和物理性质的基础上．选择细度、玻璃体、烧失量、K2O、SO3和CaO作为投影寻踪聚类分析的特征指标,以活性特征为目标,建立了投影寻踪聚类分析模型,编制了基于MATLAB的相应程序,采用遗传算法寻求最优投影方向,根据投影特征指标值对粉煤灰进行分类。研究表明该模型克服了以往传统分类法的不足,能较全面地反映粉煤灰产品品质性能。     

粉煤灰和煤矸石合成沸石分子筛的研究进展

简述了粉煤灰和煤矸石的组成、分类、性质和制取分子筛的方法。指出了应加强煤矸石分类的研究,从而指导煤矸石的利用。生产分子筛是粉煤灰和煤矸石的高附加值化工利用的有效途径之一,粉煤灰水热合成分子筛研究较多,但是反应时间太长,微波辅助合成分子筛可以加快粉煤灰中的硅和铝溶解,从而降低活化时间,但需要解决微波合成分子筛的工程放大问题。     

粉煤灰颗粒分级试验及混凝土应用技术的研究

本文介绍了湿排粉煤灰颗粒分级试验和粉煤灰质量评定方法，对粉煤灰的基本性质及分类方法作了探讨；重点叙述了粉煤灰砼应用的一些技术性问题     

粉煤灰特性对混凝土性能的影响

粉煤灰的化学成分对其物理性质或化学性质的影响，还有待于进一步深入研究，但化学成分有明显差别的粉煤灰，其性质也有显著差异，这是肯定的。近几年为三峡工程选择粉煤灰，使我们得以在较大范围内对粉煤灰进行调查，从而发现，我国的粉煤灰按其化学成分分类，大致可分为：①低钙灰，氧化钙含量在5％～     

贝叶斯（Bayes）判别分析在粉煤灰分类中的应用

论述了多元统计方法中的贝叶斯判别分析法在粉煤灰分类中的应用。通过对原始数据的分析,建立起反映粉煤灰质量等级的综合指标函数模型,从而提供了一种新的简单、快速、准确评定粉煤灰质量等级的方法。     

烧结法提取粉煤灰中氧化铝的新进展

在简述了粉煤灰的理化性能及矿物组成后,根据破坏粉煤灰中SiO2-Al2O3键及活化Al2O3的不同方式对提取粉煤灰中氧化铝的技术进行了分类,然后总结国内近十年来在烧结法提取粉煤灰中氧化铝方面取得研究新进展,并简要地评述了不同烧结法提取氧化铝工艺的优缺点,并展望了今后烧结法提取粉煤灰中氧化铝的研究方向。     

电厂粉煤灰渣排放与综合利用技术通则(报批稿)

电厂排放的粉煤灰、渣,既是固体废物,又是一种可开发利用的资源。为促进粉煤灰渣的综合利用,减少贮灰场占地,保护环境,提高社会、经济效益、特制定本通则。 1、主题内容与适用范围本标准规定了电厂粉煤灰渣综合利用量评价指标、粉煤灰渣的分类、排出与贮运技术,以及目前成熟利用的门类、相应的灰质及管理要求。     

火电厂粉煤灰微珠的分选利用

大型火力发电厂在生产运行过程中产生大量的粉煤灰,长期积存堆放,污染环境、占用土地.华能德州电厂通过研究实践,采用粉煤灰分选技术,生产出市场前景广阔的建材原料-微珠,提高了产品附加值,实现了废弃物的综合利用.     

粉煤灰高附加值利用研究进展

粉煤灰是火电厂燃煤过程中产生的固体残渣, 其成分复杂, 具有毒性, 若处理不当会对环境造成危害。因此, 粉煤灰的高附加值利用迫在眉睫。然而, 粉煤灰的品质是制约其高附加值利用的主要因素。目前, 中国粉煤灰品质参差不齐, 缺少完善的品质评价体系, 由此造成粉煤灰利用领域的局限性。针对上述问题, 首先分析了中国粉煤灰的资源化特性, 总结了粉煤灰的品质评价方法, 并重点阐述了适用于粉煤灰高附加值利用的品质评价方法;其次, 详细介绍了粉煤灰高附加值利用技术（高附加值提取技术、高附加值材料制备技术）;最后, 对粉煤灰高附加值利用的发展趋势做出了展望。     

Influence of fly ash fineness on strength, drying shrinkage and sulfate resistance of blended cement mortar

In this paper, the influence of fineness of fly ash on water demand and some of the properties of hardened mortar are examined. In addition to the original fly ash (OFA), five different fineness values of fly ash were obtained by sieving and by using an air separator. Two sieves, Nos. 200 and 325, were used to obtain two lots of graded fine fly ash. For the classification using air separator, the OFA was separated into fine, medium and coarse portions. The fly ash dosage of 40% by weight of binder was used throughout the experiment. From the tests, it was found that the compressive strength of mortar depended on the fineness of fly ash. The strength of mortar containing fine fly ash was better than that of OFA mortar at all ages with the very fine fly ash giving the highest strength. The use of all fly ashes resulted in significant improvement in drying shrinkage with the coarse fly ash showing the least improvement owing primarily to the high water to binder ratio (W/B) of the mix. Significant improvement of resistance to sulfate expansion was obtained for all fineness values except for the coarse fly ash where greater expansion was observed. The resistance to sulfuric acid attack was also improved with the incorporation of all fly ashes. In this case the coarse fly ash gave the best performance with the lowest rate of the weight loss owing probably to the better bonding of the coarse fly ash particles to the cement matrix and less hydration products. It is suggested that the fine fly ash is more reactive and its use resulted in a denser cement matrix and better mechanical properties of mortar.     

二次风量对LNJ-36A型气流分级机分级性能的影响

气流分级机二次风量是影响分级机性能的重要因素。通过实验探究二次风量变化对同种物料、不同粒度段及同种粒度段、不同物料分级效果的影响,并提出一种可以直接从粗、细粉粒度分布中得到的分级评价指标--相对分级精度δ,以此来评价分级效果好坏。实验结果表明,不同粒度段的粉煤灰和水泥熟料在相同二次风量的情况下,粒径较小的粉煤灰,其相对分级精度大于粒径较大的粉煤灰;粒径较小的水泥熟料,其相对分级精度大于粒径较大的水泥熟料;同种粒度段的粉煤灰和水泥熟料,在相同二次风量的情况下,相对密度较小的粉煤灰,其相对分级精度大于密度较大的水泥熟料;利用LNJ-36A气流分级机分级粉煤灰和水泥熟料,二次风流量保持在150m³/h、与主气流流量比例保持在0.168时,分级效果最好。     

Some aspects of characterisation,utilisation and environmental effects of fly ash

A review on fly ash, an important but problematic waste material is presented. The article deals with several aspects of the characterisation, extraction of metal values leaching and associated environmental pollution problems due to fly ash. Characterisation includes classification, physicochemical and mineralogical analysis, presence of organic carbon and the significance of cenospheres. Utilisation aspects are confined to extraction of metal values and discuss the elemental distribution in fly ash while also covering several aspects of leaching including the leaching of specific metals. Effect of fly ash on surroundings, including ground water pollution and associated problems during disposal, are considered while dealing with the environmental aspects. Some remedial measures are also suggested. © 2001 Society of Chemical Industry     

粉煤灰建材资源化的研究进展

粉煤灰是火力发电厂的副产品,利用粉煤灰生产建材是粉煤灰资源化的有效途径;结合粉煤灰的性质,介绍了粉煤灰建材资源化的研究进展,尤其是在水泥、混凝土、烧结砖和微晶玻璃等方面的最新研究成果;指出粉煤灰建材资源化还存在一些不足,需要进一步研究来提高粉煤灰利用量.     

Hydration of fly ash cement

It is necessary to establish the material design system for the utilization of large amounts of fly ash as blended cement instead of disposing of it as a waste. Cement blended with fly ash is also required as a countermeasure to reduce the amount of CO₂ generation. In this study, the influences of the glass content and the basicity of glass phase on the hydration of fly ash cement were clarified and hydration over a long curing time was characterized. Two kinds of fly ash with different glass content, one with 38.2% and another with 76.6%, were used. The hydration ratio of fly ash was increased by increasing the glass content in fly ash in the specimens cured for 270 days. When the glass content of fly ash is low, the basicity of glass phase tends to decrease. Reactivity of fly ash is controlled by the basicity of the glass phase in fly ash during a period from 28 to 270 days. However, at an age of 360 days, the reaction ratios of fly ash show almost identical values with different glass contents. Fly ash also affected the hydration of cement clinker minerals in fly ash cement. While the hydration of alite was accelerated, that of belite was retarded at a late stage.