Leaching Behavior of Fly Ashes from Power Plants

The Yanzhou mine district, located in southwestern Shandong Province, is about 1300 km2 with more than 8×109tons of proved coal reserves and there are 10 big power plants in this area. A large amount of coal ashes, which are regarded as waste materials, have been stockpiled in the area and have influenced the environment of the mine district. In this paper, analysis of fly ash samples from three power plants is carried out, the enrichment and concentration of trace elements, Pb, Zn, Cu and As, in coal ashes are analyzed, and petrological and mineralogical characteristics and chemical compositions of coal ashes are studied. The aim of this work is to provide basic scientific data for utilization of ashes and reduction of environmental pollutions.

Heavy metals distribution in fly ash from gangue power plant

To make assessment on its environmental security, fly ash samples were collected from the gangue power plant. Total content of heavy metals in sieved fly ash were analytically determined. We also carried out Tessier extractive experiments to check the chemical species of heavy metals. Experiment results show that the content of Cu, Zn, Pb and Cd ascend when particle size is smaller. Cu, Zn, Pb and Cd obviously enrich in particulate fly ash. The chemical species of heavy metal distribution ranking sequence generally is residual〉organic combinative〉Fe-Mn oxide combinative〉carbonate combinative〉ion-exchangeable. Lead＇s amiable-move species were high in proportion, amounted to 35%. Total content of Cadmium is at low level, but its ion-exchangeable species is relatively high in proportion. Nickel and zinc is mainly distributed in residue. Cu is mainly distributed in residue and organic combinative form. The content of manganese is relatively high in fly ash, and the carbonate combinative iron-manganese oxide combinative species are main chemical form. Cr is mainly distributed in residue, and its other chemical species are at low level. Compared with the soil background value of study area and Shandong Province, the content of Cu, Ni, Zn, Mn and Cr in fly ash of gangue power plant is lower. While contents of Pb and Cd were higher than background value, and amiable-move species is relatively high in proportion. They are more apt to cause heavy metal pollution.

Getting and X-ray Diffraction Analysis of the Microsphere Catalyst U, Nd on the Basis Fly Ash of Thermal Power Plants

To study the physical and chemical properties of aluminosilicate microsphere catalyst by impregnation and calcination us was first obtained aluminosilicate microsphere catalyst U, Nd for petrochemical processes. The method of X-ray structure has been studied for the microsphere catalyst U, Nd.

Effects of NaOH Concentrations on Properties of the Thermal Power Plant Ashes-Bricks by Alkaline Activation

The use of the thermal power plant ashes including fly ash(FA) and bottom ash(BA) for producing unfired building bricks(UBB) using sodium hydroxide(NaOH) solution as an alkaline activator was investigated. A low applied forming pressure of 0.5 MPa and various NaOH concentrations of 5, 8, 10, and 12 M were used for the preparation of brick samples with different solution-to-binder(S/B) ratios of 0.35 and 0.40. The bricks were subjected to various test programs with reflecting the effect of both NaOH concentrations and S/B ratios on the brick’s properties. The compressive strength, unit weight, ultrasonic pulse velocity, and thermal conductivity of bricks increased with increasing NaOH concentration, whereas the contrary trend was found with increasing S/B ratio. Also, the water absorption of bricks was observed to reduce with increasing NaOH concentration and decreasing S/B ratio. As the results, the combined utilization of both low forming pressure and coal power plant ashes can produce the UBBs with low unit weight, low heat conductivity, and acceptable strength and water absorption rate as stipulated by TCVN 6477-2016. Furthermore, the outcomes of chemical analysis and microstructure observation also demonstrate that a high concentration of the Na OH promoted the geopolymerization process. Notably, the use of NaOH solution of either 10 M or above is recommended for the production of UBBs, which are classified as grade M5.0 or higher.

火电厂粉煤灰与脱硫石膏资源化利用现状

火力发电厂主要产生的固态废弃物为粉煤灰和脱硫石膏,由于未能得到充分的运用,我家每年都会积累大量的此类废弃物。基于对粉煤灰和脱硫石膏的规范化利用,以及相关法律法规、政策文件和利用技术的详细研究和理解,深入探讨粉煤灰的现行利用状况。近年来,我国对粉煤灰的利用模式并未经历明显的变迁。主流的应用领域依然是水泥、混凝土及各类建材的深度加工产品。这些领域的应用,不仅充分利用粉煤灰的特性,而且也在一定程度上缓解环境压力。然而,尽管粉煤灰在这些领域的应用已经相当成熟,但在其他一些可能的应用方向上,如道路建设和土地回填等,开发和利用却相对较少。脱硫石膏的应用路径具有较高的多样性,其主要被应用于作为建筑材料中的石膏和水泥固化剂。此外,其也被用于生产复合凝胶材料、土壤改良、硫酸钙晶须制备,以及其他高附加值化学品的生产等领域。建议在已经有成熟应用的领域中,进一步拓宽粉煤灰和脱硫石膏在我国的利用范围。深化粉煤灰与脱硫石膏的高附加值科技探索,提升其综合运用的良性层次。

火电厂运行调整及锅炉燃烧调整对飞灰品质的影响分析

锅炉是火电厂运行中的重要设备,主要利用煤粉燃烧产生的热量进行汽轮发电。但是,锅炉燃烧期间会产生大量飞灰,如果飞灰中的含碳量超出了要求标准,则会影响飞灰品质,还容易对周围环境造成污染。火电厂运行调整和锅炉燃烧调整都会对飞灰品质产生不同程度的影响,要清楚各类要素的影响程度,并从提高飞灰品质和降低飞灰中含碳量的角度出发,做好火电厂运行调整、锅炉燃烧调整以及优化煤种质量和配置等工作,完善调整控制措施,切实提升锅炉燃烧中飞灰的质量。

火力发电厂灰库清灰作业风险控制措施

针对火力发电厂灰库清灰作业的危险性,从风险分析、作业前准备、安全技术措施、安全管理措施四个方面,介绍了灰库清灰作业风险控制措施,相关措施的实践与应用可有效防范灰库清灰作业的安全生产事故,提高作业安全水平。

火电厂锅炉运行调整对飞灰品质的影响

在火力发电厂的日常工作中,飞灰质量是衡量其燃烧效能和改善其运行环境的一个重要指标。锅炉在燃烧时,受多种因素的影响,如燃烧物、热风温度等,都会对飞灰品质产生很大的影响,进而影响到电厂的发电效率。基于此,以某火力发电厂的运行方式、锅炉设备的调整等方面为例,根据实际工作需求,对如何降低飞灰的含碳量、保证飞灰品质提出方法措施。

燃煤耦合污泥发电机组电除尘器腐蚀诊断

某火力发电厂2台1 000 MW燃煤耦合污泥发电机组,电除尘器的极板和极线被积灰覆盖,腐蚀严重,使用寿命缩短。通过检测极板和极线上的积灰与腐蚀产物,同时结合污泥掺烧、设备运行调查情况,对腐蚀机理及原因进行了分析。结果表明:机组掺烧污泥后,脱硝催化剂严重积灰、磨损,导致氨逃逸率持续偏高,氨逃逸生成的硫酸氢铵、硫酸铵等强酸性盐在极板和极线表面产生黏性沉积,该灰垢吸湿潮解,形成强酸性电化学腐蚀环境,造成金属严重腐蚀;入炉煤的碱金属、氯含量较高,颗粒态氯盐随黏性灰沉积在极板和极线上,促进了电化学腐蚀。

基于粒子群算法的火力发电厂粉煤灰高性能混凝土配合比优化

当前火力发电厂粉煤灰混凝土配合比计算常基于单一环境,文章提出基于粒子群算法的粉煤灰高性能混凝土配合比优化方案,明确材料基础掺量,增强多环境计算的可靠性,构建优化模型,采用抗渗测定优化配合比。实验结果表明,经过三个配合比优化阶段的测定,测试构件的抗压强度均可以达到30 MPa以上,说明在粒子群算法的辅助下,优化方法的针对性更高。

Development of Sensible Heat Storage Materials Using Sand, Clay and Coal Bottom Ash

In this paper, the mechanical and thermal properties of a sand-clay ceramic with additives coal bottom ash (CBA) waste from incinerator coal power plant are investigated to develop an alternative material for thermal energy storage (TES). Ceramic balls are developed at 1000°C and 1060°C using sintering or firing method. The obtained ceramics were compressed with a compression machine and thermally analyse using Decagon devise KD2 Pro thermal analyser. A muffle furnace was also used for thermal cycling at 610°C. It was found that the CBA increased the porosity, which resulted in the increase of the axial tensile strength reaching 3.5 MPa for sand-clay and ash ceramic. The ceramic balls with the required tensile strength for TES were selected. Their volumetric heat capacity, and thermal conductivity range respectively from 2.4075 MJ·m-3·°C-1 to 3.426 MJ·m-3·°C-1 and their thermal conductivity from 0.331 Wm-1·K-1, to 1.014 Wm-1·K-1 depending on sand origin, size and firing temperature. The selected formulas have good thermal stability because the most fragile specimens after 60 thermal cycles did not present any cracks. These properties allow envisioning the use of the ceramic balls developed as filler material for thermocline thermal energy storage (structured beds) in Concentrating Solar Power plants. And for other applications like solar cooker and solar dryer.

可调频声波吹灰器在火电厂的应用

可调频声波吹灰器在处理火电厂锅炉积灰、结焦方面具有较好的效果。文章对锅炉受热面积灰的原因进行分析,阐述了可调频声波吹灰器的系统构成以及工作原理,对声波吹灰器在实际工作中的应用进行了较为全面的描述,分析了可调频声波吹灰器在锅炉吹灰应用方面的优点,为面临相关问题的机组改造工作提供一定的借鉴。

热电厂脱硫灰的综合利用

分析了脱硫灰性质及其排放方式对粉煤灰综合利用的影响,认为脱硫灰的不安定性限制了其在建材领域的应用,而解决该问题的方法在实际生产中难以实现。目前,脱硫灰综合利用途径为制造硫铝酸盐水泥、粉煤灰砖、矿物聚合材料以及用于土壤改良。

粉煤灰土壤改良剂在现代种植环境中的应用研究(英文)

在研究分析中国现代种植环境中土壤微量元素循环的规律和缺乏现象的基础上,针对其不可持续性提出了选用低灰和低有害物质的粉煤灰作为土壤微量元素补充改良剂使用的理论观点,并通过选择用以大同煤为燃料的胜利油田发电厂排出的粉煤灰为研究对象,在龙口地区进行了大田种植玉米的试验研究。研究结果表明某些低灰的且有害元素含量少的煤所形成的粉煤灰,可以作为土壤微量元素补充的改良剂来大量使用并获得较好的土壤改良和农作物增产的效果。

电厂湿法脱硫系统石膏脱水困难的影响因素

针对火电厂湿法脱硫系统,结合实例,对可能造成石膏脱水困难的常见因素进行了分析。结果表明,石膏脱水系统运行情况的优劣直接影响石膏脱水效果,且原烟气SO2浓度和飞灰含量,脱硫反应条件,吸收塔系统、废水处理系统设备的运行,石灰石浆液质量等均影响石膏的脱水效果。

火电厂输灰管路浆体水击瞬变过程数值计算与分析

水力输灰在火电厂中获得越来越广泛的应用。在浆体水击瞬变过程基本方程的基础上,运用特征线方法建立了考虑含气量的伪均质浆体停泵水击瞬变过程数学模型。对某火电厂输灰复合管道计算了当水泵发生事故停泵时,水泵出口压力相对值,泵的无因次流量,泵的无因次转速,管道顶端最高点处的压力水头相对值的瞬变过程。通过对数值计算结果的分析,提出了在管道顶端最高点设置调压井和增大电机飞轮力矩的方法来降低管道中浆体水击的危害。

火电厂锅炉飞灰含碳量测量技术发展与现状

飞灰含碳量是反映火电厂锅炉燃烧效率的重要指标,提高锅炉运行效率的关键前提是精确和快速地测量出飞灰含碳量。全面介绍了当前常见的多种飞灰含碳测量方法的工作原理,分别了它们的优缺点,并给出了典型产品。还详细地介绍了近年来发展起来的飞灰含碳量数据融合测量方法和软测量方法,并分析了它们的技术特点。对飞灰含碳量测量方法的选择与研究有一定的参考指导价值。

电厂粉煤灰选沉珠对微孔隔热涂料性能的影响

为了降低微孔隔热涂料的体积密度,提升涂料的隔热性能,并实现电厂废弃物粉煤灰选沉珠的废物利用,采用粒径为0.105~0.38 mm的沉珠和粒径0.125 mm的玻璃微珠为主要原料,钠基膨润土、凹凸棒土和Si O2微粉为增塑剂,以硅溶胶为结合剂,在仅以玻璃微珠为主的隔热涂料基础上,以质量分数分别为20%、40%、60%和80%的沉珠替代玻璃微珠,研究了沉珠加入量对涂料常温力学性能、抗挠性能、导热性能和显微结构的影响。结果表明:沉珠的引入可明显降低涂料的体积密度并提高显气孔率,从而改善涂料的隔热性能,但体积密度降低的同时常温力学性能也有所下降;在0.105~0.38 mm粒径范围内,粒径的改变对抗挠性影响微乎其微。综合考虑,沉珠加入量应在60%(w)左右为宜。