综合利用煤矸石制砖的合理性分析

煤矸石大量排放积存,危害严重,根据性治理利用日趋紧迫。通过对多种不同煤矸石利用途径的利弊分析和优化选择,分析了综合利用煤矸石制烧结砖的合理性,并对煤矸石制砖项目总体方案进行比较、优化。     

综合利用煤矸石制砖的合理性分析

煤矸石大量排放积存,危害严重,根本性治理利用日趋紧迫。通过对多种不同煤矸石利用途径的利弊分析和优化选择,分析了综合利用煤矸石制烧结砖的合理性,并对煤矸石制砖项目总体方案进行比较、优化。     

山西煤矸石再利用

把煤矸石粉碎制成砖坯，再用传输带把砖坯送入砖炉，不用燃料，可自燃的煤矸石砖坯引燃后迅速生成建筑用砖，自燃过程的热能又替代了煤矿要用的燃煤锅炉。一条高科技的生产线就这样实现了变废为宝。     

浅谈煤矸石综合利用与生态环境

综合利用煤矸石,改善生态环境,实现可持续发展,当前最有效的措施是采用高新技术发展煤矸石烧结砖。利用煤矸石烧结砖可以治理现有的矸石堆积,腾出土地;减少制砖用黏土,保护良田;避免矸石污染及自然,保护环境。     

浅淡煤矸石综合利用与生态环境

综合利用煤矸石 ,改善生态环境 ,实现可持续发展 ,当前最有效的措施是采用高新技术发展煤矸石烧结砖。利用煤矸石烧结砖可以治理现有的矸石堆积 ,腾出土地 ;减少制砖用黏土 ,保护良田 ;避免矸石污染及自燃 ,保护环境。     

城市污水处理厂污泥制砖的试验研究

对城市污水处理厂污泥的主要化学组成进行分析,结果表明污泥中的主要化学组成与粘土相似,为城市污水厂污泥制转提供了有力的依据。采用污泥和粘土作为烧制砖体的原料,通过正交设计法设计试验方案,试验结果表明:烧结温度和污泥粘土配比是影响烧结砖体强度的主要因素;利用污水厂污泥烧制砖体的实验室最佳工艺条件为:烧结温度1020℃,烧结时间2h,污泥粘土配比1∶20。     

煤矸石砖窑余热利用研究

在煤矸石制砖过程中,砖坯在隧道窑冷却带携有大量高温能量,提出在隧道窑冷却带安装余热锅炉要考虑的问题,锅炉辅助设备的选择参数,如何解决原生产工艺的不足,从而增加了矸石砖的产量。同时介绍了项目产出高温高压蒸汽后的利用情况。     

烧结类墙材企业节能途径

目前烧结类墙材企业的特点是产业集中度低、规模小、生产方式简单、工艺技术落后和主要耗能设备窑炉热效率低,而且普遍存在着能源管理基础薄弱、能耗水平良莠不齐和余热利用水平低等问题,文中通过对烧结类墙材企业存在问题的分析,有针对性地提出了节能的方法和途径。     

山西省煤矸石环境影响及综合利用对策

本文论述了山西省煤矸石产生量，堆存量，煤矸石对环境的影响，并对山西省煤矸石目前的综合利用现状及利用中存在的问题进行了分析。     

煤矸石烧结空心砖原料制备和码烧工艺的特点

我国煤炭年产量约十亿吨,居世界第一位.煤炭生产和加工中产生的固体废弃物--煤矸石,目前累计堆存34亿吨,占地20万亩以上,而且每年还要新增占地6∞0多亩.煤矸石长期堆存和自燃,不仅侵占大量珍贵土地,而且污染大气和地下水质,构成了对环境的威胁. 我国政府对此高度重视,提出了"因地制宜,积极利用”的方针,并采取一系列政策,如资金补助、贴息贷款、减免税赋等扶持性措施鼓励煤矸石综合利用.国家经贸委、国家科技部颁布"煤矸石综合利用技术政策要点”指出"大力发展煤矸石空心砖等新型建筑材料”.     

连续烧结炉的PLC控制程序设计

介绍了连续烧结炉零件输送的PLC控制思想,并针对几个程序段详细地分析了控制方法。通过程序调试、修改,最终实现了对连续烧结炉零件输送的控制。该控制系统具有灵活性,一些相关参数可以随意修改,是一种很好的控制方法。     

烧结环冷机余热发电机组稳定运行的探讨

文中根据烧结环冷机余热发电生产过程中存在的问题,采取可行的措施,进行现场实际改进,取得明显效果,对同行业烧结环冷机余热发电具有指导意义.     

Full-scale simulation of flow field in ammonia-based wet flue gas desulfurization double tower

With the increasingly strict environmental requirements, sintering flue gas desulfurization in double tower had been applied to improve desulfurization efficiency and reduce the “ammonia escape” and “aerosol” phenomena. In this work, the operating conditions of a sintering plant were simulated by ANSYS CFX and the flow fields without and with fluid spray of a full-scale ammonia-based wet flue gas desulfurization (WFGD) double tower were investigated. According to the results, the evaporating tower had a profound cooling effect on flue gas with spray. The gas flow distribution was non-uniform in evaporating tower, which needed further optimizations. The flow with spray was more uniform in both towers. The pressure drop mainly took place in absorption areas of desulfurization tower. The velocity of inlet region with spray was lower than that without spray in desulfurization tower. The temperature decreased along with the forward direction of gas flow due to the heat transfer with spray in desulfurization tower. The study provided useful data for further optimization in order to achieve high desulfurization efficiency.     

Anode supported micro-tubular SOFC fabricated with mixed particle size electrolyte via phase-inversion technique

Cerium-gadolinium oxide is a promising material for electrolytes of intermediate temperature solid oxide fuel cells (IT-SOFCs) due to its high electrical conductivity at relatively lower temperatures of 400–700 °C. However, a high sintering temperature of up to 1550 °C is typically required to produce dense CGO electrolyte, eventually leading to an interfacial interdiffusion between the electrolyte and electrode components as well as generate a highly resistive interface which reduces ionic conductivity. Lowering the sintering temperature of the electrolyte will greatly benefit the fabrication of SOFCs. This study examines the effectiveness of introducing nano size CGO particles as an approach to get dense CGO electrolyte at lower sintering temperature. A series of dope suspensions with 0–50% nano size loading were prepared to observe rheology and measure viscosity. Then, 30% loading was selected and casting into flat sheet via phase-inversion technique. The flat sheet was characterized by morphology, surface roughness and mechanical strength tests. The suspension was extruded into dual-layer hollow fiber (DLHF) as well. The electrolyte/anode dual-layer hollow fibers (DLHFs) half-cell of micro-tubular solid oxide fuel cells (MT-SOFCs) were prepared via phase inversion based co-extrusion/co-sintering technique. The developed half-cell was characterized by morphological and gas tightness tests which further compared them with fully micron ones. The results show that the incorporation of 30% nanoparticle yielded to dense and tight CGO layers sintered at temperature 1450 °C, which about 50 °C lower than those reported previously for 100% micron particles. The I–V measurements demonstrated the maximum power density of 0.66 Wcm^?2 at temperatures 500 °C using 100% H₂ as fuel. Therefore, this approach is able to reduce the energy cost for the microstructural control of the prepared fiber and thus is recommended for the fabrication of low-cost dual-layer hollow fiber micro tubular SOFCs.     

Enhancing sinterability and electrochemical properties of Ba(Zr0.1Ce0.7Y0.2)O3-δ proton conducting electrolyte for solid oxide fuel cells by addition of NiO

The influence of NiO on the sintering behavior and electrical properties of proton conducting Ba(Zr_0.1Ce_0.7Y_0.2)O_3-δ (BZCY7) as an electrolyte supporter for solid oxide fuel cells is systematically investigated. SEM images and shrinkage curve demonstrate that the sinterability of the electrolyte pellets is dramatically improved by doping NiO as a sintering aid. The sintering aid amount and sintering temperature are optimized by analyzing the linear shrinkage, grain size and morphology for a series of sintered BZCY7 electrolyte pellets. Almost full dense electrolyte pellets are successfully formed by using 0.5–1.0 wt% NiO loading after sintering at 1400 °C for 6 h. The linear shrinkage of 0.5 wt% NiO modified BZCY7 sample is about 14.25% higher than that without NiO addition (4.81%). Energy dispersive X-ray spectroscopy analysis indicate that partial NiO might dissolve into the perovskite lattice structure and the other NiO react with BZCY7 to form BaY₂NiO₅ secondary phase as a sintering aid. Excessive NiO is especially detrimental to the electrical properties of BZCY7 and thus lower the open circuit voltage. The electrochemical performance for a series of single cells with different concentration NiO modified BZCY7 electrolyte are measured and analyzed. The optimized composition of 0.5 wt% NiO modified BZCY7 as an electrolyte support for solid oxide fuel cell demonstrates a high electrochemical performance.     

The effect of charcoal combustion on iron-ore sintering performance and emission of persistent organic pollutants

A study was carried out into the use of hardwood charcoal as a supplementary fuel in the iron-ore sintering process. The primary fuel was coke breeze with 0%, 20%, 50% and 100% replacement of the energy input with charcoal to produce raw blends with the same heat output as 4.0 wt.% coke breeze. Experimental results indicate that fuel blends where 20% of the heat input was provided by charcoal may improve both the sinter yield and sintering productivity by up to 8%, under normal sintering conditions. In addition, the 20% replacement of coke energy with charcoal would mean that part of the carbon dioxide emitted from the process would be from a renewable source and could be used to offset carbon dioxide emissions from non-renewable fossil fuels. At higher rates of coke breeze energy substitution with charcoal, the lower sintering performance observed was mainly attributed to the lower fixed carbon content and higher volatile matter content of the fuel mix.At the optimum rate of 20% substitution of coke breeze energy input with charcoal, the emission of dioxins were similar to those observed with coke breeze alone as the fuel. However, sintering with 20% energy input from charcoal resulted in a slight increase in middle molecular weight and lower molecular weight PAHs, contributing to a minor increase in B[a]P-eq from 0.15 μg/m³ to 0.17 μg/m³. Overall the results from the laboratory scale tests suggest that it is feasible to substitute 20% of the coke breeze energy input with an equivalent amount of energy from charcoal in the iron-ore sintering process.     

Effect of low thermal conductivity wick on the performance of compact loop heat pipe

The existing work deals with the evaluation of compact loop heat pipe by means of a low thermal conductivity sintered chrysotile wick to avoid large heat leaks as of the evaporator to the compensation chamber. Accordingly, a wick with low thermal conductivity (0.068–0.098 W/mK) chrysotile powder of a mean particle diameter of 3.4 μm is fabricated through sintering. Nine chrysotile wicks are sintered with different compositions of binders (bentonite and dextrin) and pore-forming agent NaCl at sintering temperatures of 500°C, 600°C, and 700°C with a sintering time of 30 min. The wick properties, for instance, porosity, permeability, wettability, and capillary rise are studied owing to sintering temperature. Consequently, it is observed that a pure chrysotile powdered wick at a sintering temperature of 600°C exhibits a high porosity of 61.8% with permeability 1.04 × 10⁻¹³ m² and a capillary rise of 4.5 cm in 30 s and is considered optimal. This optimal wick is used for performance evaluation in compact loop heat pipe and a decrease of 36.1% in thermal resistance is found when compared with copper mesh wick in a loop heat pipe. The lowermost thermal resistance originates to be 0.147 K/W at 120 W with wall temperature 57.7°C. This indicates that loop heat pipe with sintered chrysotile wick can operate at lower heat loads efficiently when compared with copper mesh wick and as heat load increases a chance of dry out condition occurs. The highest evaporative heat transfer coefficient obtained is 65.7 kW/m² K at a minimum heat load.     

Effect of Co2O3 as sintering aid on perovskite BaCe0.8Y0.2O3-δ proton conductive membrane for hydrogen separation

BaCe_0.8Y_0.2O_3-δ proton conductor powder was prepared by sol-gel method, and the effects of sintering temperature and sintering aids addition on the mechanical properties and hydrogen permeability of BaCe_0.8Y_0.2O_3-δ proton conductor were investigated. XRD tests showed that when the addition of sintering aid Co₂O₃ reached 5%, the BaCe_0.8Y_0.2O_3-δ proton conductor still showed a good perovskite phase. The sintering temperature of the sample with sintering aid is significantly lower than that of the blank sample. SEM shows that the addition of Co₂O₃, the proton conductor grains are closely arranged, the mechanical properties are increased, and the hydrogen permeability is significantly improved.     

Effect of sintering aids on sintering kinetic behavior of praseodymium doped ceria based electrolyte material for solid oxide cells

The present study investigates the effect of sintering additives (Li, Co, Fe, and Mg) on the sintering kinetic behavior of the praseodymium-doped-ceria (PDC) electrolyte of solid oxide electrolyzer cell. 3Li-PDC, 3Co-PDC, 3Fe-PDC, and 3 Mg-PDC pellets were obtained from the synthesis of PDC nano-powder by microwave-assisted co-precipitation method using isopropyl alcohol as a solvent and followed by sintering additive wetness impregnation method. Linear shrinkage and shrinkage rate data suggest a positive sintering effect for 3Li-PDC and 3Co-PDC pellets and a negative sintering effect for 3 Mg-PDC and 3Fe-PDC pellets than compared to PDC pellets alone. The addition of lithium as a sintering additive (3Li-PDC) had reduced the sintering temperature of PDC from 1100 °C to 850 °C. For PDC, 3Li-PDC, 3Co-PDC, 3Fe-PDC and 3 Mg-PDC pellets sintered at 1100 °C, 850 °C, 1000 °C, 1200 °C, 1100 °C for 2 h resulted in a relative density of 93.6 ± 0.25, 95.8 ± 0.45, 95.0 ± 0.20, 92.7 ± 0.10, and 94.5 ± 0.10%, respectively. The XRD patterns of the sintered PDC pellets suggested a secondary phase formation (PrO₂) in 3Co-PDC, 3Fe-PDC, and 3 Mg-PDC pellets indicating that the addition of these sintering aids results in poor solubility limit of Pr in CeO₂. On the other hand, XRD patterns of PDC and Li-PDC sintered pellets displayed no secondary peak indicating good solid-solution formation. The activation energy of the 3Li-PDC pellet is obtained from CHR and Dorn methods and was found to be 182 kJ/mol and 196 kJ/mol. From the CHR method, for the 3Li-PDC pellet, the initial sintering behavior is by the grain boundary diffusion mechanism (m = ~2).