碳化硅陶瓷膜管高温除尘实验研究

采用自制碳化硅陶瓷膜管对某电厂烟气进行了高温过滤性能和再生效果的实验研究。主要考察了三种陶瓷膜管的处理气量对过滤效率、阻力损失的影响以及反吹再生效果。结果表明,随着含尘烟气量的增加,过滤效率逐渐降低,同时压降损失逐渐增大;复合膜的过滤性能优于单一膜或支撑体,反吹再生效果最佳。     

高温除尘碳化硅膜的制备及其抗腐蚀特性

采用喷涂法在碳化硅(SiC)支撑体上覆膜,根据碳化硅材料的氧化特性,设计了有氧烧结和氩气烧结随温度转换的组合烧结制度,并通过优化保温时间降低碳化硅陶瓷膜烧结成本。研究结果表明,新的烧结制度能有效地控制有氧烧结阶段产生的二氧化硅(SiO_2)量,并促进其与烧结助剂氧化锆(ZrO_2)等在气氛烧结阶段的反应,反应生成的锆英石相和添加莫来石相共同形成SiC颗粒连接颈部。制备的碳化硅陶瓷膜平均孔径为3.03μm,气体通量为175 m~3?m~(-2)?h~(-1)?kPa~(-1)。且在100℃的0.25 mol?L~(-1)的H_2SO_4溶液和0.25 mol?L~(-1)的NaOH溶液中腐蚀6 h后,膜层表面形貌无明显变化,具有较强的抗腐蚀性能。     

低温烧结碳化硅陶瓷分离膜的制备及其油水分离性能（英文）

碳化硅陶瓷分离膜具有高亲水性、耐化学腐蚀、抗膜污染等优异性能,在大宗废水、强腐蚀废水、高温废水等的高效处理中受到广泛的关注。然而,碳化硅是典型的强共价键化合物,碳化硅陶瓷膜制备过程具有烧结温度高、制备能耗大等问题。本文采用优选的低熔点化合物作为烧结助剂,经1 000℃烧结制备了高强度、孔径均匀的碳化硅陶瓷分离膜。研究了烧结助剂含量对碳化硅陶瓷膜微观结构、孔径分布、相组成及油水分离性能等的影响。研究表明,低熔点烧结助剂连接碳化硅颗粒形成陶瓷的骨架结构,随着烧结助剂含量从10%（质量分数）增加到30%,碳化硅陶瓷膜的孔隙率从42%降低到35%,同时平均孔径从3.5μm降低到2.1μm,成孔模式由碳化硅颗粒堆积过渡到烧结助剂成孔。纯水实验表明,烧结助剂含量为30%时,随着跨膜压差从0.2 bar增加到0.5 bar碳化硅陶瓷膜的分离通量从120 L/（m²·h）增加到306 L/（m²·h）;油水分离实验表明,当跨膜压力差为0.2 bar时碳化硅陶瓷膜的截留率和分离通量分别为93.3%和123 L/（m²·h）。     

碳化硅陶瓷膜的制备及其应用进展

碳化硅陶瓷膜具有耐高温、抗热震、耐腐蚀、高通量、使用寿命长等优势,是环境污染治理领域中的关键材料。如何制备面向应用过程的高性能碳化硅陶瓷膜已经成为目前的研究热点。本综述介绍了碳化硅陶瓷膜的成膜方法,包括浸渍提拉法、喷涂法、化学气相沉积法及相转化法。此外,阐明了各方法的成型机理、影响因素及优缺点等,概述了碳化硅膜烧结技术的机理、特点及研究现状,包括重结晶技术、前体转化技术、原位反应烧结技术及新型烧结技术,其中重点描述了共烧技术的实际应用价值及挑战,利于明晰碳化硅陶瓷膜性能与制备工艺的关系。并阐明了碳化硅陶瓷膜在高温烟气净化、油水分离、气体分离领域中的应用现状及前景,最后对碳化硅陶瓷膜工业化应用潜力作出展望。     

碳化硅陶瓷膜管制备及活性焦再生气除尘试验研究

冶金行业烟气治理活性焦干法脱硫过程中产生的活性焦再生气中含有焦炭粉尘,对下游硫资源化产品的品质有较大影响,必须进行高温除尘.试验制备了碳化硅陶瓷膜管并测定了其物理特性,认为其高温下具备较高的机械强度和较好的气体渗透性能.将该膜管用于活性焦再生气高温除尘试验结果显示,碳化硅陶瓷膜过滤器运行稳定,除尘效果良好,且膜管表面可...     

碳化硅质高温陶瓷膜的低温烧成

本文以碳化硅骨料、章村土系结合剂和核桃壳粉为原料,通过等静压成型工艺和 低温烧结制备了碳化硅质高温陶瓷膜材料。研究了成型压力对坯体强度以及成型压力和烧成温 度对膜材料强度、孔径、气孔率和透气阻力的影响。结果发现,当成型压力为 70 MPa、烧成温 度为 1250~1270?C 时,制品综合性能较优。     

碳化硅及其复合材料的烧结

本文分析了ＳｉＣ及其复合材料设计与烧结关系,新烧结新工艺的特点和发展趋势,探讨ＳｉＣ及其复合材料烧结驱动力脑海在化烧结机理,讨论了助剂向我功能多组分发展趋势。     

除尘脱硝一体化高温陶瓷过滤材料研究进展

本文主要介绍了除尘脱硝一体化高温陶瓷膜材料的工作原理、不同膜材料催化剂的负载工艺及一体化膜材料市场应用情况,分析了目前存在的问题,并对今后的发展趋势进行了展望。     

高温除尘用微粉SiC多孔陶瓷的制备和性能研究

本文以平均粒径为2.4 μm微粉SiC颗粒作为多孔陶瓷的主要原料,活性炭和石墨为造孔剂,再添加陶瓷粘结剂和羧甲基纤维素钠(CMC)溶液,采用逐层包覆工艺混料成型.将成型后的胚体在1300℃下烧结出不同陶瓷粘结剂含量(5～ 15wt％)(下同)以及不同成型压力(5～20 MPa)下的多孔陶瓷并研究了其气孔率、收缩率、过滤压降及抗压强度随陶瓷粘结剂含量以及不同成型压力下的变化.研究表明多孔陶瓷的气孔率随着成型压力由12.2MPa增加到48.8 MPa和粘结剂含量5％增加到15％气孔率逐渐降低,其抗压强度分别随着胚体成型压力的增大和粘结剂含量的增加而增加,烧结后胚体收缩率随粘结剂含量有先降低后增加的趋势.在粘结剂含量为10％时,成型压力19.52 MPa下多孔陶瓷的抗压强度和显气孔率都取得了较高的值,分别为31.75 MPa和29.87％,室温下空气流量为0.016 m3·h-1时,过滤压降为21.23 hPa.     

反应烧结制备碳化硅陶瓷及其性能研究

以全细粉碳化硅(d50=3.6μm、w(SiC)≥98％)为主要原料,加入炭黑、石墨、减水剂和分散介质等混合均匀后注浆成型,80℃烘干并于1720℃反应烧结制备全细粉碳化硅陶瓷材料.考察了搅拌时间1～5 h、炭黑加入质量分数5.62％～6.93％对素坯性能的影响,并对素坯及烧后试样微观结构进行表征.结果表明:添加石墨所...     

Preparation and properties of SiC/SiC-SiYC with excellent water-oxygen corrosion resistance

In this study, the SiC/SiC-SiYC composites were fabricated via chemical vapor infiltration (CVI) combined with the reactive melt infiltration (RMI) process. The excellent infiltration of Si-Y alloy assisted in fabricating composites with a density of 2.94 g/cm³ and a porosity of only 2.0%. After 20 h of corrosion at 1300 °C in the water-oxygen environment, the generated oxide layer, consisting of a glass layer and a diffusion layer, effectively protected the composites, and the flexural strength retention is 114.2%. This study highlights the significant potential of Si-Y alloy as a modification phase that is resistant to water and oxygen. It also presents a novel approach for developing high-density ceramic matrix composites that are resistant to water-oxygen corrosion.     

Preparation of high-purity SiC ceramics with good plasma corrosion resistance by hot-pressing sintering

High-purity SiC ceramic devices are applied in semiconductor industry owing to their outstanding properties. Nevertheless, it is difficult to densify SiC ceramics without any sintering additive even by HP sintering. In this work, high-purity and dense SiC ceramics were fabricated by HP sintering with very low amounts of sintering aids. Residual B content was only 556 ppm and relative density was more than 99.5%. Furthermore, thermal conductivity of as-prepared SiC ceramics was improved from 155 W m^?1 K^?1 to 167 W m^?1 K^?1 by increasing holding time and their plasma corrosion resistance was promoted in the meantime. The as-prepared high-purity SiC ceramics have broad application prospects in the field of semiconductor industry.     

复混肥除尘技术分析与比较

对复混肥生产中各类粉尘的特性进行分析,介绍目前主要的除尘技术,并针对复混肥生产中各类粉尘的特性提出了相应的除尘建议,为复混肥装置设计和技术改造提供参考。     

高耐蚀常温磷化液的研制

以普通的常温磷化液为基础，利用水溶性高分子覆膜，研制出一种高耐蚀常温磷化液。介绍了该常温磷化液的配方、操作条件、磷化液中各成分的作用及操作条件的控制。以丙烯酸为单体合成该水溶性高分子物质。检测了该磷化膜的耐蚀性能，结果显示，试片经该磷化液浸渍10s后，硫酸铜点滴试验时间大于60s，而浸渍15min后，硫酸铜点滴试验时间大于80s，氯化钠浸渍试验时间可达8h，表明其耐蚀性大大强于普通的常温磷化膜，可满足批量生产的需要。     

Low temperature seamless joining of SiC using a Ytterbium film

Monolithic SiC, for the first time, was seamless joined at a low temperature of 1200 °C using electric field-assisted sintering technology. A 300 nm Yb coating on SiC was used as the joining filler to form Yb₃Si₂C₂ via an in-situ reaction with the SiC. A liquid phase was formed by an eutectic reaction between Yb₃Si₂C₂ and SiC. Almost completely seamless joints were formed by the precipitated SiC grains, which were fully consolidated with the SiC matrix with the help of in-situ formed liquid phase, followed by its elimination under the uniaxial pressure. The bending strength of the seamless joint joined at 1500 °C for 15 min was as high as 257.2 ± 31.1 MPa, which was comparable to the strength of the SiC matrix. As a result, the failure occurred in the matrix indicated a sound joint was obtained. The proposed low temperature seamless joining could potentially be used for joining of SiC-based composite.     

Highly porous fibrous mullite ceramic membrane with interconnected pores for high performance dust removal

Porous fibrous mullite ceramic membranes with different content of fibers were successfully fabricated by molding method for dust removal. The properties of the samples, such as microstructure, porosity, bulk density and mechanical behavior were analyzed. Owing to the highly porous three-dimensional structure of ceramic membranes, all the samples exhibited low density (lower than 0.64?g/cm³), high porosity (higher than 73%), low linear shrinkage (lower than 1.0%) and low thermal conductivity (lower than 0.165?W/mK). Significantly, the as-prepared porous ceramic membrane possessed of enhanced dust removal efficiency with almost 100% for 3–10?µm, 97% for 1.0?µm, 87% for 0.5?µm and 82% for 0.3?µm dust particles in diameter from dust-laden air passed through the test module. Moreover, the pressure drop was lower than 80?Pa when the airflow linear velocity reached 1.25?m?min^?1. The results indicated that the ceramic membranes prepared in this work were promising high efficiency dedusting materials for the application in gas filtration field.     

超重力旋转床微米级粉尘脱除的试验研究

用超细滑石粉模拟工业微米级粉尘,通过试验研究了超重力平面丝网旋转床的除尘特性。考察了旋转床在实验室不同的气体流量、液体流量、转速和平面丝网层数条件下的除尘效果,试验结果表明,气体流量600m~3/h、液体流量大于0.6 m~3/h、转速1400 r/min、轴向放置3层平面丝网时,除尘总效率大于97%,设备压力降不超过490 Pa。该旋转床具有高效除尘和低阻性能,若在硫酸净化系统中使用,预期可获得节能与高效净化效果。     

超重力旋转床脱除微米级粉尘的实验研究

用超细滑石粉模拟工业微米级粉尘,通过实验研究了超重力旋转床的除尘特性.考察了旋转床在不同的气量q<,G>、液量q<,L>、转速n和轴向放置平面丝网层数n<,m>下的除尘效果,确定了实验室规模下适宜的除尘工艺条件:q<,G>=600 m<'3>/h,q<,L>>0.6 m<'3>/h,N=1 400 r/min,n<,m...     

湿化学法制备多通道ZrO_2超滤膜

采用孔径为200 nm的多通道ZrO2膜为底膜,利用湿化学法制备小孔径ZrO2超滤膜。结合N2吸附-脱附法和X线衍射分析,考察烧结温度对膜结构的影响,确定合适的烧结温度。通过扫描电镜(SEM)表征膜形貌,采用错流过滤考察膜的渗透和分离性能。结果表明:烧结温度为600℃时可以制备完整无缺陷的ZrO2超滤膜,所制备的超滤膜具有高纯水通量,截留相对分子质量(MWCO)为20 000,对相对分子质量为43 000卵清蛋白的截留率达到95%。