焦炉硅火泥用天然硅质原料的性能分析及选用

硅质耐火泥在焦炉用耐火材料中与硅砖是同等重要的材料,对焦炉的寿命影响很大。为了使硅质耐火泥能够满足未来超大容积焦炉的使用需要,从配置硅火泥的原料入手,研究了各种因素对硅火泥性能的影响。     

粒度级配对混煤水煤浆浓度与黏度的影响

水煤浆浓度与黏度是衡量水煤浆性能的两个重要指标.粒度级配是影响水煤浆性能的关键因素,合适的粒度级配可提高水煤浆性能.以某水煤浆厂所用的精煤和分散剂为实验基础,研究了在该水煤浆厂常用的混配煤和两种常用的分散荆条件下,粒度级配和水煤浆浓度、黏度的关系,获得了使用不同分散剂时水煤浆性能最佳时所对应的粒度级配.     

高级硅质火泥的研制与应用

硅砖在玻璃熔窑中主要用于上部结构,如碹顶和胸墙等处,砌筑硅砖所用的泥料品位至少应与砖材等同,甚至高于砖的等级。本文介绍了高级硅质火泥的研制和火泥的性能以及其应用效果。     

硅砖大(石旋)的(石旋)滴和“鼠洞”的形成问题

本文讨论了玻璃熔窑硅砖大(石旋)产生(石旋)滴和“鼠洞”的原因以及预防措施,简述了碱尘和碱蒸汽的侵蚀、硅质火泥中氧化铝含量的影响和在筑炉施工中的注意事项。     

不定形耐火材料粒度组成控制

本文根据国外文献资料，综述粒度组成对不定形耐火材料作业性能和物理性能的影响。简介颗粒级配理论（颗粒级配方程），及不定形耐火材料粒度组成控制（粒度分布系数ｑ值与作业性能和物理性能的关系）。     

加重材料粒度对高密度水泥浆性能的影响

根据粒度级配和紧密堆积原理,在室内建立了紧密堆积颗粒级配模型,根据级配模型,利用室内优选出的加重剂赤铁矿和重晶石的不同粒度颗粒进行了级配水泥浆加重实验。以嘉华G级高抗硫油井水泥、赤铁矿、重晶石等为基本原料,通过级配不同颗粒大小的赤铁矿配制密度为2.4g/cm^3水泥浆和同种颗粒大小重晶石和赤铁矿配制密度为2.2g/cm^3-2.3g/cm^3的水泥浆。并对水泥浆密度、稳定性、流动度、流变性、失水、稠化时间、抗压强度等进行测定,找出加重材料粒度级配与高密度水泥浆性能的基本关系。     

直径间隙法制水煤浆级配技术研究

采用双珠级配与三珠级配模型,探讨了球料比、研磨时间、温度、入料尺寸和研磨速度对灵武煤制水煤浆成浆性的影响,分别采用干法配浆与湿法配浆的方法进行实验,利用DV-1+PRO数字式黏度计和Rise-2008型激光粒度分析仪对配置浆料的黏度和粒度进行测试.结果表明,当入料尺寸<1mm,球料比为6∶1,研磨速度为72r/min时,水煤浆的浓度可以达到68%.10#自制添加剂的使用可以获得性能稳定的水煤浆浆体.     

高级硅质火泥在玻璃熔窑砌筑中的应用

高级硅质火泥粘结力强,用蘸浆法砌筑,可保证砌体质量,具有较高的耐火度和荷重软化点,可用于硅质砖材的砌筑,保证碹结构的整体性。     

粉末药型罩金属粒度级配及热处理对聚能射流性能的影响

利用筛分法,将127型石油射孔弹药型罩中的铜粉进行颗粒分级,并与其他金属粉进行粒度级配,通过粒度分布分析及射孔弹侵彻钢靶试验,研究了粉末药型罩中金属颗粒的粒度级配及分布对聚能射流性能的影响,同时对药型罩进行了热处理研究.结果表明,射孔弹药型罩中铜粉的粒度对聚能射流性能有重要影响,合理的金属粒度级配及分布能提高射孔弹侵彻钢靶的能力.粉末药型罩经热处理后,可提高药型罩的致密性和强度,能有效地改善聚能射流性能.优化后的药型罩使127型石油射孔弹侵彻钢靶深度提高11.6%.     

水煤浆棒磨机钢棒装填量工业实验

棒磨机的钢棒充填量及钢棒级配直接影响水煤浆的粒度分布,而粒度分布又是影响煤浆成浆性能的主要因素。通过工业试验摸索棒磨机的钢棒充填量及级配,从而生产出粒度分布合格的水煤浆。     

Hydraulic lime mortars with siloxane for waterproofing historic masonry

Mortars with different content of hydraulic lime and aggregates of a siliceous and carbonaceous nature differing in grain size, were designed for waterproofing historic masonry. The repair mortars design was taken into consideration the physico-chemical properties of the original ones. The water repellency of the designed mortars was enhanced through impregnation with an oligomeric organo-siloxane provided optimum water vapour permeability; this is due to the siloxane coating the capillaries without blocking the pores, as indicated from the slightly modified pore size distribution. The grain size of aggregates and the binder content influence the performance of mortars. Mortars with coarse aggregates develop high mechanical strength; nevertheless, micropores interconnected with macropores are responsible for the low salt-decay resistance. Increase of the binding content enhances the mechanical resistance but decreases the resistance to sulphate solutions, as a consequence of the small capillaries not allowing for salt crystallization. The mortar with the best performance consists of medium aggregates and a binder to aggregate ratio equal to 0.33; pores around 0.2 μm of radius enable salts to crystallize without provoking damage from crystallization pressure. The selected mortar, after fourteen months of application to the masonry, shows neither microcracks nor efflorescence formation.     

基于不同激发机理再生微粉活性激发制备砂浆应用性能对比研究

以再生微粉砂浆的应用性能为指标,对比研究了五种不同激发剂激发下,两种再生微粉FB和FC砂浆在不同的激发剂用量的情况下,砂浆的孔隙率、平均孔径、孔径分布、抗冻融性能等,研究结果发现LQ1和LQ2激发下,再生微粉砂浆的强度高,干缩小,孔隙率低,孔径分布均匀,吸水率低,抗冻融性好.     

Effect of α-Si3N4 Particle Size on the Microstructural Evolution of Si3N4 Ceramics

The effects of initial particle size on the microstructure of silicon nitride ceramics produced by pressureless sintering have been investigated. The microstructures of the silicon nitride ceramics varied considerably with the size of the initial powder. With decreasing powder size, abnormal grain growth was enhanced, which resulted in significant bimodal distribution of grain size. The observed results are discussed in relation to the two-dimensional nucleation and growth theory for faceted crystals.     

钙镁复合氯盐对β-SiC整形的影响

碳化硅材料用途十分广泛,为了制备高性能碳化硅材料,粉体的质量是关键,其中机械整形法是最常用的一种方法,但整形效果较差.采用化学整形法研究了熔盐体系钙镁复盐对碳化硅粉体晶体形貌、粒度分布、D50、D90等特性的影响.结果表明:MgCl2-CaCl2熔盐体系对β-SiC粉体晶体有长大作用,随保温温度的升高,晶粒形貌由层状结构向柱状结构过渡,D50表现为增大,D90也表现为增大;随保温时间的延长,晶粒形貌由细小颗粒向大颗粒过渡,D50和D90均逐渐变大.     

碳纳米管-水泥基复合材料的力学性能和微观结构

研究了掺碳纳米管水泥砂浆的力学性能和微观结构,并与掺碳纤维水泥砂浆的性能进行了对比。低含量的碳纳米管-水泥复合材料具有良好的抗压强度和抗折强度。用扫描电镜对碳纳米管-水泥复合材料以及碳纤维-改性水泥复合材料的微观结构进行了分析。结果表明：复合材料中碳纳米管表面被水泥水化产物包裹,同时碳纳米管水泥砂浆的结构密实。碳纤维表面光滑,在碳纤维与水泥石之间存在明显裂缝。孔隙率测试结果表明碳纳米管的掺入改善了材料的孔结构。     

大粒径纳米二氧化硅的制备技术

介绍了一种制备大粒径、高浓度硅溶胶的工艺方法,研究了硅溶胶生产中影响纳米二氧化硅粒径的增长因素。结果表明,纳米二氧化硅粒径的平均大小、粒度分布受pH值、温度、杂质离子浓度等诸多因素的影响,控制条件处于最佳状态有利于二氧化硅粒径均匀提高。     

矿渣颗粒对砂浆性能的影响

研究了矿渣颗粒以不同比例替代河砂时对砂浆流动度和强度的影响规律。结果表明:(1)采用补水法制备含矿渣颗粒的砂浆,可以克服因矿渣颗粒吸水造成的流动度降低;(2)随着矿渣颗粒掺入量的增加,砂浆3d,7d的抗折、抗压强度下降,而28d抗折强度随矿渣颗粒替代河砂比例的增加变化不大,28d砂浆抗压强度随着矿渣颗粒替代量的增加是先减小后增加;(3)矿渣颗粒在建筑砂浆中具有陶粒的某些性能,通过吸水返水作用可以提高建筑砂浆的强度增进率。     

Rheological properties of magnesite — Phosphate mortar

Conclusions An analysis was carried out of the rheological properties of magnesite-phosphate mortars in relation to the density of the sodium hexametaphosphate solution and the grain size distribution of the magnesite powder. The technological properties were found to be at optimum for mortar MF-1 which is characterized by a low-strength coagulation structure and a high degree of mobility.Translated from Ogneupory, No. 1, pp. 40–44, January, 1976.     

高硅型铁尾矿机械活化效果及机理研究

为促进铁尾矿工程应用,以辽宁本溪高硅型铁尾矿为例,研究机械活化方式和活化时间对铁尾矿形貌及活性的影响。通过粒度分析、胶砂试验和石灰吸附测试等,探究机械活化对铁尾矿粒径分布、比表面积、活性指数和火山灰活性的影响;通过X射线衍射和扫描电镜分析,探究胶凝体系的水化反应机理。结果表明:机械活化可以优化铁尾矿粒径,提高颗粒圆度,降低颗粒表面结晶度,且粉磨40~60 min效果最佳;湿磨活化50 min时,活性指数达96.6%,火山灰活性大幅提升,湿磨活化效果显著优于干磨;机械活化促进了铁尾矿与水泥的二次水化反应,提升了胶凝体系性能。     

Microstructural Characterization of Structural Ceramics Using Image Processing and Analysis

Digital imaging and analysis methods are applied to the quantitative study of microstructural changes which occur during hot-pressing of yttria-doped silicon nitride. Effects of processing changes upon the grain growth and microstructural anisotropy are described. Relationships between grain cross-sectional area and mechanical properties are established. It was found that, over the range of processing conditions used, increases in grain size correlated strongly with an increase in fracture toughness. The grain size distribution broadened significantly with hot-press time, resulting in reduced flexural strength. Although no significant change in the mean grain shape factor was observed, the variance in shape factor decreased as the hot-press time was extended.