环保型建筑陶瓷砖性能与湿法浇注成型研究

以工业废料粉煤灰为主要原料,讨论粉煤灰的大量引入(≥65 wt%)对坯体工艺性能和红外性能的影响。以粉煤灰掺入量达85 wt%为基础配方,探讨高掺量粉煤灰湿法浇注成型的相关工艺。实验结果显示:粉煤灰的增加会提高坯体的弯曲强度和远红外发射率,当粉煤灰掺入量达85 wt%时,坯体弯曲强度达82 MPa,红外发射率达到0.91;湿法浇注成型较传统压制粉料成型能较大程度提高生坯的强度,当加入65 wt%水,4 wt%淀粉,0.04 wt%分散剂和0.6 wt%PVA在60~80℃干燥后生坯强度达到1.48 Mpa,较干压成型生坯强度(0.28 MPa)提高约5.3倍。     

来稿摘要选登

文章从陶瓷坯体的干燥机理开始,综合分析讨论了各种陶瓷原料的"红外活性"及其红外吸收光谱,并通过对不同配方的陶瓷坯体的实际测试,证明了陶瓷坯体在远红外波段有两个较强的吸收谱带,为陶瓷坯体采用远红外干燥的可能性,提供了理论依据.     

陶瓷坯体的干燥与远红外的关系

本文从陶瓷坯体的干燥机理开始,综合分析讨论了不同陶瓷原料的“红外活性”及其红外吸收光谱,并通过对不同配方的陶瓷坯体的实际测试,查明了陶瓷坯体在远红外波段有两个较强的吸收谱带,为陶瓷坯体采用远红外干燥的可能性,提供了依据。     

废玻璃降低日用陶瓷烧成温度的研究

研究废玻璃降低日用陶瓷烧成温度的可能性.以普通陶瓷坯料为基体,外加不同粒度的废玻璃并调整废玻璃的掺加量,经干燥成型制备坯体,干燥后在1100℃～1250℃烧结.通过测定吸水率、电子扫描电镜观察断面形貌确定其烧结程度及致密度,测试其强度进行比较.实验结果表明,陶瓷坯体掺入废玻璃不仅能降低烧成温度还能增加强度,添加9%、120目废玻璃粉的坯体强度增加16.73%.     

粉煤灰-氧化铝多孔陶瓷的制备

粉煤灰主要是来源于火电厂与钢铁厂的一种工业固体废弃物,希望利用廉价的粉煤灰和氧化铝研发出高性能的多孔陶瓷,以应用于环境、冶金、化学等工业领域。利用不同配比的粉煤灰、氧化铝及造孔剂,干压成型得到柱状坯体,经高温烧结,制得多孔陶瓷,并用×RD和SEM分别对其物相结构和表面形貌进行了分析。结果表明,粉煤灰与氧化铝的比约为7：0．9、造孔剂为10％～15％、于1250℃烧结时,可以制备出抗压强度17．3MPa～30．2MPa、显孔隙率30％～48％及孔径大小2～12μm的粉煤灰多孔陶瓷。实验结果将对粉煤灰开发技术的研究具有参考意义。     

粉煤灰空心微珠多孔陶瓷的结构与性能

以粉煤灰和矿粉为原料,制备空心微珠坯体,坯体中粉煤灰含量分别为12.5%(质量分数)、25.0%、37.5%、50.0%,将空心微珠坯体进行堆烧,制备多孔陶瓷。用扫描电子显微镜、X射线衍射仪、X射线荧光光谱仪及电子探针分析仪分析样品的微观形貌和物相组成。结果表明:随着粉煤灰含量的增加,多孔陶瓷体积密度增大。多孔陶瓷的主晶相为硅灰石相,同时含有少量的辉石相。当粉煤灰含量为25.0%、空心微珠坯体在1 000℃烧结时,多孔陶瓷样品体积密度为1.94 g/cm3,抗压强度为163.20 MPa。     

压力对凝胶注模成型95氧化铝陶瓷性能的影响

本文采用低毒的MAM-MBAM凝胶体系代替AM-MBAM有毒体系制备95氧化铝陶瓷,为改善成型后坯体的性能,在凝胶注模成型过程中给予浆料压力.研究发现在压力为0.3 MPa时获得的坯体表面光洁,线收缩率大,体密度高,结构均匀,成品率高,质量好.本文还并研究了压力对95氧化铝陶瓷烧结体线收缩率和体密度以及洛氏硬度的影响.实验结果表明:压力辅助凝胶注模成型所得坯体烧结后性能优于无压直接注模成型坯体,压力为0.3MPa时线收缩率最小,体密度最高可达3.81 g/cm3,洛氏硬度最高.坯体显微结构显示,陶瓷粉料被有机高分子网络很好地粘结在一起,并且压力注模的坯体中陶瓷粉料堆积紧密,结构均匀致密.烧结后,压力注模成型坯体晶粒发育良好,气孔较无压直接注模烧结体少,烧结致密性能优异.     

远红外谷物干燥陶瓷辐射器的研究

确定了锆钛系远红外谷物干燥复合陶瓷辐射板的原料配方.制定了正确的烧结工艺,制作出无变形和开裂的远红外辐射板,并测试了它的陶瓷和红外性能,各项指标均符合国标要求.其辐射光谱与谷物的吸收光谱实现了良好的匹配,其法向全辐射率高达87%.     

负离子抗菌复合陶瓷研究

通过将电气石直接加入陶瓷坯体中,将载银抗菌剂和TiO2通过浸渍复合在坯体表面及坯体通孔表面,制成了负离子抗菌复合陶瓷产品,并分析了该陶瓷的配方、烧结温度和浸泡时间对负离子释放量和抗菌性能的影响,以及利用X射线衍射对该种陶瓷的微观结构进行了研究.     

纳米氧化锆分散液微喷射黏结增材制造氧化锆陶瓷

黏结剂微喷射黏结增材制造技术可成形任意形状陶瓷坯体,但坯体烧结后的致密度和强度低、表面较粗糙。采用纳米氧化锆分散液代替常规有机黏结剂作为喷射溶液,研究纳米氧化锆分散液喷射量对微喷射黏结增材制造氧化锆陶瓷烧结性能的影响规律及其机理。当纳米氧化锆分散液喷射量(体积分数)从0增加至175%时,氧化锆陶瓷烧结线收缩率和表面粗糙度显著减小,其减小幅度分别为6%～8%、57%,而致密度、抗弯强度和硬度明显增加,其增加幅度分别为18.1%、124.0%和187.0%。纳米氧化锆分散液喷射后,纳米氧化锆颗粒填充氧化锆粉层孔隙,提高了氧化锆坯体致密度,从而改善氧化锆陶瓷烧结质量,这为快速制造复杂致密的陶瓷零部件提供了新方法。     

氢气纯度分析方法准确性的探讨

ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l／3为氧气,2／3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中：A一混…     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

HEASUREHENT OF INSTANTANEOUS RATES OF LOSS OF VOIATILE COMPOUNDS DURING DRYING OF DROPS

A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.

Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology.     

茶多酚提取方法进展

本文综述了国内外现有茶多酚提取方法的现状以及近期的研究进展，并对其优缺点进行了评价。这将有助于中低档茶的综合利用和茶多酚的进一步开发应用。     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.     

环氧树脂羟基值测定方法的研究

利用乙酸酐、吡啶和浓硫酸混合的乙酰化试剂测定环氧树脂中羟基值含量的方法具有操作简便、滴定终点明显和分析结果误差小等优点。     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

几种针状焦性能对比

针状焦分石油系和煤系两大类,这主要取决于针状焦的原料来源。在同一系列中由于原料不同和工艺条件不同 ,针状焦的各自性能也不相同。针状焦是生产超高功率石墨电极和高功率石墨电极的主要原料 ,针状焦的性能对石墨电极的质量有至关重要的影响。所以对针状焦性能以及其对石墨电极质量影响的研究十分必要的。以下是常用的几种进口针状焦和国产针状焦的性能对比。１原料性能分析对比原料试样包括４种针状焦 ,其中两种为进口针状焦：三菱针状焦和新日化针状焦;另两种为国产针状焦：鞍山针状焦和锦州针状焦。其中除锦州针状焦是石油系针状焦外…     

聚酰亚胺的合成法

本文评述了缩聚型聚酰亚胺的主要合成方法和近年来国际上在合成中所做的探索。