废旧建筑玻璃制备泡沫玻璃的研究

利用废旧建筑玻璃为原料,以碳酸钙为发泡剂、硼酸为助溶剂,采用模压成型、高温发泡工艺成功制备出了泡沫玻璃,研究了发泡剂含量与发泡温度对泡沫玻璃的体积膨胀率、体积密度、气孔率、抗折强度等性能的影响.结果 表明:在800 ～840℃的发泡温度范围内,随发泡剂含量的增加,泡沫玻璃的体积膨胀率与气孔率先增大后降低,而体积密度和抗折强度先降低后增大,在发泡剂含量为3％,发泡温度在820℃时,泡沫玻璃综合性能良好,其体积膨胀率达476％,体积密度为0.21 g/cm3,气孔率达87.26％,抗折强度为(1.38 ±+0.15) MPa,孔径介于1.7 ～2.2 mm之间.     

发泡法制备孔结构可控的镁质轻质料

利用发泡法在1 580℃保温3 h烧成制备镁质轻质料,并研究泡沫搅拌时间(5、10、15和20 min)、泡沫加入量(每千克料浆中分别加入300、500、700和900 m L)、镁砂粒度(平均粒度0. 3、3. 48、20. 16和40μm)对烧后试样体积密度、显气孔率和耐压强度的影响,并通过SEM分析了其显微结构。结果表明:当泡沫搅拌时间为15 min时,烧后试样的体积密度最小,常温耐压强度最大,显气孔率最大,气孔分布均匀,孔径为20～40μm;随着料浆中泡沫量的增加,烧后试样的体积密度和常温耐压强度减小,显气孔率增加,孔径增大且分布分散;随着镁砂粒度的减小,烧后试样的体积密度减小,常温耐压强度增大,显气孔率增加,孔径减小且分布均匀,气孔壁变薄。     

Al粉加入量对凝胶粉结合铝镁不烧砖力学性能的影响

以各种粒径的棕刚玉、白刚玉(<0.047 mm)、镁砂细粉和α-Al2O3为主要原料,铝凝胶粉为结合剂,研究了铝粉加入量对精炼钢包铝镁不烧砖线变化率、抗折强度、耐压强度、显气孔率、体积密度和高温抗折强度的影响,并借助XRD和SEM研究了不烧砖的物相组成和显微结构.结果表明:随着铝粉量的增加,借助于塑性相成型,不烧砖烘干后的显气孔率减小、体积密度增大,抗折、耐压强度增大;在热处理过程中,铝粉一方面促进烧结,另一方面由于铝粉被氧化导致体积膨胀,并占主导地位,使得不烧砖显气孔率增大,体积密度减小,强度先增大后减小.高温抗折强度随铝粉加入量的增加而增大.     

镁橄榄石骨料的合成及其对镁橄榄石质耐火材料性能的影响

采用XRD分析了镁橄榄石碎矿细粉及其分别经1200～1600℃3h煅烧后的物相组成,研究了煅烧温度和轻烧MgO加入量对镁橄榄石合成骨料显气孔率和体积密度的影响以及合成骨料对镁橄榄石质耐火材料常温物理性能的影响。结果发现:(1)镁橄榄石原料经1200～1600℃3h煅烧后,物相组成没有明显改变,主要以镁橄榄石相为主。(2)随着煅烧温度的提高,合成骨料的显气孔率先降低后增高,体积密度先增大后减小;以不同煅烧温度合成的骨料为主要原料制备的镁橄榄石质耐火材料试样经1600℃3h处理后收缩趋势增大,显气孔率逐渐下降,体积密度增大,抗折强度没有明显变化,耐压强度缓慢增大。(3)随着轻烧MgO加入量的增加,合成骨料的显气孔率先降低后增高,体积密度先增大后减小;轻烧MgO含量为10%时,合成骨料的显气孔率最小,体积密度最大;以添加轻烧MgO的合成骨料为主要原料制备的镁橄榄石质耐火材料试样收缩增大,显气孔率降低,体积密度增大,抗折强度先下降后增高,耐压强度先增高后降低。     

膨润土含量对粉煤灰-赤泥多孔陶瓷性能的影响

以粉煤灰和赤泥为主要原料制备多孔陶瓷。研究了膨润土的加入量对制品显气孔率、抗折强度、体积密度、线收缩率等性能的影响。结果表明,随着膨润土掺量的增加样品的抗折强度和线收缩率增大,但是显气孔率和吸水率降低;膨润土的掺量对样品的孔结构分布和形貌也有明显影响。     

SM高效减水剂及锆英石对耐火浇注料性能的影响

研究了SM高效减水剂对浇注料流动值和力学性能指标的影响,以及添加锆英石粉对耐火浇注料热震后残余抗折强度的影响。结果表明,在试验范围内随SM加入量增大浇注料流动值增大,体积密度增大,显气孔率降低,耐压强度、抗折强度增大;随锆英石加入量增加,热震15次后残余抗折强度先增大后减小。     

膨润土对粉煤灰-城市污泥多孔陶瓷性能的影响

以粉煤灰、城市污泥为主要原料,研究了膨润土的添加量对多孔陶瓷的抗折强度、气孔率、体积密度、线收缩率等性能的影响.结果表明随着膨润土掺量的增加,样品的抗折强度和线收缩率增大,但是显气孔率和吸水率降低;膨润土的掺量对样品的孔结构分布和形貌也有明显影响.     

利用废玻璃研制瓷质砖及陶瓷透水砖

以陶瓷废料,废玻璃和粘土为主要原料研制瓷质砖及陶瓷透水砖,通过对该材料的吸水率、显气孔率、抗折强度、体积密度等性能的测试及SEM分析,结果表明:在合适的工艺参数条件下,可得透水系数为0.10cm/s,压缩强度为12.1Mpa透水瓷砖及瓷质砖。     

长石发泡陶瓷的制备及性能

以长石为原料、SiC为发泡剂,经混料、压制成型、高温发泡等工序制备了长石发泡陶瓷,研究了发泡剂含量与发泡温度对长石发泡陶瓷的体积膨胀率、体积密度、气孔率和力学性能的影响。结果表明,在1160～1200℃的发泡温度范围内,随着发泡剂含量的增加,长石发泡陶瓷的体积膨胀率和气孔率都呈现先增大后减小的趋势,而体积密度和抗折强度则先减小后增大;在发泡剂含量为7%,发泡温度为1180℃时,可获得各项性能优异的发泡陶瓷,其体积膨胀率为258%、体积密度为0.38 g/cm~3、气孔率为78.86%、抗折强度可达3.3±0.26MPa。     

高表面积氧化铝泡沫陶瓷的制备及性能

以活性γ氧化铝粉为骨料、拟薄水铝石溶胶为黏结剂、聚氨酯泡沫海绵为模板,通过挂浆、干燥、烧成等工序制备了高比表面积氧化铝泡沫陶瓷,研究了陶瓷浆料中活性氧化铝含量对氧化铝泡沫陶瓷微观形貌、体积密度、开气孔率、抗折强度和比表面积的影响。结果表明:随浆料中活性氧化铝含量从30%增大到40%时,烧成泡沫陶瓷通孔率逐渐降低、孔径变小、孔筋变粗;体积密度从0.27g/cm~3增加到0.38g/cm~3;开气孔率从89%降低至79%;抗折强度从0.22MPa增大至0.59 MPa;而泡沫陶瓷的比表面积变化不大,约为160m~2/g左右。     

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.     

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…     

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.     

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.     

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。     

用两个形状指数表征粉煤灰颗粒形貌的研究

引用两个形状指数表征颗粒形状的概念,即先将颗粒形状近似为椭圆,再将椭圆图像分离:以圆为基准的颗粒宏观形状指数δ;以光滑椭圆为基准的颗粒轮廓凹凸度,即微观形状指数ζ。分析和发展了近似椭圆模型。并运用图像分析仪对粉煤灰、水泥样品进行实验。结果表明,粉煤灰颗粒的两个形状指数δ和ζ都大于水泥颗粒。证明粉煤灰颗粒的球形度、表面光滑度优于水泥,而且,随着粒径增大,δ和ζ呈下降趋势,表明磨制颗粒越粗。(?)粒形状越不规则。文中还运用近似椭圆模型再现了颗粒的模拟图像。     

典型煤碳燃烧特性研究和数值模拟

本文以三种典型煤的碳燃烧为研究对象，分别采用简单一维沉降燃烧方式和等温加热燃烧方式，实验研究了煤在快速加热条件下，其碳的初期和中，后期燃烧过程。以实验为基础，建立了煤的碳燃烧模型，变工况数值模拟了煤的碳燃烧过程，揭示了煤不同条件下的单颗粒碳燃烧特性。