Carbores P加入量对硅溶胶结合铁沟浇注料性能的影响

为了获得更加环保的Al2O3-Si C-C铁沟浇注料,在w(电熔棕刚玉颗粒)为60%、w(Si C颗粒和细粉)为21%、w(硅灰)为3%、w(α-Al2O3微粉)为3%、w(白刚玉微粉)为10.5%、w(Si粉)为2.5%的基础配方中,分别以质量分数为0、1%、2%、3%和4%的环保型含碳材料Carbores P等量替代白刚玉微粉,外加质量分数为7%的硅溶胶为结合剂,制成Al2O3-Si C-C浇注料,研究了Carbores P加入量对110℃干燥后及1 100和1 500℃烧后试样显气孔率、体积密度、烧后线变化率、常温耐压强度、常温抗折强度和高温抗折强度的影响。结果表明:随着Carbores P加入量的增加,干燥及烧后试样的显气孔率逐渐增大,干燥后试样的体积密度逐渐减小,1 100℃烧后试样的线膨胀率逐渐增大,干燥后试样的常温抗折强度和常温耐压强度以及1 100和1 500℃烧后试样的常温抗折强度变化均不大;1 100和1 500℃烧后试样的体积密度、1 500℃烧后试样的线膨胀率、1 100和1 500℃烧后试样的常温耐压强度、干燥后试样的高温抗折强度等均呈先增大后减小的变化趋势,均在Carbores P加入量为2%(w)时达到了最大。     

Fe2O3对β-SiAlON结合刚玉材料性能的影响

以白刚玉、硅粉、铝粉和α-Al2O3微粉等为原料,在氮化炉中于1460℃原位合成的β-SiAlON-刚玉复合材料,其氮含量(w)为3%,显气孔率为11.8%,体积密度为3.22g.cm-3,耐压强度为106.5MPa。在此基础上,用2%的Fe2O3替代白刚玉,在相同条件下合成的复合材料,其氮含量下降为2.4%,显气孔率和体积密度分别为12.4%和3.21g.cm-3,耐压强度增大为174.5MPa。试样的XRD分析表明,这两个试样的主晶相均为刚玉和z=3的β-SiAlON;未加Fe2O3的试样杂质很少,而加Fe2O3的试样中杂质较多,杂质主要为莫来石,这说明加入的Fe2O3阻碍了材料的氮化。另外,其β-SiAlON相中除了有Si3Al3O3N5外,还有Si4.69Al1.31O1.31N6.69。     

α-Al2O3含量对刚玉-莫来石材料物理性能的影响

以电熔莫来石、板状刚玉为骨料,加入不同量α-Al2O3细粉,在1600℃保温3 h烧成。检测了试样的体积密度、显气孔率、抗折强度、抗热震性,并结合X射线衍射(XRD)、扫描电子显微镜(SEM)和EDAX分析了试样的显微结构。结果表明,试样在经过1600℃烧成后,随着α-Al2O3微粉含量的提高,试样体积密度和高温抗折强度呈先升高后降低的趋势,耐压强度逐渐降低;α-Al2O3微粉含量为8%的刚玉-莫来石材料,经1600℃烧成后α-Al2O3颗粒长大,分布均匀,结合紧密,形成连续的交错网络骨架结构,具有较好的物理性能。     

AlF3对莫来石-刚玉质窑具性能与显微结构的影响

以莫来石(3~1mm)和刚玉(≤1mm)为骨料,以α-Al2O3(3~5μm)、硅线石(≤0.045mm)、硅微粉(3~5μm)、粘土(≤0.045mm)为基质料,分别外加0、9%和12%的添加剂AlF3(d50=12.03μm),成型后分别在1700℃和1725℃保温4h烧成,制得莫来石-刚玉质窑具试样,然后检测烧成后试样的显气孔率、常温耐压强度、常温抗折强度和抗热震性能,并采用扫描电镜分析烧成后试样的显微结构。结果表明随着AlF3含量的增加,烧成后试样的显气孔率逐渐增大;引入AlF3后,烧成后试样的常温耐压强度、常温抗折强度和热震后抗折强度保持率均提高,且以外加9%的最高,外加12%的次之;加入AlF3的试样在1725℃烧成后,有类似晶须状的柱状莫来石形成,这有利于其强度和抗热震性能的提高。     

铝硅混合凝胶对刚玉-莫来石制品性能的影响

按莫来石骨料占65%(质量分数),刚玉和黏土组成的混合粉占35%(质量分数)配料,分别外加占原料总质量4%的水、硅溶胶、铝硅混合凝胶作结合剂,研究了结合剂种类对刚玉-莫来石材料经1 100、1 400和1 600℃分别保温3 h烧后的性能及显微结构的影响,并在此基础上研究了铝硅混合凝胶加入量(分别为1%、2%、3%、4%)及配比(m(Al2O3):m(SiO2)分别为8:2、7:3、4:6)对刚玉-莫来石制品常温性能的影响.结果表明:以铝硅混合凝胶为结合剂的刚玉-莫来石试样,经1 400、1 600℃烧后的常温、高温抗折强度和抗热震性均比仅加硅溶胶或水的好,但显气孔率偏大;当铝硅混合凝胶加入量为2%且m(Al2O3):m(SiO2)=7:3时,烧后试样的常温强度最高.     

利用铝材厂污泥研制刚玉/莫来石/钛酸铝复相材料

本研究以铝型材厂煅烧污泥为主原料,研制刚玉/莫来石/钛酸铝复相材料。本实验主要探讨不同配方对复相材料结构与性能的影响,从而确定较佳的配方。用XRD和SEM分析确定各试样的晶相和结构,应用Rietveld quantification软件计算试样中各晶相的含量,测试各试样性能。实验结果,各试样形成3种晶相:α-Al2O3、Al4.59Si1.41O9.7和Al2TiO5,其中Al4.59Si1.41O9.7是主晶相。分析结果,确定NO.4为最佳的配方,其对应晶相含量:α-Al2O3为15.2%、Al4.59Si1.41O9.7为57.6%、Al2TiO5为27.2%;其对应的抗折强度107.63Mpa,一次热震强度抗折强度保持率为41.51%。     

TiO2加入量对刚玉-尖晶石浇注料性能的影响

以板状刚玉为骨料,电熔白刚玉粉、电熔尖晶石粉、α-Al2O3微粉、纯铝酸钙水泥、金红石型TiO2为基质,按骨料、基质质量比为70:30配料,用金红石型TiO2替代≤0.044 mm电熔白刚玉细粉,其加入量(w)分别为0、2%、4%和6%,加水混匀后振动浇注成25 mm×25 mm×125 mm的试样,于室温下养护24 h后脱模,经110℃24 h烘干后,分别经1 100、1 300、1 500℃热处理3 h后,进行常温物理性能、热态抗折强度、抗热震性的研究,并利用SEM对部分试样在1 400℃下高温抗折强度试验后的断口形貌进行分析。结果表明:(1)1 300和1 500℃烧后试样基质中主要物相为刚玉、尖晶石、钛酸铝和六铝酸钙;随TiO2加入量的增加,TiO2与Al2O3反应生成的钛酸铝衍射峰强度逐渐增加。(2)加入TiO2对1 100和1 300℃烧后刚玉-尖晶石浇注料的显气孔率、体积密度和线变化率影响较小;但使1 500℃烧后浇注料的显气孔率降低,体积密度增加,体积变化从微膨胀到收缩。(3)加入2%TiO2可明显提高浇注料的常温强度,但加入量>4%时明显降低了浇注料的常温强度。(4)加入TiO2对浇注料的高...     

MgO矿化剂对自结合钛酸铝/莫来石复相材料结构和性能的影响

在铝厂污泥,龙岩高岭土和工业二氧化钛合成出的良好稳定性的钛酸铝/莫来石熟料基础上,添加MgO矿化剂进行改性,其能与钛酸铝/莫来石材料形成固溶体,能抑制Al2TiO5的分解,使得钛酸铝/莫来石复相材料在保持低热膨胀系数的同时,较大辐度地提高了材质的机械强度.采用XRD和SEM法表征各试样的晶相和显微结构;各试样中各晶相的含量由用Rietveld Quantification 法确定;测试各试样的性能.从结构与性能分析结果,确定1.5％为MgO的最佳添加量,形成的三个晶相Al2-xMgx+yTi1-yO5-0.5x-y、Al4.59Si1.41O9.70和α-Al2O3分别为68.2％、26.5％和5.3％,对应的抗折强度为45.67 MPa,体积密度为2.95 g/cm3,吸水率为1.81％,气孔率为4.99％,热震后抗折强度保持率为90.0％.     

锆莫来石对Al2O3-ZrO2-C材料性能的影响

以电熔白刚玉、锆莫来石、鳞片石墨、SiC粉和酚醛树酯为原料,通过改变锆莫来石的加入量和粒度制备了7种不同的A l2O3-ZrO2-C试样,主要研究了锆莫来石加入量和试样的粒度组成对A l2O3-ZrO2-C材料的体积密度、显气孔率、常温耐压强度、气孔孔径分布和透气度等性能的影响。结果表明:1)锆莫来石加入量对A l2O3-ZrO2-C材料的体积密度、显气孔率、耐压强度、气孔孔径分布和透气度都有一定的影响,但影响都不大;2)试样的粒度组成对A l2O3-ZrO2-C材料的体积密度和透气度的影响较大,但对显气孔率、常温耐压强度、气孔孔径分布的影响较小。     

α-Al2O3微粉加入量对刚玉干式捣打料性能的影响

为了提高感应炉用刚玉炉衬的服役寿命,以棕刚玉、电熔镁砂、α-Al2O3微粉为原料制备了刚玉干式捣打料,并研究了α-Al2O3微粉加入量(其质量分数为0、1%、2%和3%)对刚玉干式捣打料性能的影响。研究结果表明:经1 600℃热处理后,随着α-Al2O3微粉的增多,刚玉干式捣打料的加热永久线变化呈先减小后增大趋势,体积密度增大,显气孔率相应减小,耐压强度先减小再增大;α-Al2O3微粉加入量为2%(w)时试样的加热永久线变化相对较小,耐压强度减小到22.8 MPa。XRD和SEM分析表明:经1 600℃3 h烧后捣打料中的α-Al2O3微粉反应生成了粒状镁铝尖晶石,晶粒尺寸较小,且分布均匀,有助于捣打料致密度的提高。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

三种煤样燃烧热的测定

本文通过三个厂家提供的三种煤样燃烧热的测定,由测定结果综合得出3号煤样燃烧最完全、燃烧热也最大,是三个煤样中最好的一种。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

小议汽车涂装工艺设计对涂装成本的影响

论述了涂装工艺设计对涂装设备投资、涂装生产成本的影响。     

Measurement of the gradient of viscosity with composition of mixtures of non-ideal gases

A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%.     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

塔设备改造选型的分析

就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后，着重介绍一种新型塔板（导向梯形浮阀塔板）和一种新型填料（波环填料——乾隆帕克）。     

Effect of degree of deacetylation of chitin on the properties of chitin crystallites

In the present article, chitin from crab shell was systematically deacetylated using a NaOH treatment with control of the reaction time. The degree of deacetylation, monitored using solid-state NMR, revealed that the reaction was pseudo-first order. Based on this, swollen and NaOH-saturated particles are proposed as the reaction system. The weight loss of the partially saponified and neutralized samples after HCl hydrolysis increased linearly with the degree of deacetylation. The crystallinity of the samples was found to increase after acid hydrolysis. According to conductimetric titration, the surface charge density of the crystallites, after acid hydrolysis, was found to increase with base treatment time. The effect of surface charge on the formation of a chiral nematic phase, due to the rodlike nature of the crystallites, was explored. These results show that because the contribution of charged particles to the ionic strength was significant the double layer compression was affected, especially since the surface charge density was close to the Manning limit. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:373–380, 1997