环保型快速烧结转炉大面修补料的研制及应用

为了减少对环境的污染,提高转炉大面修补料的使用寿命,采用中档镁砂、电熔镁砂为主要原料,引入结合剂、助烧剂、防氧化剂,多元醇为助流剂,环保无烟油类物质作为润湿剂制备了修补料。研究了助烧剂(铁红粉、Al粉和镁橄榄石细粉)、防氧化剂(Al粉、Si粉和Si C粉)及结合剂(高温改性沥青、中温改性沥青)的种类对转炉大面修补料性能的影响。结果表明:以中档镁砂、电熔镁砂为主原料,0.5%(w)的Al粉和1.5%(w)的Si粉复合作为防氧化剂和助烧剂,高温改性沥青与中温改性沥青分别为8.5%、4%(w)作为结合剂时,辅以少量的液体润湿剂和助流剂生产的转炉大面修补料,其环保性好,能快速烧结,强度高,寿命长(平均寿命超过34炉)。     

不同添加剂加入量对Al_2O_3-SiC-C砖性能影响

为进一步提高Al_2O_3-SiC-C砖的性能,以≤5mm的均化矾土料、≤5mm的板状刚玉、≤1mm的碳化硅、0.044mm的α-Al_2O_3微粉和≤0.154mm的石墨等为原料,以酚醛树脂为结合剂制备了Al_2O_3-SiC-C不烧砖。研究了电熔镁砂粉、叶蜡石粉或红柱石粉的加入量(w)皆分别为1%、2%和3%时对试样各项性能的影响,并采用国标对220℃保温24h后试样的各项性能进行检测。结果表明:在Al_2O_3-SiC-C砖中添加少量电熔镁砂粉、红柱石粉、叶蜡石粉可提高试样的高温抗折强度和抗热震性能,加入1%(w)电熔镁砂粉的试样高温抗折强度最大,加入1%(w)红柱石粉的试样抗热震性最好;添加1%(w)电熔镁砂粉可减少熔渣对均化矾土的侵蚀,明显提高试样的抗渣侵蚀性能。综合考虑,加入1%(w)电熔镁砂粉的试样性能最佳。     

转炉用环保型水结合镁质修补料的流动性研究

为改善转炉修补料对环境和工人身体造成的危害,以镁砂骨料(5～3、3～1和≤1 mm)和细粉(≤0.088mm)、SiO2微粉、SiC(≤1 mm)、α-Al2O3微粉、球状SiO2、聚苯乙烯空心球为原料,制备了环保型水结合镁质修补料,并研究了SiC加入量(质量分数,分别为0、1%、2%、3%和4%)、球状SiO2外加量(质量分数,分别为0.04%、0.08%、0.16%、0.24%)、聚苯乙烯空心球外加量(质量分数,分别为0.05%、0.1%、0.2%和0.3%)对该修补料常温和高温(1 000℃)流动性的影响。结果表明:(1)SiC加入量(w)从0至1%时,修补料的常温与高温流动性基本不变,加入量继续增加,则流动性明显降低。(2)随着球状SiO2外加量的增加,修补料的常温和高温流动性均先增加后降低,当其外加量(w)分别为0.08%和0.24%时,修补料的常温和高温流动性最好。(3)随着聚苯乙烯空心球外加量的增加,修补料常温流动值先增大到一定值后保持不变,高温流动性先增加后降低,当外加量(w)为0.2%时,高温流动性最好。     

分散剂及氧化铝微粉对钢包用Al_2O_3-MgO浇注料施工性能的影响

为了提高Al_2O_3-Mg O浇注料的施工性能,以板状刚玉颗粒(粒度分别为5~3、3~1、≤1 mm)和细粉(粒度≤0.074 mm)、电熔镁砂(粒度≤1 mm)、活性氧化铝微粉(PFR40、PBR和CL)、煅烧氧化铝微粉(AC34B5和CT)为主要原料,以铝酸钙水泥(Secar 71)为结合剂,以聚羧酸类减水剂WS、FS和AD为分散剂,制备了Al_2O_3-Mg O浇注料。研究了分散剂种类和外加量[分别为0.4%(w)的WS、0.2%(w)的FS和1%(w)的AD],单一活性氧化铝微粉种类(分别为PFR40和PBR),以及复合氧化铝微粉种类(分别为PFR40-AC34B5复合粉和CL-CT复合粉)及其复合比例(质量比,均从9/0逐渐减小至3/6)对浇注料的流动值及烘干后试样的显气孔率、体积密度、常温抗折强度和常温耐压强度的影响。结果表明:1)在加入单一氧化铝微粉PBR或PFR40时,外加0.4%(w)WS的浇注料的流动性能及烘干后试样的综合性能比外加0.2%(w)FS或1%(w)AD的好。2)加入PFR40-AC34B5复合粉的浇注料的流动值比加入CL-CT复合粉的浇注料的略大;随着PFR40与AC34B5或CL与CT复合比例的减小,浇注料的流动值及烘干后试样的致密度均呈减小趋势,烘干后试样的强度变化不大;但考虑到活性氧化铝微粉的价格较高,应选择合适的复合比例。     

21R(AlN多型体)结合镁质耐火材料的制备及性能研究

先以粒度≤1mm的电熔镁砂颗粒为骨料,以Al粉(纯度99%,粒度≤0.088mm)、活性SiO2微粉(w(SiO2)≥98.3%)和电熔镁砂细粉(≤0.088mm)为基质,保持骨料含量为65%,基质组成为35%不变,变动基质中SiO2微粉与Al粉总量分别占5%、10%、20%和30%,配制了四种不同设计量的21R(AlN多型体)结合镁质耐火材料试样,分别于1400℃、1500℃和1600℃保温3h氮化烧成。研究了材料的烧结性能、物相组成和显微结构。然后在此基础上,将上述配方中65%≤1mm的电熔镁砂骨料用40%3～1mm的电熔镁砂和25%≤1mm的电熔镁砂骨料替代,于1500℃氮化烧成后,研究了材料的抗热震性、抗铁水侵蚀性及抗渣渗透性。结果表明:(1)通过氮化反应可以直接制备21R(AlN多型体)结合镁质耐火材料;(2)21R(AlN多型体)的生成与实际反应温度和反应过程中的液相量有关,此过程中伴随着大量的尖晶石生成反应和一些气相反应;(3)经1500℃氮化处理制得的含21R(AlN多型体)的镁质耐火材料具有良好的抗热震性、抗铁水侵蚀性及抗渣渗透性。     

α-Al2O3及亚白刚玉粉对镁质浇注料物理性能的影响

以高纯镁砂(8～5mm,5～3mm,3～1mm)和电熔镁砂(≤1 mm)为骨料,电熔镁砂细粉、α-Al2O3微粉、亚白刚玉粉、镁铝尖晶石细粉及uf-SiO2微粉为基质,按骨料:细粉=70:30进行配制镁质浇注料.实验中用5%、10%、15%、20%的α-Al2O3与亚白刚玉粉组成的混合物取代等量的镁砂细粉,研究了添加物对镁质浇注料物理性能的影响.     

电熔镁砂加入量对刚玉-尖晶石轻质隔热材料性能的影响

以α-Al2O3细粉(≤74μm)、α-Al2O3微粉(d50=2μm)为主要原料,加入5%(w)的ρ-Al2O3微粉(d50=5μm)为结合剂,外加0.3%(w)的发泡剂和2%(w)的六偏磷酸钠减水剂,在1 550℃3 h煅烧后原位制备了刚玉-尖晶石轻质隔热材料,研究了电熔镁砂加入质量分数(0、5%、10%和15%)对刚玉-尖晶石轻质隔热材料物理性能、热导率及显微结构的影响。结果表明:随着电熔镁砂加入量的增加,试样的体积密度逐渐减小,强度先减小后增大,烧后线变化和重烧线变化(1 550℃3 h)由收缩逐渐表现为膨胀,试样在300～900℃下的热导率均降低;通过发泡法制得的刚玉-尖晶石轻质隔热材料气孔分布均匀,呈球形,且随着电熔镁砂加入量的增加,试样的结构疏松,微孔数量增加,但其对大孔的影响较小。综合考虑试样的各项性能,认为电熔镁砂适合的加入质量分数为15%。     

镁质弥散型透气砖高温抗折强度的研究

本文采用四因素三水平正交设计表,研究了不同加入量电熔镁砂(0.2～0 mm)(质量百分含量,下同)(0％、3％、6％)、α-Al2O3微粉(0.044 mm,5％、8％、10％)、电熔镁砂细粉(0.044 mm,2％、4％、6％)和Cr2 O3细粉(0.044mm,0％、1％、2％)对中间包镁质透气砖高温抗折性能的影响.研究结果表明:在实验条件下,四种材料对镁质透气砖高温抗折强度的影响大小顺序是:电熔镁砂(0.2 ～0 mm)＞工业氧化铬粉＞电熔镁砂细粉＞α-Al2 O3微粉;其中(0.2～0 mm)电熔镁砂和Cr2O3粉对镁质透气砖的高温抗折强度有显著的影响,电熔镁砂细粉对镁质透气砖的高温抗折强度有一定的影响,而α-Al2O3微粉的影响则很小.从镁质透气砖的高温抗折强度来考虑:方案A3B2C2D2为最佳的方案.     

SiO_2微粉加入量对铝镁质湿法喷补料性能的影响

为改善铝镁质喷补料的施工流动性,以72%(w)的板状刚玉,6%(w)的电熔镁砂,以及总量为22%(w)的氧化铝微粉、板状刚玉微粉和纯铝酸钙水泥制备了铝镁质湿法喷补料,并研究了SiO_2微粉加入量(外加质量分数分别为0、0.2%、0.5%、1.0%、1.5%、2.0%和2.5%)对其性能的影响。结果表明:1)当SiO_2微粉加入量为1%~2%(w)时,喷补料具有较好的流动性和泵送性能;2)添加2.5%(w)SiO_2微粉的试样经1 600℃热处理后生成少量霞石,将会降低材料的高温性能;3)110℃烘干后试样的强度随SiO_2微粉加入量的增加而升高,1 600℃处理后的试样强度随SiO_2微粉的增加而显著增大;4)当SiO_2微粉加入量为1.5%(w)时,试样1 600℃烧后的线膨胀率最小;5)试样的高温抗折强度随着SiO_2微粉加入量的增加逐渐下降,少量SiO_2微粉的加入对抗渣渗透有利。综合考虑,铝镁质湿法喷补料中SiO_2微粉加入1.5%(w)最佳。     

烧成温度和气氛对Al_2O_3-Cr_2O_3材料显微结构的影响

为探讨烧成气氛和温度对低铬Al_2O_3-Cr_2O_3耐火材料性能的影响,以w(Cr_2O_3)≤20%的Al_2O_3-Cr_2O_3耐火材料纯基质为研究对象,将质量分数为50%的电熔Al_2O_3细粉、10%的电熔Cr_2O_3细粉、10%的电熔Cr_2O_3微粉和30%的烧结α-Al_2O_3微粉,外加3%(w)的PVA水溶液为结合剂配料后压制成圆片试样,然后分别在空气气氛或埋炭气氛中于1 450、1 550和1 650℃保温3 h烧成,并研究烧成温度和气氛对烧后试样显气孔率、体积密度和显微结构的影响。结果表明:随着烧成温度的升高,试样的显气孔率下降,体积密度升高。显微结构分析发现,无论是空气气氛还是埋炭气氛,随着温度的升高,铝铬固溶体晶粒逐步发育长大,形成连续多孔的网络骨架结构;空气气氛下Cr~(3+)更易迁移扩散,固溶反应较为充分,烧成试样形成的铝铬固溶体晶粒更为粗大、结构连续性好。因而,空气气氛下1 650℃烧成更有利于改善Al_2O_3-Cr_2O_3材料的性能。     

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。     

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.     

我国聚碳酸酯工业发展概况

介绍我国聚碳酸酯生产能力和消费需求,对聚碳酸酯在信息工业中的应用作了简短介绍     

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。     

Effect of degree of deacetylation of chitosan on the kinetics of ultrasonic degradation of chitosan

The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003     

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%.