基于STEM理念的高中化学实验探究——以“氢氧化铝制备”实验为例

将STEM理念融入化学实验中,有助于培养新时代全面发展的应用型人才,推动中国素质教育的落实与发展。STEM理念下的实验教学,既是化学学科的组成部分,又是化学教学的具体体现。在"氢氧化铝制备"实验教学中,应选择最佳实验方案,培养学生动手能力,画出反应关系图示,培养学生发散思维,罗列实验知识要点,培养学生的良好习惯。在教学中,充分认识到将STEM理念融入高中化学实验教学的必要性。

高纯氧化铝制备方法和生产现状研究

氧化铝生产设备经常与高腐蚀性物质接触,并且全年暴露于高温和高压下。腐蚀程度非常严重。因此,为了降低生产设备的腐蚀指数,开展了氧化铝厂生产设备的腐蚀防护技术。探索。简要介绍了酸铝的生产工艺,分析了铁杂质影响铝盐结晶的机理。总结了国内外沉淀,萃取,树脂法等酸性溶液铝铁分离技术的研究进展,比较了它们的优缺点,以及除铁技术的未来发展前景,提供了一定的参考和认识。氧化铝除酸工艺中除铁技术突破的灵感来源。

氧化铝陶瓷的制备与应用

氧化铝陶瓷是一种以氧化铝（Al2O3）为主体的陶瓷材料,用于厚膜集成电路。氧化铝陶瓷有较好的传导性、机械强度和耐高温性。需要注意的是需用超声波进行洗涤。

基于碰撞声音的氧化铝熟料质量检测系统设计

构建了一个基于碰撞声音的氧化铝熟料质量检测系统.系统运用2440开发板采集并通过网络发送成品熟料与滚筒窑撞击所产生的声音数据,在接收端通过分析采集到的声音文件频谱、幅度等数据特点,区别出熟料的3种状态:正常、过烧、欠烧,从而为生产过程自动化提供了相应的依据.

焙烧法制备氧化铝分解杂质的影响规律

随着中国社会经济的不断发展及科学技术的不断提升,氧化铝材料制备技术具有十分广阔的发展前景。为了提高制备氧化铝的质量,减少制备氧化铝分解的杂质。针对这一问题,提出焙烧法制备氧化铝分解杂质的影响规律的研究。分别探究焙烧温度及焙烧时间对制备氧化铝分解杂质的影响。致力于高效利用好这一资源,同时为氧化铝材料的发展提供技术支持,得出基于焙烧法最佳制备氧化铝分解杂质的工艺条件。

氧化铝生产过程中流量仪表的选择和应用对比

氧化铝的在工业领域的作用广泛,主要用于主要用与铝锭、定型或不定型耐火材料、耐火浇注料结合剂、耐磨磨具、高纯耐火纤维、电子陶瓷、结构陶瓷、特种钢、工艺玻璃、色料等,日常生活中其实也能经常看见它的声影,氧化铝的制备工艺较为复杂,并且各道工序之间的连续性要求很高,物料之间的循环也较为频繁,因此,物料的流量计量环节决不可马虎,建设单位正确的选取流量仪表可以有效计量物料流量,目前单位上主流的氧化铝制备一般采用是碱式制备法,其又可以分为“拜耳法”,“烧结法”以及“联合法”等多道工序。本文主要讨论氧化铝在碱式制备法的生产过程中所用到的流量仪表的选择以及不同类型的流量仪表的作用。

微波技术在催化材料制备领域的研究进展

综述了近年来微波技术在催化材料领域应用研究的新进展,包括微波在分子筛和氧化铝制备、活性组分的负载及催化剂干燥等方面的应用。

谈《制备氢氧化铝的实验方案设计》的教学设计

新一轮基础课程改革的重点之一，就是建构起学生自己动手实践、自主探索与合作交流的学习方式，逐步改变教师、课堂和书本为中心的局面，促进学生创新意识与实践能力的发展。

Preparation of Alumina Binder-Added PtSnNa/AlSBA-15 Catalyst for Propane Dehydrogenation

Abstract： The present article compares the propane dehydrogenation performance of alumina binder-added PtSnNa/ A1SBA-15 catalysts prepared via three different procedures in comparison with the performance of a binder-free PtSnNa/ AISBA-15 catalyst. All these catalysts have been investigated by reaction tests and some physico-chemical characterizations such as BET, H2 chemisorption, catalytic grain crushing strength, NHa-TPD and TPO analyses. Test results showed that the addition of alumina binder could enhance the mechanical strength of catalyst evidently. Moreover, the different preparation procedures not only modified the characteristics of both acid and metal functions but also affected the coke deposition on the catalysts. Among these catalysts studied, the catalyst prepared by impregnation followed by the agglomeration of alumi- na binder had exhibited the highest catalytic activity and stability compared with other catalyst samples undergoing different preparation procedures. The possible reason may be attributed to the highest metallic dispersion and the strong interactions among Pt, Sn and the support.

Preparation of Alumina Abrasion-Resistant Ceramic Grinding Ball with Spent FCC Equilibrium Catalyst

The chemical composition, structure and thermal stability of the spent FCC equilibrium catalyst from an oil refinery were characterized by XRD, FT-IR, DTA-TG, BET, complete chemical analysis, SEM, and XRF. The spent FCC equilibrium catalyst, clay, barium carbonate, and talc were used as the main raw materials to prepare the alumina abrasion-resistant ceramic balls to be used in the powder grinding mill for manufacture of architecture tiles. The results showed that after proper formulation study, the spent FCC equilibrium catalyst could replace industrial alumina to prepare high performance grinding balls. Meanwhile, the various performance indices of the grinding ball could meet the quality standard for similar products, and additionally, the energy saving effect was achieved in the operation of the grinding section, resulting in a successful comprehensive utilization of solid wastes.

Preparation and sintering properties of zirconia-mullite-corundum composites using fly ash and zircon

Zirconia-mullite-corundum composites were successfully prepared from fly ash,zircon and alumina powder by a reaction sintering process.The phase and microstructure evolutions of the composite synthesized at desired temperatures of 1 400,1 500 and 1 600°C for 4 h were characterized by X-ray diffractometry and scanning electronic microscopy,respectively.The influences of sintering temperature on shrinkage ratio,apparent porosity and bulk density of the synthesized composite were investigated.The formation process of the composites was discussed in detail.The results show that the zirconia-mullite-corundum composites with good sintering properties can be prepared at 1 600°C for 4 h.Zirconia particles can be homogeneously distributed in mullite matrix,and the zirconia particles are around 5μm.The formation process of zirconia-mullite-corundum composites consists of decomposition of zircon and mullitization process.

Preparation and Characterization of γ-Al2O3 by Polyaluminum Chloride with High Al13 Content

In this paper a polyaluminum chloride solution with high Al13 content was prepared and used as raw material for preparation ofγ-Al2O3.The texture and crystalline phase of the prepared alumina samples were characterized by energy dispersive X-ray spectroscopy(EDX) ,X-ray diffraction,transmission electron microscope(TEM) and nuclear magnetic resonance(NMR) analyses.The effects of alkaline solution and calcination temperature were investigated.The results showed that alkaline solution including NH3·H2O and NaOH had little effect on the alumina sample formation.The impurities of NH4Cl and NaCl in solution can be removed through repeated washing by EDX analysis.Calcination temperature had a significant effect on alumina crystal phase.The alumina sample can transform completely toγ-Al2O3 in the subsequent heating from 600°C to 800°C.It is very interesting that Al13 can be existed inγ-Al2O3 phase even after calcinations.The results indicate that polyaluminum chloride with high Al13 content is an effective material to prepareγ-Al2O3.

Preparation and Characterization of Alumina Membranes on Capillary Supports： Effect of Film-coating on Crack-free Membrane Preparation

Ceramic capillary membrane has received much attention due to its relatively high pack density and favorable mechanical strength.However,it is difficult to prepare capillary membrane on its thin support by a dip-coating method.In this study,alumina microfiltration membranes were prepared on the inner surface of alumina capillary support(outer diameter 4 mm,inner diameter 2.5 mm)by a dip-coating method.Scanning electron microscopy(SEM)observation,gas bubble pressure(GBP)method and membrane permeation test were carried out to evaluate membrane performance.Two major effects in preparation of crack-free membrane,capillary filtration and film-coating,upon the thin support were studied.The as-prepared crack-free membrane presents a narrow pore size distribution,a mean pore size of about 0.6μm and a high pure water flux of 86000 L·m -2 ·h -1 ·MPa.It is proved that the membrane thickness should be sufficiently large to overcome the defects of support surface,but it is only one of the prerequisites for the formation of crack-free membrane.Furthermore,it is demonstrated that the capillary filtration effect is greatly restricted for thin capillary support with the dip-coating method and the film-coating effect plays a crucial role in the formation of crack-free membrane.

Preparation of Core-Shell Composite of Y@Mesoporous Alumina and Its Application in Heavy Oil Cracking

A well core-shell composite of Y@meso-Al with a mesoporous alumina shell and a Y zeolite core was synthesized. The mesoporous alumina shell has a wormhole-like structure with large mesopores. The prepared catalytic cracking catalyst using this composite has exhibited excellent catalytic performance for heavy oil cracking thanks to its favorable physicochemical properties, such as high surface area, large pore volume and outstanding acid sites accessibility for large molecules provided by the composite. In comparison with the reference catalyst using pure Y zeolite, the oil conversion achieved by the above-mentioned catalyst increased by 2.73 percentage points, while the heavy oil yield and coke yield decreased by 2.23 percentage points and 1.28 percentage points, respectively, with the light oil yield increasing by 2.27 percentage points.

Fabrication and Characterization of Alumina/CNTs Nanocomposite Powders, by CCVD Method and Investigation of the Parameter Involved

Ceramics in general and particularly alumina （Al2O3） are important materials in various industries, but the main problem with these materials is related to some of their mechanical properties including low resistance against mechanical shock （hardness-toughness）, which makes them to be so brittle, and possession of high degree of porosity which reduces their strength and gives them fragile characteristics. Researchers report indicates that the presence of the second phase with suitable properties can improve some of the mechanical properties of these materials and optimize their characteristic. Carbon nanotubes with unique physical characteristics such as large aspect ratio, high strength and Young＇s modulus and improved thermal properties could be suitable candidates for this purpose. In this study, the growth of multi wall carbon nanotubes （MWCNTs） on the alumina support as the matrix of the composite has been carried out, using catalytic chemical vapor deposition （CCVD） method in which the iron nanoparticles has been selected as catalyst materials. Ethylene gas is used as feed materials for carbon source and argon as the carrier gas. In order to achieve a more comprehensive results, we have investigated the effects of some fabricating parameters like catalyst particle size, its weight percentage related to support material, alumina and to the some synthesizing temperature gases flow rate. Fabricated ceramics composites samples structures were analyzed using SEM images as well as Raman scattering spectra and X-ray diffraction pattern.

Direct spray pyrolysis of aluminum chloride solution for alumina preparation

The effects of pyrolysis mode and pyrolysis parameters on Cl content in alumina were investigated, and the alumina products were characterized by XRD, SEM and ASAP. The experimental results indicate that the spray pyrolysis efficiency is higher than that of static pyrolysis process, and the reaction and evaporation process lead to a multi-plot state of the alumina products by spray pyrolysis. Aluminum phase starts to transform into γ-Al2O3 at spray pyrolysis temperature of 600 °C, which is about 200 °C lower than that of static pyrolysis process. The primary particle size of γ-Al2O3 product is 27.62 nm, and Cl content in alumina products is 0.38% at 800 °C for 20 min.

Preparation High-Temperature Behavior of Conversion Coating of Alumina Film on FeCrAI （Ce） Stainless Steel

FeCrAI （Ce） stainless steel was functionalized by a conversion treatment in order to allow alumina by diffusion coatings with strong interfacial bonding. The very porous conversion coating produced in a pack aluminization technique had excellent adhesion and was conductive enough to permit conditions favorable for the precipitation of alumina oxyhydroxide during aluminum diffusion coatings. In this work, the bed was prepared as a mixture of A1, NH4C1 and A1203. In the high-activity bed were heat-treated at 1,173 K in an atmosphere made up of team with subsequent air-cooling. The effect of the bed content on the coating was examined. With the high-activity, the desired Fe2Al5 was formed as the outermost coating layer. The coating presented chemical composition gradients suitable for strong adhesion. The improvement of the thermal oxidation behaviour was studied at 1,373 K. Two different aqueous environments, which are （1） NaC1 and （2） H2SO4, are employed for using the technique of potentiodynamic polarization curve. The obtained experimental electrochemical parameters （Ecorr, Jcorr etc,） were used to compare the corrosion resistance of the tested steel state complemented by MEB （electronic scanning microscopy） in combination with dispersive analysis X in energy （EDS） or X ray diffraction indicated that the elements concentration maximum was located in the vicinity of the interface especially in the FeCrAI （Ce） coated by spherical A1203 powder. These results an discussed in terms of an addition effect on the development of the microstructure of oxide films.

Preparation and Characterization of Nanosized Al-MCM-41 Using Different Silica Sources

Silica sources influence different aspects of Al-MCM-41 product. The crystallinity of nanosized Al-MCM-41 zeolites prepared crystallization and lead to change in the properties of the final from precursors mixtures containing different silica sources, e.g. tetraethylorthosilicate （TEOS）, colloidal silica （CS）, silicic acid （SA） and fumed silica （FS） have been studied. The produced samples are investigated using XRD, SEM, FT-IR, pyridine adsorption and N2 physisorption. XRD results show that the products obtained from different silica sources are in Al-MCM-41 phase. SEM results show that silica sources influence the produced Al-MCM-41 shape. Using silicic acid leads to formation of spherical crystals, TEOS gives cubical crystals, colloidal silica forms spherical crystals with smaller aggregated, and fumed silica gives rounded crystals. N2 physisorption results show that silica sources influence pore-diameter and pore-volume of the produced Al-MCM-41 ; the pore diameter of the produced Al-MCM-41 in case of colloidal silica, TEOS, fumed silica, and silicic acid are 12, 20, 15, and 17A respectively. Also, the pore volume of the produced AI-MCM-41 in case of colloidal silica, TEOS, fumed silica and silicic acid are 0.78, 0.71, 0.76, and 0.8 cm^3/gm, respectively.

Magnetic nanowires fabricated by anodic aluminum oxide template—a brief review

Anodic aluminum oxide （AAO） with highly ordered nanoscale pores which are monodisperse and mutually parallel can be produced through a self-organized electrochemical process. Subsequent deposition of materials into the nanopores produces AA0 embedded nanowire arrays. Whilst the templates can be further removed to obtain free individual nanowires, the em- bedded nanowires form an interesting nanocomposite structure. Recent research activities on the fabrication and characteriza- tion of AAO template based magnetic nanowires are reviewed in this article. Studies of specific systems are given as an exam- ple of the research in the area.

Al_2O_3-TiO_2 composite oxide films on etched aluminum foil fabricated by electrodeposition and anodization

Ti species have been deposited on low-voltage etched aluminum foils by a simple electrochemical method using a Ti anode as Ti source in a Ti-free I2-dissolved acetone solution. After annealing at 500-600℃ in air, an Al2O3-TiO2 composite oxide film was formed on the surface of the etched aluminum foil by anodizing galvanostatically in an ammonium adipate solution. The effects of I2 concentration in the acetone solution, applied anode voltage, electrolysis time, and annealing temperature on the specific capacitance of the aluminum anode foils were investigated. The TiO2-deposited specimens prepared by applying a po-tential of 50V for 3 min in 2.5m MI2-added acetone solution followed by annealing at 550℃ after anodization exhibited the highest specific capacitance, with an enhancement of 22% compared with pure etched aluminum foil specimens. The electro-deposition process and the change of the anode voltage during the anodization were analyzed.