Correlations for liquid-phase mass transfer coefficients in bubble column reactors with newtonian and non-newtonian fluids

The earlier work of Calderbank and Moo-Young (1961) dealing with the liquid-phase mass transfer coefficient in gas-liquid dispersions is examined. Their well-known empirical correlations for small and large bubbles which are free to move under gravity are theoretically derived. The analyses are based on the approach for natural convection mass transfer, and include the case where the fluid is non-Newtonian. The predictions of the models are compared with reported experimental data and correlations.     

微量元素对ZrO_2基陶瓷显微结构的影响

本文在常压固态烧结条件下,通过掺加3mol%Y_2O_3和微量氧化物作为晶粒稳定剂和晶粒生长阻碍剂制备出超细化,高密度的四方ZrO_2多晶陶瓷。通过密度测定、X射线衍射、扫描电镜和透射电镜等测试方法分析了微量氧化物CuO,Fe_2O_3和SiO_2对ZrO_2基陶瓷显微结构的影响。     

烧结对 TiC-堇青石复相陶瓷导电性能的影响研究

用相复合技术制备了导电化陶瓷。通过比较不同工艺参数组合条件下制备的样品的导电性能，发现烧结致密化不是影响样品导电性的主要因素。通过高温烧结过程，改善导电相颗粒的接触状况，降低其间接触电阻，是改善样品导电性的最有效手段。     

Microstructural Changes in Liquid-Phase-Sintered Silicon Carbide during Creep in an Oxidizing Environment

The knowledge of the microstructural evolution during exposure to high temperatures is important to understanding the mechanisms responsible for the creep resistance of silicon carbide (SiC) ceramics. This includes not only the phase transformation of the SiC grains, but also the phase transformations of the oxynitride grain-boundary phases. For this study, a series of SiC specimens were prepared with varying molar ratios of AlN-Y₂O₃ additives. Increased creep resistance was observed in specimens with an additive system containing a 2:3 molar ratio or 60 mol% Y₂O₃. A continuous oxide layer of Y₂Si₂O₇ formed at the surface during elevated temperature testing in air. No blistering or cracking was observed in this oxide coating. Further increase of the creep resistance was achieved by a post-sintering nitrogen anneal.     

包钢烧结配加澳矿粉的试验研究

通过实验室试验和工业试验，得出包钢烧结配入澳矿粉后，能提高烧结产量，改善烧结矿冶金性能。工业试验结果得出，配入15％澳矿粉后，烧结增产5．6％，高炉利用系数得到提高，入炉品位得到提高，同时降低了入炉焦比、矿比、渣比，为炼铁系统带来较大的综合经济效益。     

An effective catalyst,Cu-B2O3/SiO2, for hydrogenolysis of methyl formate and one-step synthesis of methanol in slurry-phase with potassium methoxide

Some chromium-free copper-based catalysts are tested for the gas-phase hydrogenolysis of methyl formate, in which Cu-B₂O₃/SiO₂ catalyst is identified to be the most promising. The behaviors of Cu-B₂O₃/SiO₂ catalysts are also examined in the slurry-phase hydrogenolysis of methyl formate, along with a discussion of the promoting effect of B₂O₃. Also, Cu-B₂O₃/SiO₂ is used with potassium methoxide as a co-catalyst for the carbonylation of methanol to regenerate the potassium methoxide from potassium formate and potassium methyl carbonate. Moreover, the slurry-phase one-step synthesis of methanol is studied using KOCH₃/Cu-B₂O₃/SiO₂ mixed catalyst under relatively mild conditions.     

济钢烧结矿的自动化检验

分析了济钢烧结矿现有检验工艺及存在的问题 ,针对检验工艺过程提出了自动化改造方案 ,该系统设备简单、造价低、检测数据直观、快捷、连续、精确 ,可直接指导生产     

Activity of Gold Catalysts in the Liquid-Phase Oxidation of O-Hydroxybenzyl Alcohol

Gold catalysts prepared by impregnation of HAuCl₄ on Fe₂O₃, ZnO, CaO, and Al₂O₃ and aged in a solution of Na₂CO₃ (IWI/Na₂CO₃ method) are able to catalyze the oxidation of o-hydroxybenzyl alcohol (salicylic alcohol) under mild conditions. The reaction rate is even higher than that using analogous catalysts prepared by co-precipitation. Salicylic aldehyde is the main reaction product with a selectivity >90% at 90% conversion. The influence of the reaction conditions on the catalytic activity is also discussed.     

熔炼Al-Li合金用6t无芯工频感应炉炉衬寿命的探讨

论述了熔炼Ａｌ－Ｌｉ合金用６ｔ工频炉的炉衬材料　、打结方式、　烘烤、烧结对炉衬寿命的影响，用该方式制作的　　　　炉衬在生产中取得了良好的效果。     

MgCl2溶液对烧结矿低温还原粉化率的影响

试验测定了 Mg Cl2 溶液不同浓度和喷洒量对济钢现有原料条件下烧结矿低温还原粉化率 (RDI)和还原度 (RI)的影响。结果表明 :每 5 0 0 g烧结矿喷洒 10～ 2 0 m L浓度为 1.0 %～ 3 .5 %的 Mg Cl2 溶液 ,能显著降低烧结矿的 RDI,且还原度不受影响 ,以 5 0 0 g烧结矿喷洒浓度为 2 .5 %的 Mg Cl2 溶液 10 m L综合效果最佳 ,可使烧结矿的 RDI从 3 6%降至 4.4%。