影响铁精矿K2O、Na2O、SiO2含量的因素分析

用统计分析方法 ,分析了影响精矿K2 O、Na2 O、SiO2 含量的因素 ,并根据分析结论提出了对生产工艺进行定向控制的条件     

铁液洁净度对凝固热力学参数的影响

为了给高洁净钢连铸细晶技术提供相关理论依据，在高温钼丝炉中通过对电解纯铁加金属铝和硅脱氧，获得不同铁液洁净度的试样。利用差热分析法测定了试样在相同冷却速度下的过冷度。利用凝固过程热力学理论研究了铁液洁净度与过冷度、凝固热力学驱动力、形核功和临界晶核半径等的关系。结果表明：随着铁液洁净度的提高，铁液凝固时的过冷度增大，形核所需的凝固热力学驱动力变大，非均质形核功和临界晶核半径减小。     

美国钢铁企业的并购浪潮及特点分析

介绍了最近美国大型钢铁企业发生的主要并购活动。并对这些并购活动的特点进行了分析。     

Model of Primary Austenite Dendrite Structure in Hypoeutectic Cast Iron

Ｉｔｗａｓｒｅｐｏｒｔｅｄ[1] ｔｈａｔｔｈｅｍｉｃｒｏ ｓｔｅｒｅｏｓｔｒｕｃｔｕｒｅｏｆｐｒｉｍａｒｙａｕｓｔｅｎｉｔｅｉｎｃａｓｔｉｒｏｎｃｏｎｓｉｓｔｓｏｆｐｒｉｍａｒｙｓｔｅｍｓａｎｄｓｅｃｏｎｄａｒｙａｒｍｓｔｈａｔ ｇｒｏｗａｃｃｏｒｄｉｎｇｔｏｄｅｎｄｒｉｔｅｃｒｙｓｔａｌｓｂｒａｎｃｈｒｕｌｅ ,ａｎｄｓｏｍｅｏｆｐｒｉｍａｒｙａｕｓｔｅｎｉｔｅｅｖｅｎｈａｖｅｔｈｉｒｄａｒｍｓ .ＭｉｙａｋｅＨｅｔａｌ[2 ]ｐｒｏｐｏｓｅｄａｃｏｎｃｅｐｔｏｆｒｅｇｉｏｎｍｏｄｅｌｂｙｓｔｕｄｙｉｎｇ…     

Study on Oxygen Isotope Fractionation in RE Oxide Minerals

ＳｔｕｄｙｏｎＯｘｙｇｅｎＩｓｏｔｏｐｅＦｒａｃｔｉｏｎａｔｉｏｎｉｎＲＥＯｘｉｄｅＭｉｎｅｒａｌｓＦａｎｇＴａｏ（方涛），ＱｉｕＹｕｚｈｕｏ（裘愉卓）（ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｃｈｅｍｉｓｔｒｙ，ＡｃａｄｅｍｉａＳｉｎｉｃａ，Ｇｕｉｙａｎｇ５...     

老铁矿寻求新发展

云浮市铁矿是个老矿山，在资源减少、设备陈旧、成本增加和效益骤降等困境中，坚持走“一业为主，多种经营”的路子，在革新挖潜的同时，拓展工、商、贸及房地产业等多元化经营，使老矿山旧貌换新颜，多种经营收益已超过矿山总收益的30％。     

Inhibiting and deactivating effects of water on the selective catalytic reduction of nitric oxide with ammonia over MnOx/Al2O3

The effect of water on the selective catalytic reduction (SCR) of nitric oxide with ammonia over alumina supported with 2–15 wt.-% manganese oxide was investigated in the temperature range 385–600 K, with the emphasis on the low side of this temperature window. Studies on the effect of 1–5 vol.-% water vapour on the SCR reaction rate and selectivity were combined with TPD experiments to reveal the influence of water on the adsorption of the single SCR reactants. It turned out that the activity decrease due to water addition can be divided into a reversible inhibition and an irreversible deactivation. Inhibition is caused by molecular adsorption of water. TPD studies showed that water can adsorb competitively with both ammonia and nitric oxide. Additional kinetic experiments revealed that adsorbed ammonia is present in excess on the catalyst surface, even in the presence of water. Reduced nitric oxide adsorption is responsible for the observed reversible decrease in the reaction rate; the fractional reaction order changes from 0.79 in the absence of water to 1.07 in its presence. Deactivation is probably due to the dissociative adsorption of water, resulting in the formation of additional surface hydroxyls. As the amount of surface hydroxyls formed is limited to a saturation level, the deactivating effect on the catalyst is limited too. The additional hydroxyls condense and desorb in the temperature range 525–775 K, resulting in a lower degree of deactivation at higher temperature. A high temperature treatment at 775 K results in a complete regeneration. The amount of surface hydroxyls formed per unit surface area decreases at increasing MnO_x-loading. The selectivity to the production of nitrogen is enhanced significantly by the presence of gas phase water.     

Reactivity of steam in exhaust gas catalysis III. Steam and oxygen/steam conversions of propane on a Pd/Al2O3 catalyst

A 1% Pd catalyst (38% dispersion) was prepared by impregnating a γ-alumina with palladium acetylacetonate dissolved in acetone. The behaviour of this catalyst in oxidation and steam reforming (SR) of propane was investigated. Temperature-programmed reactions of C₃H₈ with O₂ or with O₂ + H₂O were carried out with different stoichiometric ratios S(S =[O₂]/5[C₃H₈]). The conversion profiles of C₃H₈ for the reaction carried out in substoichiometry of O₂ (S < 1) showed two discrete domains of conversion: oxidation at temperatures below 350°C and SR at temperatures above 350°C. The presence of steam in the inlet gases is not necessary for SR to occur: there is sufficient water produced in the oxidation to form H₂ and carbon oxides by this reaction. Contrary to what was observed with Pt, an apparent deactivation between 310 and 385°C could be observed with Pd in oxidation. This is due to a reduction of PdO_x into Pd⁰, which is much less active than the oxide in propane oxidation. Steam added to the reactants inhibits oxidation while it prevents the reduction of PdO_x into Pd⁰. Compared to Pt and to Rh, Pd has a higher thermal resistance: no deactivation occurred after treatment up to 700°C and limited deactivation after treatment up to 900°C, provided that the catalyst is maintained in an oxygen-rich atmosphere during the cooling.     

Catalytic oxidation of sulphide ions to elementary sulphur in aqueous solutions over transition metal oxides

The catalytic activity of a wide range of transition metal oxides in oxidation of sulphide ions by air in aqueous medium was studied. Some specific features of the reaction mechanism on some of the studied oxides were considered. The transition metal oxides are promising catalysts for practical application. Some of these oxides will allow the preparation of catalysts possessing activity comparable to that of the cobalt phthalocyanine based catalysts, popular in industrial practice.     

国产活性炭在合成气净化中的应用

选择国产Ｋ０１活性炭脱除羰基铁、镍，以达到保护铑催化剂并减少副产物的目的。１年的实际应用结果表明：国产Ｋ０１活性炭能够替代进口活性炭在合成气净化中应用。