材料期刊网

Effect of Basicity and Alumina-Silica Ratio on Formation of Silico-Ferrite of Calcium and Aluminum

ZHANG Fang , AN Sheng-li , LUO Guo-ping , WANG Yi-ci

钢铁研究学报(英文版)

Abstract： Baivumebo iron ore is special magnetite containing fluorine, kalium and sodium elements, and the main raw material for ironmaking of Baotou Iron and Steel (Group) Co. The effects of basicity and ratio of Al2O3 to SiO2 (A/S) on the formation of silico-ferrite of calcium and aluminium (SFCA) in Baivumebo low silica sinters were studied by means of mini-sintering, XPF-500 optical mineralogical microscope and CSS-88000 electronic universal testing machine. The results show that it is beneficial to the formation of complex calcium ferrite to enhance the basicity of Baivumebo low silica sinters. The acicular SFCA-I was increased with the enhancing basicity and reached the peak at basicity 28, then the columnar or platy SFCA formed and the bonding strength decreased. Alumina is beneficial to the formation of acicular complex calcium ferrite in Baivumebo low silica sinters. But the residual unfused Al2O3 reagent came into being when A/S was 035, while complex calcium ferrite still remained to be acicular. There is a common rule about mineralogy components affected by basicity and ratio of A/S, that is, SFCA is increasing accompanied with hematite and porosity reduced, but the content of glass phase is stable.

关键词: Key words: Baivumebo iron concentrates , Baivumebo low silica sinter , SFCA , basicity , alumina-silica ratio

Formation Characteristics of Calcium Ferrite in Low Silicon Sinter

WANG Yi-ci , ZHANG Jian-liang , ZHANG Fang , LUO Guo-ping

钢铁研究学报(英文版)

Influence of sintering temperature, basicity and MgO content on the formation characteristics of calcium ferrite in low silicon sinter of Baotou Iron and Steel Company was studied by means of mini-sintering test and mineralographic microscope analysis. In addition, the suitable sintering parameters such as temperature and basicity were explored. The results found that optimum temperature for the formation of calcium ferrite is 1280 ℃, the basicity of 25-28 is helpful to the development of acicular or columnar calcium ferrite, and MgO content in the low silicon sintering raw materials should be lower than 28% because MgO can intensively inhibit the formation of calcium ferrite. And calcium ferrite in the sinter belongs to calcium ferrite with low calcium, which is different from that in ordinary sinter at home and abroad. So, it provided theoretical basis for promoting formation of calcium ferrite in low silicon sinter and improving properties of sinter.

关键词: low silicon sinter , formation characteristics , calcium ferrite , sintering temperature , basicity

0℃时YI3-C6H12N4·HI-H2O的相图及YI3·C6H12N4·HI·14H2O的合成与表征

王丽 , 吴希文 , 张晨鼎 , 张通 , 简丽 , 武朝军 , 周涛

稀土 doi:10.3969/j.issn.1004-0277.1999.02.003

采用湿渣法研究了0℃时碘化钇(YI3)-乌洛托品氢碘酸盐(C6H12N4.HI)-水(H2O)的三元体系相平衡,绘制了该体系的等温溶解度相图,相图分析结果表明,该体系中有组成为YI3.C6H12N4.HI.14H2O的配合物生成,对所得配合物进行了化学分析、X-射线粉末衍射、红外光谱、差热-热重分析,测定了其密度、晶体轴性,确定了配合物结构中的配位关系.

关键词: 相平衡 , 碘化钇 , 乌洛托品氢碘酸盐 , 配合物

Two-step magnetization in a spin-chain system on the triangular lattice: Wang-Landau simulation

Physical Review B

The Wang-Landau algorithm is used to study the thermodynamic and magnetic properties of triangular spin-chain system based on two-dimensional Ising model in order to understand the magnetic-order dynamics in Ca(3)Co(2)O(6) compound. The calculated results demonstrate that the equilibrium state of the rigid spins produces the two-step magnetization curve at low temperature even when the random-exchange term is considered. This work indicates that the four-step magnetization behavior observed experimentally must be due to the nonequilibrium magnetization.

关键词: calcium compounds;exchange interactions (electron);Ising model;magnetisation;thermodynamics;one-dimensional ca3co2o6;density-of-states;compound ca3co2o6;phase-diagram;proteins;crystal

稀土卟啉配合物电子结构和光谱的INDO/CI研究

李丽 , 郑世钧 , 孟令鹏

中国稀土学报

利用INDO/CI方法研究镧系金属卟啉配合物中稀土离子的络合高度及溶剂配位,发现稀土卟啉配合物的优化分子构型和络合高度随稀土离子半径减小而降低.对系列稀土卟啉配合物的电子光谱主要吸收带进行了指认,计算结果与实验值能较好地吻合.讨论了稀土卟啉化合物的电子结构及能级变化规律,并分析了它们的特征电子光谱.

关键词: 稀土 , 稀土卟啉配合物 , INDO/CI计算方法 , 电子结构与光谱

用N-正丁基异辛酰胺从Rh-Sn-CI体系中萃取铑

李耀威 , 古国榜

稀有金属材料与工程

研究了以SnCl2为活化试剂用N-正丁基异辛酰胺(BiOA)从Rh-Sn-CI体系中萃取Rh的性能及机制.结果表明:溶液中未添加SnCl2时,Rh几乎不能被萃取,Rh的萃取率随着溶液中CSh/CRh的值增大而增大,当溶液中CSn/CRh摩尔比达到6以上,CHCI浓度为3 mol·L-1时,用1.5 mol·L-1 TBP-正辛烷体系萃取Rh,经过3min的萃取平衡,Rh的萃取率可达到99%.BiOA和TBP对Rh有协同萃取效应,研究表明萃取反应是以酸性离子缔合机制进行.

关键词: 铑 , 溶剂萃取 , N-正丁基异辛酰胺 , 二氯化锡

N—CI-TiO2光催化剂的制备、表征及性能

于秀娟 , 杨莉莎 , 程修文

材料科学与工程学报

以钛酸四丁酯为前驱体，氯化铵为掺杂剂，采用溶胶一凝胶法制备了N、Cl共掺杂改性的TiOz光催化剂（N—Cl-Ti），借助XRD、SEM、TEM、XPS及DRS等手段对其加以表征。以苯酚为模型反应物，研究了氯化铵掺杂量及热处理温度等制备条件对光催化活性的影响。结果表明，氯化铵掺杂抑制了锐钛矿相向板钛矿相的转变和晶粒的生长，改性后的TiO。光吸收带边可延伸约至780nm。N、C1元素分别以O—Ti—N和O-Ti—C1形式存在于TiO：晶格中。当氯化铵的掺杂量为3．0mol％，热处理温度为250℃时，改性后的TiO：可见光催化活性最高，可见光（420～800nm）照射120min后，苯酚的降解率可达75．689／6。

关键词: 二氧化钛 , 氮氯共掺杂 , 可见光 , 光催化 , 苯酚

Dendritic Deposition of NH_4CI Crystals with Free Surface as Simulations of Surface Solidification of Materials

Junming LIU Zhiguo LIU Zhuangchun WU National Lab.of Solid State Microstructures , Nanjing University , Nanjing 210008 , China

材料科学技术（英文）

As a simulation of surface solidification of materials,quasi-two dimensional dendritic deposition of ammonium chloride(NH_4Cl)crystals from an aqueous solution film with free surface by vapourization was investigated by the in- situ observation technique.The depositing morphologies of NH_4Cl crystals are faceted and of growth laws differing from the three-dimensional case.Under low supersaturation,faceted dendrites formed,whereas the anisotropy in growth kinetics decreases with the increase of supersaturation.When vapourizing rate(supersaturation)is not very low, oscillations of growth rate.tip-radius and second arm spacing of the dendrites were observed.It is suggested that this dynamic phenomenon is attributed to the correlation between the convection-transfer effect induced by the surface tension gradient of solution film.and the driving force for deposition.

关键词: surface deposition , null , null , null

磁场和CI~-对铁在中性Na_2SO_4溶液中阳极极化行为的影响

吕战鹏 , 陈俊明

中国腐蚀与防护学报

用动电位扫描法研究了外加磁场及Cl~-对铁在中性0.5mol/LNa_2SO_4溶液中阳极极化行为的影响。结果表明:有、无磁场下铁在含Cl~-的Na_2SO_4溶液中的阳极极化曲线都呈现活化-钝化-过钝化特征,虽然Cl~-会阻碍钝化膜的形成过程;外加磁场使E_p和E_F正移并增大i_(max)和i_(min),使钝化区范围缩小。Cl~-与磁场同时存在时对钝化膜的破坏有协同作用。

关键词: Fe/Na_2SO_4腐蚀 , Effect of magnetic field , Effect of Cl-

不同载体负载的Cu_2(OH)_3CI催化剂对甲醇氧化羰基化的催化性能

王瑞玉 , 李忠 , 郑华艳 , 谢克昌

催化学报

采用浆液浸渍法制备了小同载体负载的Cu_2(OH)_3Cl催化剂,考察了催化剂对甲醇氧化羰基化合成碳酸二甲酯(DMC)反应的催化性能.结果表明,各载体负载的Cu_2(OH)_3Cl催化剂活性均高于传统的负载CuCl_2催化剂;以比表面积较大的活性炭(AC)为载体的催化剂活性最高.以Cu_2(OH)_3Cl/AC(w(Cu)=18.71%)为催化剂时,甲醇转化率、DMC选择性和DMC时宅收率可分别达到6.93%,67.3%和139.1mg/(g·h);其催化性能比较稳定,反应60h后其催化活性略有下降.通过CO程序升温脱附、X射线衍射、X射线光电子能谱和扫描电镜等技术对催化剂进行了表征.结果表明,在反应过程中催化剂的活性物种Cu_2(OH)_3Cl的晶粒逐渐团聚、长大,并且转化为CuCl_2和CuO;同时,新鲜催化剂中唯一的Cu~Ⅱ物种部分转化为Cu~Ⅰ物种.

关键词: 甲醇 , 氧化羰基化 , 碳酸二甲酯 , 碱式氯化铜 , 负载型催化剂 , 活性炭