钢包炉（LF）CaO－SiO_2－MgO－Al_2O_3渣系的脱硫试验

钢包炉（ＬＦ）ＣａＯ－ＳｉＯ_２－ＭｇＯ－Ａｌ_２Ｏ_３渣系的脱硫试验郭上型，万真雅（华东冶金学院，马鞍山２４３００２）ＤｅｓｕｌｐｈｕｒｉｚｉｎｇＴｅｓｔｕｓｉｎｇＣａＯ－ＳｉＯ_２－ＭｇＯ－Ａｌ_２Ｏ_３ＳｌａｇｉｎＡＬａｄｌｅＦｕｒｎａｃｅ￥ＧｕｏＳ...     

CaO－Al_2O_3－SiO_2渣系氮的溶解热力学

根据炉渣结构的共存理论，推导了ＣａＯ－Ａｌ_２Ｏ_３－ＳｉＯ_２熔渣的作用浓度计算模型。模型计算得出的各组元的作用浓度值与文献报道的活度值非常一致。在此基础上，进一步采用回归分析法找出了ＣａＯ－Ａｌ_２Ｏ_３－ＳｉＯ２渣系中溶解的氮含量以及与此渣系相平衡的钢中氮含量及氮的分配比随渣中各组元作用浓度之间变化的定量关系，理论计算结果与实验值非常符合。     

添加CaO对Al2O3陶瓷混合料烧结过程活化的研究

对用高温结构陶瓷替代传统的高纯金属铜，制备高炉风嘴的可能性进行了研究，用ＳＦＭ、Ｘ射线衍射和动态模拟实验法分析了氧化铝瓷烧结过程。结果表明，在实验条件下添加２．５％ＣａＯ、３．５％ＳｉＯ_２的制品，烧结性能与力学性能最佳。制品中形成的ＣａＯ·６Ａｌ_２Ｏ_３和ＣａＯ·Ａｌ_２Ｏ_３·２ＳｉＯ_２复相促进了烧结，并使高温相接触紧密，改善了力学性能。     

凝固过程钢中氧化物成分对氧化物和硫反应的影响

为了阐明钢在凝固过程中氧化物和硫之间的反应，观察分析了连铸钢氧化物成分对它的影响，结果如下：在低Ａｌ含量钢中（Ａｌ＝０．００５％）观察到ＣａＯ－ＳｉＯ２－Ａｌ２Ｏ３和ＣａＯ－ＳｉＯ２氧化物，在高Ａｌ含量钢中（Ａｌ＝０．０３１％）看到ＣａＯ－Ａｌ２Ｏ３氧化物。ＣａＯ－ＳｉＯ２＿Ａｌ２Ｏ３和ＣａＯ－Ａｌ２Ｏ３氧化物比ＣａＯ－ＳｉＯ２氧化物具有较高的硫含量。氧化物中的Ｓ含量随钢在凝固温度下的液相率和硫容     

SiC陶瓷常压烧结研究

研究了ＳｉＣ粉末粒度、助剂Ａｌ２Ｏ３＋Ｙ２Ｏ３加入量和Ａｌ２Ｏ３与Ｙ２Ｏ３的配比等因素对ＳｉＣ陶瓷材料性能的影响。结果表明，添加Ａｌ２Ｏ３＋Ｙ２Ｏ３助剂可实现ＳｉＣ陶瓷的低温（１８５０℃）常压烧结。ＳｉＣ粉末粒度是影响可烧结性的重要因素之一，助剂加入量为２０％，Ａｌ２Ｏ３与Ｙ２Ｏ３之比为１：１时材料性能较好。     

矿热炉冶炼硅锰合金SiO2还原性研究

根据热力学原理，分析了ＳｉＯ２的还原过程及温度，碱度，Ａｌ２Ｏ３对ＳｉＯ２还原的影响，提出了提高ＳｉＯ２还原率主要措施。     

添加剂及温度对Al_2O_3－C质耐火材料中SiC晶须形成的影响

通过实验研究了加入特殊硅，活性炭等及温度对Ａｌ２Ｏ３－Ｃ质耐火材料中ＳｉＣ晶须形成的影响。结果表明，加入特殊硅及活性炭可使ＳｉＣ晶须发育得更好，并且Ａｌ２Ｏ３－Ｃ质耐火材料中ＳｉＣ晶须形成的适宜温度应在１２００℃＜Ｔ＜１４００℃之间。     

Kinetics of Reduction of Iron Oxide in CaO-SiO_2-Al_2O_3-Fe_tO Slags with Graphite Powder

ＫｉｎｅｔｉｃｓｏｆＲｅｄｕｃｔｉｏｎｏｆＩｒｏｎＯｘｉｄｅｉｎＣａＯ┐ＳｉＯ２┐Ａｌ２Ｏ３┐ＦｅｔＯＳｌａｇｓｗｉｔｈＧｒａｐｈｉｔｅＰｏｗｄｅｒＹａｎｇＸｕｅｍｉｎ①，ＨｕａｎｇＤｉａｎｂｉｎｇ②，ＫｏｎｇＬｉｎｇｔａｎ②，ＹａｎｇＴｉａｎｊｕｎ...     

中注管加入稀土与耐火材料的作用

中心注管钢流中加稀土的试验生产表明，钢中稀土可腐蚀中注管和汤道的粘土质耐火材料，并随稀土加入量和加入时间的增加而加，剧腐蚀产物中ＳｉＯ２、Ａｌ２Ｏ３逐渐减少或消失，ＲＥＡｌＯ３，ＲＥ－Ａｌ－Ｓｉ－Ｏ，ＲＥ２ＳｉＯ２等复合氧化物相依次出现，腐蚀层逐渐增厚。稀土与耐火材料反应对钢中夹杂物有一定影响，中注管部位出现大型外来ＲＥ－Ａｌ－Ｓｉ－Ｏ复合夹杂，但能被汤道耐火材料及保护渣吸收，本稀土处理工艺可使钢     

Theoretical Analysis on Tensile Strength of ZA22/Al2O3 Short Fiber Composite Added with Ce

ＴｈｅｏｒｅｔｉｃａｌＡｎａｌｙｓｉｓｏｎＴｅｎｓｉｌｅＳｔｒｅｎｇｔｈｏｆＺＡ２２／Ａｌ２Ｏ３ＳｈｏｒｔＦｉｂｅｒＣｏｍｐｏｓｉｔｅＡｄｄｅｄｗｉｔｈＣｅＹｕＳｉｒｏｎｇ（于思荣）１，ＨｅＺｈｅｎｍｉｎｇ（何镇明）２，ＲｅｎＬｕｑｕａｎ（任露泉）１...     

Evolution of oxide inclusions in W800 non- oriented electrical steel

Inclusion is one of the major factors affecting magnetic properties of non- oriented electrical steel. Steel and slag samples were sampled in the production route of W800 non- oriented electrical steel. The composition of slags and the content of TO were measured by XRF and oxygen and nitrogen analyzer. The morphology, amount and composition of oxide inclusions were analyzed by an automated scanning electron microscope ASPEX. Before adding aluminum, the oxide inclusions are mainly spherical silicon oxide and a few SiO2- MnO wrapped by SiO2. Due to the high affinity with oxygen of aluminum, the oxide inclusions changed to alumina and MgO??Al2O3 spinel after adding aluminum. Only two types of morphologies of Al2O3 can be observed by polishing and acid etching. Sphere shape, cluster and polyhedron shape of Al2O3 can be observed after electrolysis of nonaqueous solution. Therefore, electrolysis of nonaqueous solution is more effective and accurate in revealing the morphologies of oxides. The average content of MgO in inclusions increases to 8. 1 mass% during soft blowing, due to the erosion of refractories.The inclusions grows larger and are removed effectively by argon blowing. Nearly no CaO exists in oxides because of low basicity and mass ratio of CaO to Al2O3. With the addition of Al, the inclusions are SiO2, liquid SiO2- Al2O3 and Al2O3, which are in agreement with the observed results.     

低铝硅比铝土矿酸浸试验研究

对低铝硅比的铝土矿进行了探索性酸浸试验研究。试验结果表明,酸耗系数大有利于铝的溶出,直接硫酸浸出时,低的液固比有利于铝的溶出。无论是采用硫酸还是盐酸浸出,铝溶出的同时大部分铁也被溶出,浸出液用于生产硫酸铝需进行除铁处理,如考虑采用拜尔法生产冶金级氧化铝,可不除铁,直接处理即可。     

Effects of aluminum co-doping on photoluminescence properties of Ce³⁺-doped SiO₂ glasses

SiO2 glasses co-doped with Al3+ ions were prepared by a sol-gel method by holding 0.5% of Ce3+ ions constant and varying the Al3+ ions concentrations.Thermal stability,the structural,chemical and the optical properties of the samples were studied by using differential scanning calorimetric(DSC),thermo gravimetric analysis(TGA),X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),UV-vis spectroscopy and photoluminescence spectroscopy(PL).The DSC and TGA of samples depicted that the presence of dopant and co-dopant decreased the endothermic peak temperature and the yield respectively.SEM images showed that the particles were in the nano-range and spherical in shape.The XRD showed that all the samples were amorphous.The UV absorption measurements indicated that the presence of Al3+ ions significantly reduced the SiO2 absorption band,increased the absorbance intensity of SiO2 and decreased the transmittance as compared to the presence of the Ce3+ ions alone.The photoluminescence results displayed an optimum increase in luminescence intensity when the ratio of Al:Ce was 10:1 and further increase in aluminum content quenched the luminous intensity.     

CaO-SiO_2-FeO-P_2O_5渣系脱磷影响因素的研究

为了提高转炉渣中CaO的利用率,降低转炉渣的碱度,通过试验研究了CaO粒度、粒状CaO的加入比例、温度和保温时间对含磷富集相的影响。结果表明,适当增大CaO的粒度有利于2CaO·SiO2-3CaO·P2O5固溶体的形成;当渣中粒状CaO的含量较低时,增加粒状CaO的加入比例,可促进渣中大颗粒固溶体的形成并减少渣中磷的含量,但当粒状CaO的含量较高时,2CaO·SiO2-3CaO·P2O5固溶体生成量减少;适当提高温度有利于脱磷反应的进行;随反应时间的延长,2CaO·SiO2-3CaO·P2O5固溶体的粒径增大,而且固溶体中磷的含量也不断增加。     

硅在铝酸钠溶液分解过程中的行为

采用离子膜电解强化铝酸钠溶液分解,考察硅在分解过程中的行为,并用扫描电镜和电子能谱分别对自发分解产品的表面形貌及表面元素进行了表征。结果表明:二氧化硅的浓度变化在分解过程中分三个阶段,即前期迅速减少,中期基本不变,后期又缓慢减少;在分解温度不同时,二氧化硅的浓度在高温时变化较低温快。种分温度为70℃与60℃时,在分解6 h后,分解率都在50%左右。种分温度为70℃时,在前1 h分解率就达到40%左右,明显比60℃时快,说明溶液分解显著地由化学反应控制。二氧化硅使10μm以下的粒子数增加,同时二氧化硅在60℃时相比70℃更能影响粒度分布。纯铝酸钠溶液自发分解产品表面光滑,含硅铝酸钠溶液自发分解产品表面有细小粒子和不规则絮状物,表面元素分析表明絮状物为硅铝酸钠晶体之间的簇合。     

脱硫枪用莫来石—刚玉浇注料流动性的研究

以天然莫来石、电熔莫来石、刚玉粉为主要原料,研究了粒度级配、微粉种类和加入量、减水剂种类和加入量的对脱硫枪用莫来石—刚玉浇注料流动性的影响：先研究硅微粉加入量分别为2％、3％、4％、5％对浇注料流动性的影响;然后将硅微粉加入量固定为2％或3％,研究α—Al2O3微粉加入量分别为0、2％、4％、6％时对浇注料的流动性影响;最后研究三聚磷酸钠、六偏磷酸钠、SM、FDN四种减水剂对莫来石-刚玉浇注料流动性的影响,三聚磷酸钠和六偏磷酸钠的加入量分别选取0．1％、0．15％、0．2％、0．25％,SM加入量选取0．2％、0．3％、0．4％、0．5％,FDN的加入量选取0．1％、0．15％、0．2％、0．25％。试验结果表明：硅微粉对流动性的改善作用优于氧化铝微粉,但二者共用时对流动性的改善作用比单用硅微粉更好,此时最适宜的加入量为硅微粉％、氧化铝微粉2％;本试验中最适宜的减水剂是六偏磷酸钠,最佳加入量为0．15％。     

430不锈钢尖晶石夹杂物控制的热力学分析

通过热力学计算,得出了硅脱氧430不锈钢熔体Fe-Mg-Al-Si-O体系MgO.Al2O3、2MgO.SiO2、3Al2O3.2SiO2和2MgO.2Al2O3.5SiO2的平衡相图,分析了控制尖晶石夹杂物形成与转变的热力学条件。结果表明:1 873 K时,当钢中Al的质量分数在1×10-6以下,钢水中基本不形成镁铝尖晶石;随钢水中溶解铝含量的逐渐降低,由尖晶石转变为2MgO.SiO2所需的溶解氧质量分数逐渐提高。当钢水中溶解镁的质量分数在2×10-6,控制钢水中w(Al)4×10-5、w(O)8×10-6时,对于抑制不锈钢尖晶石夹杂物的形成有利。     

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Thermodynamics calculation indicates that the stable inclusion is Al2O3 for Ti-alloyed Al-killed steel. And only when Al content is below 0. 008% does Al2TiO5 emerge. Systematical samples from practical production of Ti-IF steel reveals following discoveries. Unstable Al-Ti composite oxides formed in steel possibly due to the reaction between titanium oxides in ferrotitanium and aluminum in steel. During casting process, the aluminum loss near the melt/slag interface is more sever if the content of reducible oxide such as SiO2 is higher in tundish flux. Therefore Ti enrichment happens in partial areas near the melt and thermodynamic conditions for generating Al2TiO5 or Ti3O5 could be satisfied. In addition, titanium oxides can be easily transported into steel melt by turbulent flow.     

A novel catalyst of silicon cerium complex oxides for selective catalytic reduction of NO by NH3

A series of CeO2/SiO2 and SixCe1-xO2 complex oxides supported on an activated Al2TiO5-TiO2-SiO2 complex phase (ATS) ceramics were prepared by step impregnation and co-impregnation methods, and characterized by N2-BET, XRD, SEM and NH3-TPD techniques. The effects of reaction temperature, CeO2/SiO2 loadings and Si/Ce molar ratio on the granular catalysts for NO selective catalytic reduction with ammonia (NH3-SCR) were studied. Results indicated that both CeO2/SiO2/ATS and CeO2/ATS catalysts showed the same ac...     

帘线钢中酸溶铝含量的变化及其对夹杂物的影响

 研究了采用LD－RH－LF－CC工艺流程生产帘线钢时,钢中酸溶铝含量的变化情况。研究发现,精炼过程中酸溶铝含量略有下降,但连铸过程中酸溶铝含量急剧下降。夹杂物中Al2O3含量随着酸溶铝含量的上升而逐渐增大。SiO2含量降低时夹杂物熔点提高。采用低碱度、低Al2O3含量的顶渣精炼工艺,严格控制钢中w(［Als］)在0.0005%～0.001%范围内,促进夹杂物上浮,有利于钢中氧化物夹杂的数量减少、尺寸细小和塑性化。