Na2O对连铸保护渣熔化性能的影响

实验研究了Na2O对连铸保护渣熔化性能的影响规律，测定了实验渣系的熔化温度、熔化速度和结晶温度．结果表明，在实验渣基本成分条件下，Na2O的质量分数为10％时，保护渣的熔化特性能够满足高速连铸要求．     

CaO-BaO-Al2O3-SiO2-MgO-CaF2精炼渣系熔化温度研究

利用正交试验的方法进行CaO-BaO-Al2O3-SiO2-MgO-CaF2精炼渣系熔化温度的研究,结果表明,BaO的质量分数在0～15％范围内精炼渣系的熔化温度随BaO含量升高而降低;CaO/Al2O3含量比值由1增加到2,精炼渣系熔化温度逐渐升高,而CaO/Al2O3含量比值由2增加到4,精炼渣系熔化温度又开始下降;SiO2的质量分数由8％～20％,精炼渣系熔化温度随SiO2含量升高而升高.     

BN对超低碳钢连铸保护渣性能的影响

采用C BN作为骨架粒子,研究开发了一种新型的超低碳钢保护渣.其性能可以满足超低碳钢连铸的需要.C BN作为骨架粒子可以使保护渣的粘度减小、熔化温度降低、熔化速度降低、结晶温度降低.     

中薄板坯连铸保护渣研究

系统地研究了中薄板坯连铸保护渣的化学成分与理化性能，熔化温度、熔化速度和粘度的关系，探讨了保护渣中的Al2O3、F^-、碳质量分数及碱度的大小对保护渣理化性能的影响，得到了优化的保护渣成分，为开发满足现场工艺要求的中薄板坯连铸保护渣提供理论依据和指导。     

碱度和Al2O3对中碳钢宽厚板连铸结晶器保护渣粘度和熔化温度的影响

分别研究了碱度为0.92,1.0,1.14,碱度为1.0时Al2O3的质量分数为4.3％,5.0％,6.1％时中碳钢宽厚板连铸结晶器保护渣粘度和熔化温度的变化.试验结果表明,随着保护渣的碱度由0.92升高到1.14,保护渣的粘度逐渐降低.碱度的不断增加保护渣的半球点温度迅速上升.本渣系中随着Al2O3的质量分数由4.3％增加到6.1％,保护渣粘度逐渐降低,保护渣粘度的降低保证了保护渣的润滑特性.Al2O3质量分数的增加对保护渣半球点温度的影响不是很剧烈,对保护渣的熔化温度起到降低的作用.     

超低碳钢连铸保护渣的特点

为了使保护渣良好地完成5个方面的作用，最重要的就是使控制结晶器保护渣粉形成“三层结构”．为此，在渣粉中配加适当碳粉以控制熔化速度．如果渣子熔化速度控制得合适，在结晶器液面上会形成“液渣-烧结-粉渣”的合理结构，再加上钢液面波动小，钢渣界面波动较小，渣中的碳消耗殆尽，不会造成铸坯增碳．     

保护渣成分对结晶矿相的影响

熔融保护渣在MoSi2高温电阻炉内以2℃／min降温速率冷却至室温，制成薄片，采用岩相显微镜分析保护渣的结晶矿相．结果表明：在本实验条件下，结晶矿相主要有枪晶石，硅灰石，黄长石，个别渣样有霞石，萤石，橄榄石；增大保护渣碱度，能促进保护渣结晶；随着渣中CaF2，Na2O，K2O和Li2O质量分数的增大，保护渣结晶化率增大；随着渣中Al2O3，MgO，BaO和MnO质量分数的增大，保护渣结晶化率减小．     

F,MgO对包钢高炉渣性能影响的实验研究

根据目前包钢高炉渣的成分采用二次回归方法配制合成渣,通过对合成渣的粘度、熔化性温度及熔化区间的测定,研究F和MgO对包钢高炉渣性能的影响程度,寻求适宜的高炉渣成分.实验结果表明,当炉渣中w(F)≤1%时,CaF2具有降低炉渣开始熔化温度,增加炉渣熔化区间,降低炉渣热焓,降低炉渣粘度和炉渣熔化性温度的作用.随着炉渣中MgO的质量分数的增加,炉渣的热稳定性提高,炉渣粘度降低,当w(MgO)=11.652%时,熔化性温度达到最高值.     

Li2O对CaO-SiO2-Fe2O3-MnO2-MgO-P2O5系钢包渣变性处理的实验研究

为控制钢包中钢水回磷和进行炉外脱磷,以Li2O作变性剂替代CaO-SiO2-Fe2O3-MnO2-MgO-P2O5系中部分CaO,研究了Li2O对渣系的熔化性能、粘度和脱磷能力的影响。结果表明,在控制渣系组成为：w(CaO Li2O)w(SiO2)=2.5,w(Li2O)=15%,w(Fe2O3 MnO2)=7%,w(P2O5) ≤3％的条件下,该渣系熔点低、粘度适中且脱磷能力强,能够对钢水进行钢包中的脱磷处理和回磷控制。     

电渣熔铸中渣池集中高温区对电极熔化的影响研究

电渣熔铸是一种利用大电流通过渣池区域而产生的高温将自耗电极逐渐熔化的方法,其中渣池的温度分布特点直接决定了电极的熔化速度、提纯度以及铸锭的组织结构等,是熔铸系统中的关键区域.本文采用“反向熔铸”实验和“真假双电极熔铸”实验对渣池温度场分布进行了研究,并对实验模型进行了数值模拟.实验和模拟计算均证实了电极端部与金属熔池之间的渣池区域存在着一个集中的高温区,该高温区的存在对自耗电极的熔化起了极大的促进作用.     

超声波法制备球形Li3PO4粉末

为了制备锂离子电池正极材料球形LiFePO4,以曲拉通-100(Tx-100)作表面活性剂,用超声波法制备了LiFePO4的前驱体材料μm级球形Li3PO4粉末,并用X射线衍射进行了表征.研究了各种因素对Li3PO4颗粒形态的影响,得到了超声波法制备球形Li3PO4粉末的适宜条件:反应温度为35℃,Li+的浓度为0.6 mol/L,Tx-100的质量百分数为10%,超声波作用时间为5 min.     

Transition of Y<Subscript>2</Subscript>BaCuO<Subscript>5</Subscript> phase in powder melting processed YBa<Subscript>2</Subscript>Cu<Subscript>3</Subscript>O<Subscript>7−x</Subscript> superconductors

The morphology and the formation of Y2BaCuO5 phase in powder melting processed YBa2Cu3O7-x superconductors were investigated. The experimental results show the heat treatment can not change the shape of Y2BaCuO5 particles in powder melting processed samples. The formation of round Y2BaCuO5 phase is due to relative content of each constitution of precursor powders in powder melting process. For powder melting process, the excessive liquid phase is eliminated, which restrains the preferred growth of Y2BaCuO5 ...     

Research on mold flux for hypo-peritectic steel at high casting speed

Mold fluxes having adaptable properties were developed in the laboratory to solve quality defects, such as depressions and longitudinal cracks when casting hypo-peritectic steel at high casting speed. Firstly, the effect of components on the high basicity mold flux properties was first studied using the orthogonal method. In the scope of the studied content, Li2O has the largest effect on the melting temperature, and the least effect on the viscosity; CaF2 has the largest effect on the viscosity, and the least effect on the melting temperature; Na2O and CaO/SiO2 have no obvious influence on the melting temperature and viscosity. Secondly, two powders (Z1 and Z6) have reasonable viscosity-temperature curves, higher solidification temperatures, and porous structure after solidification, but the crystal property of Z6 is worse than that of Z1, and thus Z1 is more suitable for continuous casting hypo-peritectic steel at high casting speed. Thirdly, a higher basicity of powder, a less free enthalpy of crystal compound, and a lower baffle energy are good for a higher tendentiousness of crystal.     

Li_2O-P_2O_5-V_2O_5系统玻璃“晶化前期”电导研究及ESR对钒离子价态分析

本文确定了Li_2O-P_2O_5-V_2O_5系统玻璃的形成范围。采用交流电桥法测定了几组样品的电导率,lg(σT)～1/T曲线表明是由两个直线段构成,电导率在转变温以后的“晶化前期”异常增加,分析认为由于玻璃结构有序化程度增加所致。利用ESR实验对玻璃中钒离子价态进行了分析,表明该系统玻璃仅以V~(4+)和V~(5+)钒离子状态存在。随Li_2O含量增加,V~(5+)离子浓度增加,试样电子电导下降。文中从结构角度对玻璃性能进行了讨论。     

Preparation and Performance of Hollow Spherical Li_4Ti_5O_(12) Doped by Mg~(2+)

The microstructure and performance of Li_4Ti_5O_(12) doped by Mg prepared by hydrothermal method and solid phase method were investigated. Lithium dihydrate, magnesium acetate and tetrabutyl titanate were used as the main raw materials. This study reveals that Mg~(2+) has influences on the spherical structure, crystal development of Li_4Ti_5O_(12) and the electrochemical performances. The hollow spherical structure is composed of nano-sheet structure and the nano-sheet structure can be affected by the Mg~(2+) content. For Li4-xMgxTi5 O12, the sheet structure can be refined with the increment of Mg~(2+) content when x value is 0-0.1 and coarsen with the increment of Mg~(2+) content when x value is 0.1-0.2. The hollow spherical Li_4Ti_5O_(12) powders prepared by hydrothermal method have better performance. The optimal Mgdoped amount of hydrothermal method is 0.1. At 0.1 C, the first discharge capacity of Li_(3.9)Mg_(0.1)Ti_5O_(12) prepared through hydrothermal method at 0.1 C and 10 cycles is 182 and 178 m A h g~(-1), respectively.     

Al2O3对中钛高炉渣冶金性能影响的实验研究

为实现高铝矿与钒钛磁铁矿的合理搭配,研究了含铝中钛高炉渣中Al2O3含量变化对炉渣黏度及熔化性温度的影响．研究结果表明,在炉渣二元碱度1.15,W（TiO2）=12％,W（MgO）=9％的条件下,实验炉渣在W（Al2O3）=14％时具有良好的流动性和最低的熔化性温度（1348℃）．为高炉实际生产提供一定的理论依据．     

STUDY ON THE MIXED COORDINATED Ge IN GLASS OF Li_2O-ZnO-GeO_2 SYSTEM

In this paper,the authors used the MixedCoordination EXAFS Analysis Method recentlypublished and IR to study the mixed coordination ofGe in glasses of Li_2O-ZnO-GeO_2 system,a new kindof syperionic conductor.The results show that whenthe content of ZnO is fixed,the ratio of [GeO_6]units is increased with the addition of Li_2O untilthe content of Li_2O is about 15%,and thendecreased.The relationship between the ratio of[GeO_6]and the content of Li_2O is consistent withthose between n,d of glass and Li_2O content,Therefore the germanium abnormalty can be explainedas the change of coordination number.     

熔融法制备纳米SiO_2颗粒

介绍了以Na2O-B2O3-SiO2玻璃为原料,采用熔融法制备钠硼硅玻璃,并通过对钠硼硅玻璃的组分,熔制温度的讨论,以及对热处理,酸浸析等后处理过程工艺参数进行调节,得到制得纳米SiO2颗粒的最优化条件。采用差示扫描量热法对热处理前的钠硼硅玻璃进行测试,用X射线衍射分析对不同温度热处理的钠硼硅进行测试,用场发射扫描电子显微镜对酸浸析后二氧化硅颗粒形貌进行表征,并对最佳的工艺条件进行了讨论。制得的SiO2颗粒粒径范围为60～100 nm,并具有比表面积大、分散性好、成本低等优点。     

稀土Eu对发光玻璃白光发射的调控

用高温熔融法制备了Eu2O3单掺和Ce/Tb/Eu三元共掺杂的CaO-B2O3-SiO2(CBS)发光玻璃材料,并使用荧光分光光度计和CIE色度坐标对其结构以及发光特性进行了研究.光谱分析结果表明:在394nm激发下,Eu2O3单掺杂的CBS发光玻璃的发射光谱中出现了Eu3+的特征发射峰.这些发射峰主要起源于Eu3+中的4f电子的f-f跃迁;在374nm激发下,三元共掺杂发光玻璃的发射光谱中同时观测到了起源于Ce3+、Tb3+和Eu3+的蓝色、绿色和红色的三基色发射,这些发射可进一步混合成为白光发射.此外,Ce/Tb/Eu三元共掺杂发光玻璃的发光颜色,随着Eu2O3含量的增加从蓝光逐渐过渡到白光,这显示出了发光颜色的可调节性,极大地扩展了其在白光发光领域中的应用.