X射线荧光光谱法测定矾土中硅、铁、钾、钙、钛、锰、铝、镁、磷等氧化物含量

建立了X射线荧光光谱法测定矾土中硅、铁、钾、钙、钛、锰、铝、镁、磷等氧化物的方法。以四硼酸锂做熔剂、溴化锂做脱模剂制备玻璃熔片 ,以标准物质和高纯试剂制备标准片做校正曲线 ,并对吸收增强效应和光谱重叠做出校正。通过测定标准样品进行比较 ,本法没有显著性差异。回收率为 86.7%～ 10 6.2 %。     

Critical evaluation and optimization of the thermodynamic properties and phase diagrams of the MnO-TiO2, MgO-TiO2, FeO-TiO2, Ti2O3-TiO2, Na2O-TiO2, and K2O-TiO2 systems

All available thermodynamic and phase diagram data have been critically assessed for all phases in the MnO-TiO₂, MgO-TiO₂, FeO-TiO₂, Ti₂O₃-TiO₂, Na₂O-TiO₂, and K₂O-TiO₂ systems at 1 bar pressure from 298 K to above the liquidus temperatures. All reliable thermodynamic and phase diagram data have been simultaneously optimized to obtain, for each system, one set of model equations for the Gibbs energy of the liquid slag as a function of composition and temperature and equations for the Gibbs energies of all compounds as functions of temperature. The modified quasichemical model was used for the molten slag phases.     

Nitrogen solubility in CaO-SiO2, CaO-MgO-SiO2, and BaO-MgO-SiO2 melts

Nitrogen solubility in molten CaO-SiO₂, CaO-MgO-SiO₂, and BaO-MgO-SiO₂ silicate systems was measured as functions of nitrogen and oxygen partial pressures and composition at 1823 K. Experimental findings indicate that nitrogen exists as a free nitride ion or is associated with silicate networks, depending principally on the slag composition. A special analytical technique was developed to separately determine the two species. Its dissolution mechanism, which is similar to that for hydrogen, was proposed, being supported by the detection of a Si-N bond by infrared spectroscopy. Neither the content of free nor incorporated nitrogen was demonstrated to have a very good correlation with the CaO or SiO₂ activity in the melts, probably because the activity coefficient of nitrogen is affected by the slag composition. Formerly Graduate Student, Department of Metallurgy, The University of Tokyo.     

Phosphate capacity of CaO-AI2O3 slags containing CaF2, BaO,Li2O,or Na2O

Phosphorus partition ratios between CaO-Al₂O₃ and CaO-Al₂O₃-CaF₂ fluxes and Fe-C_sat-P alloys have been measured as a function of slag composition at 1500 °C. The effects of additions of BaO, Li₂O, and Na₂O to the CaO-Al₂O₃-CaF₂ system on the phosphorus partition ratios at 1400 °C and 1300 °C have been measured. From the partition ratio, and assuming that the oxygen potential is controlled by C-CO equilibrium, the phosphate capacities of the fluxes were calculated. Also, the activities of Li₂O and Na₂O were measured as a function of slag composition at 1300 °C by equilibrating the flux and the metal with Pb-Li or Pb-Na alloy and CO in a graphite crucible. The results indicate that phosphorus partition ratios with carbon-saturated iron and the phosphate capacities for additions of more basic oxides decrease in the following order: Na₂Oτ;Li₂Oτ;BaO. The activities of Li₂O and Na₂O in calcium aluminate fluxes have large negative deviations from ideal behavior; the activity coefficients at infinite dilution are on the order of 0.05 and 10^-5, respectively. Formerly Graduate Student, Department of Metallurgical Engineering and Materials Science, Carnegie Mellon University     

ICP-AES法测定铁矿石中SiO2,CaO,MgO,Al2O3,MnO,P,TiO2等成分

采用碳酸钠和硼酸混合熔剂,用碱融法处理试样,并通过实验条件的优化,克服了引入大量基体对测定的干扰,实现了ICP-AES法对铁矿石、烧结矿中SiO2,CaO,MgO,Al2O3,MnO,P,TiO2等成分的同时测定.本方法试剂用量少,分析速度快,线性范围宽,分析结果准确、可靠.     

Potentiostatic polarization measurements on solid platinum-molten PbO-GeO2, PbO-SiO2, and Na2 O-SiO2 interfaces

Potentiostatic polarization measurements were carried out to investigate the mechanism of the charge transfer process on solid platinum-molten PbO-GeO₂, PbO-SiO₂, and Na₂O-SiO₂ interfaces over a temperature range of 900° to 1135°C in an atmosphere of air and argon-oxygen gas mixtures.     

ICP-AES法测定铁矿石中SiO_2,CaO,MgO,Al_2O_3,MnO和TiO_2

采用电感耦合等离子体发射光谱法对铁矿石中SiO2 ,CaO ,MgO ,Al2 O3,MnO ,TiO2 的分析进行了试验研究。试液中10mg/mLFe存在时 ,基体效应明显 ,采用基体匹配办法消除铁的干扰。Ca ,Mg ,Al,Si,Ti,Mn ,Ni,Cr ,Cu ,Co ,Zn ,V ,Ba之间没有干扰 ;稀土元素对SiO2 的测定有干扰。Al,Ca ,Mg ,Mn ,Si,Ti的检出限分别为 0.5 ,0.12 5 ,0.0 5 ,0.0 5 ,0.2 5 ,0.0 0 2 5 μg/mL ,回收     

Thermodynamic optimization of the systems PbO-SiO2, PbO-ZnO, ZnO-SiO2 and PbO-ZnO-SiO2

Liquidus-phase equilibrium data of the present authors for the PbO-ZnO-SiO₂ system, combined with phase equilibrium and thermodynamic data from the literature, were optimized to obtain a self-consistent set of parameters of thermodynamic models for all phases. The modified quasichemical model was used for the liquid slag phase. From these model parameters, the optimized ternary-phase diagram was back-calculated.