Thermodynamic Research of Boron Oxide Reducing with Carbothermic Method

2012 ◽  
Vol 236-237 ◽  
pp. 755-758
Author(s):  
Ding Guo Zhao ◽  
Shu Huan Wang ◽  
Xiao Jie Cui ◽  
He Jun Zhang
Keyword(s):  
Ternary System ◽  
Partial Pressure ◽  
Carbon Content ◽  
Phase Diagrams ◽  
Boron Oxide ◽  
Normal Pressure ◽  
Activity Model ◽  
Thermodynamic Condition ◽  
Coexistence Theory ◽  
B2o3 Content

Based on the phase diagrams analysis, the activity model of Fe-C-B ternary system was established with the ion and molecule coexistence theory. The activities of Fe, C, B, Fe3C, FeB, FeB2 and B4C in melt were calculated by analyzing the model. We have researched the thermodynamic condition of boron oxide reducing with carbothermic method and analyzed the effects of CO partial pressure, B2O3 content and slag type for the lowest smelting temperature. In normal pressure, the carbon content is high in melt, so it needs 2000°C for decarbonizing and chrome remaining. When CO partial pressure is 0.1 kPa and CaO content is less 60%, the lowest temperature of smelting ferro boron could be below 1600°C.

Phase Diagram of the System LaCl3-CaCl2-NaCl

1987 ◽  
Vol 42 (12) ◽  
pp. 1421-1424 ◽  
Author(s):  
K. Igarashi ◽  
H. Ohtani ◽  
J. Mochinaga
Keyword(s):  
Phase Diagram ◽  
Ternary System ◽  
Phase Diagrams ◽  
Binary Systems ◽  
Eutectic Point ◽  
Peritectic Point

The phase diagram of ternary system LaCl3-CaCl2-NaCl has been constructed from the phase diagrams of the three binary systems and of thirteen quasi-binary systems determined by DTA. For the binaries LaCl3-CaCl2 and CaCl2-NaCl eutectic points were observed at 651 °C , 35.1 mol% LaCl3 and at 508 °C , 49.9 mol% NaCl, respectively. For LaCl3-NaCl, a peritectic point besides the eutectic point at 545 °C , 36.1 mol% LaCl3 was found at 690 °C , 57.5 mol%, which is attributable to the formation of the peritectic compound 3 LaCl3 · NaCl. The phase diagram of the ternary system has a ternary eutetic point and a ternary peritectic point due to 3 LaCl3-NaCl, the form er at 462 °C and 12.1 - 3 9 .7 - 4 8 .2 mol% (LaCl3-CaCl2-NaCl) and the latter at 612 °C and 26.9 - 55.1 - 18.0 mol%.

Phase Diagrams of Binary Systems Mg(NO3)2-KNO3, Mg(NO3)2-LiNO3 and ternary system Mg(NO3)2-LiNO3-NaNO3

2020 ◽  
Vol 65 (7) ◽  
pp. 3420-3427
Author(s):  
Yuan Zhong ◽  
Junsheng Yuan ◽  
Min Wang ◽  
Jinli Li
Keyword(s):  
Ternary System ◽  
Phase Diagrams ◽  
Binary Systems

scholarly journals Phase Equilibria and Phase Diagrams for the Ternary Aqueous System Containing Lithium, Sodium, and Pentaborate Ions at 298.15 and 323.15 K and 101.325 kPa

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Panpan Li ◽  
Kaiyu Zhao ◽  
Shangqing Chen ◽  
Jiayin Hu ◽  
Yafei Guo ◽  
...  
Keyword(s):  
Refractive Index ◽  
Ternary System ◽  
Phase Equilibria ◽  
Phase Diagrams ◽  
Invariant Point ◽  
Aqueous System ◽  
Eutectic Type ◽  
Two Temperatures ◽  
Sodium Pentaborate Pentahydrate ◽  
Experimental Values

Phase equilibria and phase diagrams for the ternary aqueous system containing lithium, sodium, and pentaborate ions at 298.15 and 323.15 K and 101.325 kPa were investigated by the methods of isothermal dissolution equilibrium. From the experimental data, the phase diagrams and the diagrams of physicochemical properties versus composition of lithium pentaborate in the equilibrium systems were plotted, respectively. The phase diagrams of the ternary system LiB5O8 + NaB5O8 + H2O at two temperatures contain one invariant point, two univariant curves, and two crystallization regions corresponding to sodium pentaborate pentahydrate (NaB5O8·5H2O) and lithium pentaborate pentahydrate (LiB5O8·5H2O). Due to the different dissolution behaviors of pentaborate salts in the aqueous systems, the component of LiB5O8 has a relatively strong effect on the solubility of NaB5O8. It was found that this system belongs to a simple eutectic type at two temperatures, and neither double salts nor solid solutions were formed. The densities and refractive indices in the ternary system at 298.15 and 323.15 K are as similar as changing regularly with the increase of LiB5O8 concentration. On the basis of empirical equations of the density and refractive index in electrolytes, the calculated values of density and refractive index agreed well with the experimental values at two temperatures.

Mechanochemical behavior of magnesium–boron oxide–melamine ternary system in the synthesis of h-BN nanopowder

2016 ◽  
Vol 42 (5) ◽  
pp. 6450-6456 ◽  
Author(s):  
Omid Torabi ◽  
Mohammad Hossein Golabgir ◽  
Hamid Tajizadegan ◽  
Amin Jamshidi
Keyword(s):  
Ternary System ◽  
Boron Oxide

A Thermodynamic Model for Evaluation of Mass Action Concentrations of La2O3-Al2O3-CaF2-CaO-MgO Slags for Electroslag Remelting Based on the Ion and Molecule Coexistence Theory

2013 ◽  
Vol 32 (6) ◽  
pp. 541-550 ◽  
Author(s):  
Chengchuan Wu ◽  
Guoguang Cheng ◽  
Jun Tian
Keyword(s):  
Phase Diagrams ◽  
Thermodynamic Model ◽  
Mass Fraction ◽  
Electroslag Remelting ◽  
Mass Action ◽  
Coexistence Theory ◽  
Maximum Value ◽  
Mass Action Concentration ◽  
Increasing Temperature ◽  
Good Agreement

AbstractAccording to the ion and molecule coexistence theory (IMCT) for molten slags and corresponding phase diagrams, a thermodynamic model for the evaluation of mass action concentrations (designated by Ni for structure unit i) for La2O3-Al2O3, La2O3-Al2O3-CaF2, La2O3-Al2O3-CaF2-CaO, La2O3-Al2O3-CaF2-MgO and La2O3-Al2O3-CaF2-CaO-MgO slag systems for electroslag remelting (ESR) has been formulated. The influencing factors for the mass action concentration of La2O3, such as mass fraction of Al2O3, CaF2, CaO and MgO and temperature, were investigated. The results show that when the mole fraction of La2O3 is at 0.495, the mass action concentration of La2O3 · Al2O3 achieves its maximum value 0.946 in the La2O3-Al2O3 binary slag. In a composition area of La2O3: 10wt% ∼ 45wt%, Al2O3: 0wt% ∼ 50wt% and CaF2: 20wt% ∼ 70wt% of the La2O3-Al2O3-CaF2 ternary slag at 1873 K, the results show that the calculated values of NLa2O3 are in good agreement with the reported measured values of aLa2O3. The iso-curves of NLa2O3 is also drawn from the calculated results, which reveals that the mass action concentration of La2O3 decreases with the increasing of the Al2O3 and CaF2 content, and Al2O3 is stronger than CaF2 in decreasing the mass action concentration of La2O3. However, in La2O3-Al2O3-CaF2-CaO, La2O3-Al2O3-CaF2-MgO and La2O3-Al2O3-CaF2-CaO-MgO slag systems, the mass action concentration of La2O3 increases with the increasing of the MgO and CaO content, and CaO is stronger than MgO in increasing the mass action concentration of La2O3. In addition, the mass action concentration of La2O3 increases with the increasing temperature at the composition of 30wt%La2O3, 10wt%Al2O3, 40wt%CaF2, 10wt%MgO and 10wt%CaO.

Calculation Model of Mass Action Concentrations for CaO-MnO-FeO-SiO2-MgO-Al2O3 Slags Based on the Ion and Molecule Coexistence Theory

2012 ◽  
Vol 476-478 ◽  
pp. 134-138
Author(s):  
Xiao Hong Yang ◽  
Xiao Chun Ma ◽  
Cheng Chuan Wu ◽  
Guo Guang Cheng
Keyword(s):  
Phase Diagrams ◽  
Thermodynamic Model ◽  
Slag System ◽  
Calculation Model ◽  
Mass Action ◽  
Structural Units ◽  
Coexistence Theory ◽  
Slag Structure ◽  
Calculation Results ◽  
Good Agreement

According to the ion and molecule coexistence theory (IMCT) of slag structure and corresponding phase diagrams, a thermodynamic model for calculating mass action concentrations of structural units or ion couples of CaO-MnO-FeO-SiO2-MgO-Al2O3 slags was established. Equilibrium mass action concentrations of each structure unit were gained. And the calculation results of NFeO and NMnO were compared with measured aFeO and aMnO. The comparison shows that the calculated values of NFeO and NMnO are in good agreement with the reported measured values of aFeO and aMnO, so this calculating model could fairly describe the characteristics of the slag system.

A Thermodynamic Model for Evaluation of Mass Action Concentrations of Ce2O3-contained Slag Systems Based on the Ion and Molecule Coexistence Theory

2013 ◽  
Vol 32 (3) ◽  
pp. 207-214 ◽  
Author(s):  
Chengchuan Wu ◽  
Guoguang Cheng ◽  
Hu Long ◽  
Xiaohong Yang
Keyword(s):  
Phase Diagrams ◽  
Thermodynamic Model ◽  
Mass Fraction ◽  
Aluminum Content ◽  
Mass Action ◽  
Coexistence Theory ◽  
Cerium Content ◽  
Maximum Value ◽  
Mass Action Concentration ◽  
Good Agreement

AbstractAccording to the ion and molecule coexistence theory (IMCT) for molten slags and corresponding phase diagrams, a thermodynamic model for the evaluation of mass action concentrations (designated by Ni for structure unit i) for Ce2O3-Al2O3, CaO-Al2O3-Ce2O3 and CaO-Al2O3-SiO2-Ce2O3 slag systems has been formulated. The results show that when the mole fraction of Ce2O3 is at 0.49 in the binary slag, the mass action concentration of Ce2O3·Al2O3 achieves its maximum value 0.90. In a composition area of CaO/Al2O3 (mass fraction ratio) from 0.7 to 1.5 and Ce2O3 content (mass fraction) from 0 to 45% of the ternary slag at 1773 K, the results show that trends of calculated NAl2O3 are in good agreement with reported measured trends of aAl2O3. The iso-curves of NCe2O3 and NCaO are also drawn from the calculated results. A thermodynamic model of the equilibrium between 55.83%CaO-23%Al2O3-11.17%SiO2-10%Ce2O3 quaternary slag and molten steel containing aluminum has been further discussed. Results indicate that certain content of Ce would be dissolved in steel, which increases with the increasing of temperature and aluminum content, and when the aluminum content is 0.02%, the corresponding cerium content is in the range of 1.87 to 13.30 ppm at 1873 K. In summary, using Ce2O3 to replace Al2O3 can effectively reduce NAl2O3, certain content of Ce can dissolved in steel.

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