Effect of Slag Basicity on Dephosphorization at Lower Basicity and Lower Temperature Based on Industrial Experiments and Ion-Molecular Coexistence Theory

2021 ◽  
Author(s):  
Han Sun ◽  
Jian Yang ◽  
Run-Hao Zhang ◽  
Wen-Kui Yang
Keyword(s):  
Slag Basicity ◽  
Coexistence Theory ◽  
Industrial Experiments ◽  
Lower Temperature ◽  
Lower Basicity

Thermodynamic Model of Calculation of Sulfur Distribution Ratio between B2O3-Containing Slag and Molten Steel

2014 ◽  
Vol 633-634 ◽  
pp. 188-191
Author(s):  
Xiang Zhu ◽  
Yang Li ◽  
Xiao Jian Fan ◽  
Hong Ming Wang ◽  
Gui Rong Li
Keyword(s):  
Molten Steel ◽  
Distribution Ratio ◽  
Thermodynamic Model ◽  
Slag Basicity ◽  
Sulfur Distribution ◽  
Coexistence Theory ◽  
Sulfur Distribution Ratio

A thermodynamic model of calculation of sulfur distribution ratio between B2O3-containing slag and molten steel has been developed on the basis of the ion and molecule coexistence theory. Based on the model, the effects of B2O3 content and slag basicity on the sulfur distribution ratio in 1873K were investigated respectively. The results indicate that the sulfur distribution ratio decreased with increasing the content of B2O3, and when the content of B2O3 exceeds 6%, the sulfur distribution ratio was lower than 2.0. Therefore, in order to ensure the desulphurization ability of slag, the content of B2O3 should be controlled at about 6%. Moreover the sulfur distribution ratio can be increased by increasing the slag basicity.

Calculation Model of Activity for Slag System of CaO-SiO2-Fe2O3

2012 ◽  
Vol 535-537 ◽  
pp. 2503-2506
Author(s):  
Xiang Zhu ◽  
Hong Ming Wang ◽  
Gui Rong Li ◽  
Yu Tao Zhao
Keyword(s):  
Significant Influence ◽  
Molten Slag ◽  
Slag System ◽  
Calculation Model ◽  
Slag Basicity ◽  
Main Structure ◽  
Fe2o3 Content ◽  
Coexistence Theory ◽  
Maximum Value ◽  
Slag Structure

Based on the coexistence theory of slag structure, the activity model of CaO-SiO2-Fe2O3 ternary slag system was established. The effects of Fe2O3 content and basicity on the activities of CaO and 2CaO•SiO2 were investigated. The structure units of Fe2O3 in the molten slag were discussed. The results indicate the slag basicity has a significant influence on the activities of CaO and 2CaO•SiO2. The activity of CaO increases with increasing slag basicity, while the activity of 2CaO•SiO2 increases with the increasing of slag basicity when the basicity is less than 1.8, which reaches the maximum value when the basicity is 1.8. In another word, when the slag basicity exceeds 1.8, the activity of 2CaO•SiO2 decreases with the increasing of slag basicity. In addition, the activities of CaO and 2CaO•SiO2 can be decreased by Fe2O3. Moreover, when the slag basicity is higher than 2.0, the activity of 2CaO•SiO2 increases slightly with the increasing of Fe2O3 content. The main structure units of Fe2O3 in molten slag are closely related to the slag basicity.

Calculation Model of Mass Action Concentrations for CaO-Al2O3-SiO2 Slag System

2012 ◽  
Vol 217-219 ◽  
pp. 39-42
Author(s):  
Hong Ming Wang ◽  
Gui Rong Li ◽  
Xiang Zhu ◽  
Yu Tao Zhao
Keyword(s):  
Slag System ◽  
Calculation Model ◽  
Slag Basicity ◽  
Mass Action ◽  
Al2o3 Content ◽  
Coexistence Theory ◽  
Slag Structure

According to the coexistence theory of melted slag structure, a calculation model of mass action concentrations for CaO-Al2O3-SiO2 slag system has been established, by which the mass action concentrations of all structure units in CaO-SiO2-Al2O3 systems are calculated. The effects of Al2O3 content and slag basicity on the mass action concentrations are investigated. The results indicate that both basicity and the content of Al2O3 have remarkable effects on mass action concentrations of CaO, 2CaO•SiO2, CaO•SiO2, CaO•Al2O3 and 2CaO•SiO2•Al2O3, etc. Furthermore, the effects of Al2O3 content on mass action concentrations are relevant with slag basicity. The basicity has more influences on mass action concentrations of CaO, CaO•SiO2, 2CaO•SiO2 and 3CaO•SiO2, whereas the basicity has little effect on mass action concentrations of other structure units in CaO-SiO2-Al2O3 system.

scholarly journals Effect of TiO2 content in slag on Ti content in molten steel

2021 ◽  
Vol 40 (1) ◽  
pp. 99-107
Author(s):  
Gang Gao ◽  
Xiaofang Shi ◽  
Zhenghai Zhu ◽  
Lizhong Chang
Keyword(s):  
Molten Steel ◽  
Laboratory Experiments ◽  
Calculation Model ◽  
Ladle Slag ◽  
Coexistence Theory ◽  
Industrial Experiments ◽  
Critical Content ◽  
Slag Structure ◽  
Dissolved Aluminum ◽  
Ti Content

Abstract A calculation model of activity for CaO–SiO2–MgO–Al2O3–TiO2 slag is established according to molecular-ion coexistence theory of slag structure to calculate the activities of Al2O3, SiO2, and TiO2 in the slag. The possibility of TiO2 reduction in the slag during refining is analyzed by thermodynamics and verified by laboratory and industrial experiments. Both theoretical analysis and laboratory experimental results show that the content of TiO2 in the ladle slag significantly influences the Ti content in molten steel. When the content of the dissolved aluminum in molten steel is 0.030–0.050%, the TiO2 content in the ladle slag should be controlled below 0.3% to prevent TiO2 reduction. The critical content of TiO2 decreases with an increasing amount of the dissolved aluminum in molten steel. In addition, silicon should be used as a deoxidizer during diffused deoxidization because aluminum as a deoxidizer would lead to the reduction of TiO2. The industrial experiments confirm the results of the laboratory experiments and thermodynamics analysis.

Calculation Model of Mass Action Concentration for CaO-B2O3-SiO2 Slag System

2013 ◽  
Vol 634-638 ◽  
pp. 3114-3117 ◽  
Author(s):  
Hong Ming Wang ◽  
Xiang Zhu ◽  
Gui Rong Li
Keyword(s):  
Slag System ◽  
Calculation Model ◽  
Slag Basicity ◽  
Mass Action ◽  
Coexistence Theory ◽  
B2o3 Content ◽  
Maximum Value ◽  
Slag Structure ◽  
Mass Action Concentration

According to the coexistence theory of melted slag structure, a calculation model of mass action concentrations for CaO-B2O3-SiO2 slag system has been established, by which the mass action concentrations of all structure units in CaO-B2O3-SiO2 systems are calculated. The results indicate that the activities of CaO and 2CaO•SiO2 can be decreased effectively by B2O3. Furthermore, when the slag basicity is higher than 2.0, the activity of 2CaO•SiO2 increases firstly and then decreases with the increasing of B2O3 content. The activity of CaO increases with the increasing of slag basicity. When the basicity is less than 2.2, the activity of 2CaO•SiO2 increases with the increase of slag basicity. Moreover, when the basicity is 2.2, the activity of 2CaO•SiO2 reaches the maximum value. In another word, the activity of 2CaO•SiO2 decreases with the increase of slag basicity on the condition that the slag basicity exceeds 2.2. B2O3 exists in the slag in the form of CaO•B2O3, 2CaO•B2O3 and 3CaO•B2O3.

Silicon Tetrachloride Synthesis from Rice Hulls: Transmission and Scanning Electron Microscope Study

1972 ◽  
Vol 30 ◽  
pp. 236-237 ◽  
Author(s):  
Richard S. Thomas ◽  
Prabir K. Basu ◽  
Francis T. Jones
Keyword(s):  
Silicon Tetrachloride ◽  
Silica Sand ◽  
Mineral Matter ◽  
Chemical Heterogeneity ◽  
Scanning Electron Microscope Study ◽  
Rice Hulls ◽  
Hull Structure ◽  
Lower Temperature ◽  
Image Position ◽  
Disposal Problem

Silicon tetrachloride, used in industry for the production of highest purity silicon and silica, is customarily manufactured from silica-sand and charcoal.SiCl4 can also be made from rice hulls, which contain up to 20 percent silica and only traces of other mineral matter. Hulls, after carbonization, actually prove superior as a starting material since they react at lower temperature. This use of rice hulls may offer a new, profitable solution for a rice mill byproduct disposal problem.In studies of the reaction kinetics with carbonized hulls, conversion of SiO2 to SiCl4 was found to proceed within a few minutes to a constant, limited yield which depended reproducibly on the ambient temperature of the reactor. See Fig. 1. This suggested that physical or chemical heterogeneity of the silica in the hull structure might be involved.

Surface energy of cellulosic materials: The effect of particle morphology, particle size, and hydroxyl number

TAPPI Journal ◽  
2015 ◽  
Vol 14 (9) ◽  
pp. 565-576 ◽  
Author(s):  
YUCHENG PENG ◽  
DOUGLAS J. GARDNER
Keyword(s):  
Particle Size ◽  
Surface Energy ◽  
Particle Morphology ◽  
Nanofibrillated Cellulose ◽  
Particle Sizes ◽  
Hydroxyl Number ◽  
Small Individual ◽  
Dispersion Component ◽  
Commercial Applications ◽  
Lower Temperature

Understanding the surface properties of cellulose materials is important for proper commercial applications. The effect of particle size, particle morphology, and hydroxyl number on the surface energy of three microcrystalline cellulose (MCC) preparations and one nanofibrillated cellulose (NFC) preparation were investigated using inverse gas chromatography at column temperatures ranging from 30ºC to 60ºC. The mean particle sizes for the three MCC samples and the NFC sample were 120.1, 62.3, 13.9, and 9.3 μm. The corresponding dispersion components of surface energy at 30°C were 55.7 ± 0.1, 59.7 ± 1.3, 71.7 ± 1.0, and 57.4 ± 0.3 mJ/m2. MCC samples are agglomerates of small individual cellulose particles. The different particle sizes and morphologies of the three MCC samples resulted in various hydroxyl numbers, which in turn affected their dispersion component of surface energy. Cellulose samples exhibiting a higher hydroxyl number have a higher dispersion component of surface energy. The dispersion component of surface energy of all the cellulose samples decreased linearly with increasing temperature. MCC samples with larger agglomerates had a lower temperature coefficient of dispersion component of surface energy.

Formation of Nanocrystalline Silicon in Tin-Doped Amorphous Silicon Films

2020 ◽  
Vol 65 (3) ◽  
pp. 236
Author(s):  
R. M. Rudenko ◽  
O. O. Voitsihovska ◽  
V. V. Voitovych ◽  
M. M. Kras’ko ◽  
A. G. Kolosyuk ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Crystalline Silicon ◽  
Solid Phase ◽  
Nanocrystalline Silicon ◽  
Recrystallization Temperature ◽  
Nanocrystalline Phase ◽  
Silicon Phase ◽  
Silicon Nanocrystallites ◽  
Lower Temperature ◽  
Two Stages

The process of crystalline silicon phase formation in tin-doped amorphous silicon (a-SiSn) films has been studied. The inclusions of metallic tin are shown to play a key role in the crystallization of researched a-SiSn specimens with Sn contents of 1–10 at% at temperatures of 300–500 ∘C. The crystallization process can conditionally be divided into two stages. At the first stage, the formation of metallic tin inclusions occurs in the bulk of as-precipitated films owing to the diffusion of tin atoms in the amorphous silicon matrix. At the second stage, the formation of the nanocrystalline phase of silicon occurs as a result of the motion of silicon atoms from the amorphous phase to the crystalline one through the formed metallic tin inclusions. The presence of the latter ensures the formation of silicon crystallites at a much lower temperature than the solid-phase recrystallization temperature (about 750 ∘C). A possibility for a relation to exist between the sizes of growing silicon nanocrystallites and metallic tin inclusions favoring the formation of nanocrystallites has been analyzed.

Quality indicators of the spontaneous fermentation starters of cereals flour during the lower-temperature conservation process

2018 ◽  
Vol 6 (11) ◽  
pp. 116-122
Author(s):  
Larysa Mikhonik ◽  
◽  
Inna Getman ◽  
Natalia Bela ◽  
Halyna Bogdan ◽  
...  
Keyword(s):  
Quality Indicators ◽  
Spontaneous Fermentation ◽  
Lower Temperature ◽  
Fermentation Starters

The Binding and Viscometric Studies of Ni+2, Co+2 and Mn+2 Ions with Protein by Spectrometric and pH Metric Techniques

2019 ◽  
Vol 9 (2) ◽  
pp. 151-162
Author(s):  
Shveta Acharya ◽  
Arun Kumar Sharma
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Protein Molecule ◽  
Vital Role ◽  
Sufficient Evidence ◽  
Structural Requirement ◽  
Nickel Ions ◽  
Cobalt Ions ◽  
Lower Temperature ◽  
Specific Oxidation

Background: The metal ions play a vital role in a large number of widely differing biological processes. Some of these processes are quite specific in their metal ion requirements. In that only certain metal ions, in specific oxidation states, can full fill the necessary catalytic or structural requirement, while other processes are much less specific. Objective: In this paper we report the binding of Mn (II), Ni (II) and Co (II) with albumin are reported employing spectrophotometric and pH metric method. In order to distinguish between ionic and colloidal linking, the binding of metal by using pH metric and viscometric methods and the result are discussed in terms of electrovalent and coordinate bonding. Methods: The binding of Ni+2, Co+2 and Mn+2 ions have been studied with egg protein at different pH values and temperatures by the spectrometric technique. Results: The binding data were found to be pH and temperature dependent. The intrinsic association constants (k) and the number of binding sites (n) were calculated from Scatchard plots and found to be at the maximum at lower pH and at lower temperatures. Therefore, a lower temperature and lower pH offered more sites in the protein molecule for interaction with these metal ions. Statistical effects seem to be more significant at lower Ni+2, Co+2 and Mn+2 ions concentrations, while at higher concentrations electrostatic effects and heterogeneity of sites are more significant. Conclusion: The pH metric as well as viscometric data provided sufficient evidence about the linking of cobalt, nickel and manganese ions with the nitrogen groups of albumin. From the nature and height of curves in the three cases it may be concluded that nickel ions bound strongly while the cobalt ions bound weakly.

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