Comparison of Effects of B2O3 and CaF2 on Metallurgical Properties of High Basicity CaO-Based Flux

2011 ◽  
Vol 311-313 ◽  
pp. 966-969
Author(s):  
Hong Ming Wang ◽  
Li Li Yang ◽  
Hua Zhu ◽  
Yong Qi Yan
Keyword(s):  
Melting Temperature ◽  
Inflection Point ◽  
Equal Mass ◽  
Temperature Curve ◽  
Point Temperature ◽  
Metallurgical Properties ◽  
High Basicity ◽  
Mass Ratios ◽  
Fluxing Agent ◽  
Better Than

B2O3 is employed as fluxing agent of high basicity CaO-based flux to substitute for CaF2. The effects of B2O3 and CaF2 on the metallurgy properties of CaO-based flux were investigated. The results indicate that the fluxing action of B2O3 is better than that of CaF2. For the high basicity CaO-based flux, when CaF2 is substituted with B2O3, the melting temperature can be decreased remarkably. Especially, when the mass ratios of CaO/SiO2 are in range of 5.25~8.0, the flux melting temperature is lower than 1300 °C. The inflection point temperature of flux viscosity-temperature curve is lowered remarkably when B2O3 is employed to substitute for CaF2. Meanwhile, the desulfurization capacity of flux can be improved markedly when CaF2 is substituted with equal mass of B2O3.

The Melting Temperature of CaO-(2CaO•SiO2)-B2O3-SiO2-(Al2O3) Slag System

2012 ◽  
Vol 217-219 ◽  
pp. 35-38 ◽  
Author(s):  
Hong Ming Wang ◽  
Pei Si Li ◽  
Gui Rong Li ◽  
Mian Zhang ◽  
Zhao Zhao ◽  
...  
Keyword(s):  
Melting Temperature ◽  
Slag System ◽  
Refining Process ◽  
Alumina Content ◽  
Melting Temperatures ◽  
High Basicity ◽  
Secondary Refining ◽  
Mass Ratios ◽  
Fluxing Agent

The melting temperatures of CaO-(2CaO•SiO2)-B2O3-SiO2-(Al2O3) slag system were investigated. The results indicate that B2O3 has significant fluxing effect on this slag system. When the content of B2O3 is about 10% in these slag system, the mass ratios of w(CaO)/w(SiO2) and (CaO)/w(Al2O3) can be controlled in the scope of 1.5-8.0, the melting temperature of slag is still lower than 1340°C, which is suitable for steelmaking and secondary refining process. As a conclusion, when 10% B2O3 is employed as fluxing agent, a kind of CaO-based slag system with ultra-high basicity, ultra-low alumina content as well as low melting temperature can be obtained.

scholarly journals Melting features and viscosity of SiO2-CaO-MgO-Al2O3-FeO nickel slag in laterite metallurgy

2013 ◽  
Vol 49 (1) ◽  
pp. 9-12 ◽  
Author(s):  
C. Pan ◽  
X. Lv ◽  
C. Bai ◽  
X. Liu ◽  
D. Li
Keyword(s):  
Inflection Point ◽  
Chemical Properties ◽  
Slag System ◽  
Softening Temperature ◽  
Temperature Curve ◽  
Recovery Ratio ◽  
Point Temperature ◽  
Distribution Of Elements ◽  
Ratio Energy ◽  
Temperature Melting

Physic-chemical properties of slag at high temperature were very important for the production of ferronickel alloy by pyrometallurgical process. It determines the operation efficiency, metal recovery ratio, energy consumption and the distribution of elements (like S and P) between the slag and metal. In the present work, the effect of slag basicity on melting features and viscosity of the slag was investigated. The basicity of the SiO2-CaO-MgO-Al2O3-FeO quinary slag system varied from 0.76 to 0.99. The results showed that: 1) all the slag samples began to soften at the same temperature; 2) the softening temperature, melting temperature and flowing temperature decreased with the increase of basicity from 0.76 to 0.92, after that, the temperatures would increase sharply. 3) the inflection point temperature of viscosity-temperature curve became larger and larger with the increase of basicity within 0.76 ~ 0.99.

A New Method for Calculating the Inflection Point Temperature of Heavy-Oil Rheology Transforming from Non-Newton Fluid into the Newton Fluid

2021 ◽  
pp. 1-16
Author(s):  
Dong Liu ◽  
Yonghui Liu ◽  
Nanjun Lai ◽  
Youjun Ji ◽  
TingHui Hu
Keyword(s):  
Newtonian Fluid ◽  
Heavy Oil ◽  
Inflection Point ◽  
High Viscosity ◽  
Current Approach ◽  
Temperature Data ◽  
New Method ◽  
Good Correspondence ◽  
Point Temperature ◽  
Shengli Oilfield

Abstract The inflection point temperature of rheology (IPTR) of heavy oil transforming from a non-Newtonian fluid into a Newtonian fluid is a key parameter in the steam huff- and-puff process. It is particularly relevant in terms of optimizing injection parameters, calculating the heating radius, and determining well spaces. However, the current approach exhibits obvious shortcomings, such as the randomness of the selected tangent line and inadaptability for extra-heavy oil with high viscosity. Therefore, this paper presents a novel method for calculating IPTR using viscosity–temperature data. The approach is based on the Arrhenius equation and quantitatively evaluates the IPTR according to the inflection point of the apparent activation energy. The IPTR values of four heavy-oil samples obtained from the Bohai Oilfield in China were quantitatively predicted according to viscosity–temperature data using the proposed method. The method's accuracy was verified by a series of rheological investigations on samples obtained from two heavy-oil wells. Additionally, the new method was used to predict IPTR according to the published viscosity–temperature data of 10 heavy-oil samples from the Shengli Oilfield. Again, a good correspondence was found, and mean absolute and relative errors of 3°C and 4.6%, respectively, were reported. Therefore, the proposed model was confirmed to improve the prediction accuracy of the existing method, and provided a new method for calculating the IPTR of heavy-oil.

scholarly journals Statistical Properties of Solar-Type Close Binaries

2004 ◽  
Vol 191 ◽  
pp. 20-27
Author(s):  
J.-L. Halbwachs ◽  
M. Mayor ◽  
S. Udry ◽  
F. Arenou
Keyword(s):  
Binary Stars ◽  
Equal Mass ◽  
Open Clusters ◽  
Statistical Properties ◽  
Spectroscopic Binaries ◽  
Close Binary ◽  
Close Binaries ◽  
Multiple Systems ◽  
Short Period ◽  
Mass Ratios

AbstractTwo Coravel radial velocity surveys dedicated to F7-K field dwarfs and to open clusters are merged in order to investigate the statistical properties of binaries with periods up to 10 years. Thanks to the accurate trigonometric parallaxes provided by Hipparcos, an unbiased sample of spectroscopic binaries (SB) is selected. After correction for the uncertainties of the measurements, the following results are obtained: 1. The distribution of mass ratios exhibits a peak for equal-mass binaries (twins), which is higher for short-period binaries than for long-period binaries. 2. Apart from the twins, the distribution of mass ratios exhibits a broad peak from 0.2 to 0.6. 3. The orbital eccentricities of twins are slightly smaller than those of other binaries. 4. An excess of SB is observed with periods shorter than about 50 days in comparison with the Duquennoy and Mayor log-normal distribution of periods. These features suggest that close binary stars are generated by two different processes. A possible difference could come from the accretion onto the binary, for instance from a common envelope or from a circumbinary disk. Alternatively, twins could come from dynamic evolution of multiple systems. It is not clear whether the formation models are already sufficiently elaborated to reproduce our statistics.

Effect of B2O3 Substituted for CaF2 as Fluxing Agent on Melting Temperature of Converter Slag

2012 ◽  
Vol 538-541 ◽  
pp. 2203-2206 ◽  
Author(s):  
Ting Wang Zhang ◽  
Hong Ming Wang ◽  
Gui Rong Li ◽  
Xun Yin Zhang
Keyword(s):  
Melting Temperature ◽  
Converter Slag ◽  
Sio2 Content ◽  
Fluxing Agent

B2O3 is used as fluxing agent of converter slag to substitute for CaF2 so as to reduce fluorine pollution and decrease the melting temperature. Hemisphere method is used to measure the melting temperature of samples. Effect of ω(CaO)/ω(SiO2), content of Fe2O3 and content of B2O3(CaF2) on the melting temperature of CaO-SiO2-F2O3-B2O3(CaF2) system have been studied. Results indicate that the melting temperature of samples are decreased when B2O3 substitute for CaF2 equally with equal ω(CaO)/ω(SiO2) and content of Fe2O3 [ω(CaO)/ω(SiO2)=1.5~5.0, Fe2O3=0~30%], the melting temperature of samples are decreased remarkably with the increase of content of B2O3 [ω(CaO)/ω(SiO2)= 2.5].

scholarly journals Ladder-shape melting temperature isothermal amplification of nucleic acids

BioTechniques ◽  
2021 ◽  
Author(s):  
Deguo Wang ◽  
Yongzhen Wang ◽  
Meng Zhang ◽  
Yongqing Zhang ◽  
Juntao Sun ◽  
...  
Keyword(s):  
Melting Temperature ◽  
Internal Transcribed Spacer ◽  
Prevention And Control ◽  
Lamp Assay ◽  
Temperature Curve ◽  
Isothermal Amplification ◽  
Proof Of Concept ◽  
Different Types ◽  
Novel Method ◽  
And Control

A novel method, termed ladder-shape melting temperature isothermal amplification (LMTIA), was developed in this study. As a proof of concept, one pair of primers or two pairs of nested primers and a thermostable DNA polymerase were employed to amplify the internal transcribed spacer of Oryza sativa with the ladder-shape melting temperature curve. Our results demonstrated that the LMTIA assay with nested primers was 50-fold more sensitive than the LAMP assay with the same level of specificity. The LMTIA method has the potential to be used for the prevention and control of emerging epidemics caused by different types of pathogens.

Effects of SiO2 and Al2O3 Contents of Converter Slag on Metallurgical Properties

2012 ◽  
Vol 581-582 ◽  
pp. 373-377
Author(s):  
Long Li
Keyword(s):  
Raw Materials ◽  
Converter Slag ◽  
Downward Trend ◽  
Research Results ◽  
Ladle Slag ◽  
Metallurgical Properties ◽  
High Basicity ◽  
Melting Characteristics ◽  
Melting Properties ◽  
Smelting Slag

Using ladle slag, ferrovanadium smelting slag as well as metallurgical auxiliary materials as raw materials, the converter slag with SiO2 content of 11.3% to 2.8%, Al2O3 content of 3.3% to 19.4% were prepared. The melting characteristics of slag were measured, at 1600 °C both dephosphorization and desulfurization tests of slag were conducted in atmosphere furnace. The research results show that the melting properties of slag are improved with the reduce of SiO2 content and the increase of Al2O3 content in slag, in favor of making high basicity slag in the early stages of BOF steelmaking. However, both dephosphorization and desulfurization of slag exhibit downward trend. The mechanism of SiO2 and Al2O3 contents of converter slag impact on metallurgical properties would be further discussed.

Effects of B2O3 and CaF2 on Melting Properties of CaO-Based Slags

2012 ◽  
Vol 217-219 ◽  
pp. 511-514
Author(s):  
Hong Ming Wang ◽  
De Fu ◽  
Gui Rong Li ◽  
Xiang Zhu ◽  
Zhao Zhao ◽  
...  
Keyword(s):  
Melting Temperature ◽  
Steelmaking Process ◽  
Melting Temperatures ◽  
Steelmaking Slags ◽  
Melting Properties ◽  
Fluxing Agent

B2O3 is employed as fluxing agent of CaO-SiO2-Fe2O3 steelmaking slags to substitute for CaF2. The influences of B2O3 and CaF2 on the melting properties of this system slags were investigated and compared. The results indicate that the fluxing effect of B2O3 is more remarkable than that of CaF2. Therefore, B2O3 promotes the dissolution of CaO, SiO2 and 2CaO•SiO2, etc, then the slagging speed can be improved greatly. The melting temperatures of slags increase with the increasing of basicity, especially, when CaF2 is used as fluxing agent as well as the basicity is up to 5.0, the melting temperature is increased higher than 1420°C. These characteristics of boron-containing slgas are more suitable for steelmaking process than those of fluoride-containing slags.

The Fundamental Mechanical Characteristics Evaluation for Bolted Pipe Flange Connections With RTJ Gaskets Under Internal Pressure

2019 ◽  
Author(s):  
Kenshiro Nakade ◽  
Koji Sato ◽  
Toshiyuki Sawa
Keyword(s):  
Plastic Deformation ◽  
Contact Stress ◽  
Inflection Point ◽  
Mechanical Characteristics ◽  
Design Method ◽  
Leak Rate ◽  
Bolt Preload ◽  
Higher Temperature ◽  
Sealing Mechanism ◽  
Better Than

Abstract Bolted pipe flange connections with metallic flat gaskets or ring type joint (RTJ) gaskets are used under higher pressure and higher temperature. However, a sealing mechanism is not known and a design method is not established how to determine bolt preload for preventing leakage from the connection with metallic gaskets. In addition, the characteristics of the connection are not known when oval and octagonal gaskets are used. In previous paper, when the contact stress of metallic flat gasket reaches the stress at plastic deformation inflection point, the leak rate is decreased rapidly. However, the leak rate could be measured up to 1.0 × 10−5 Pa · m3/s level. The objectives of the paper are to measure the leak rate of the metallic flat gasket of which the contact stress is over the stress at plastic deformation inflection point, and to measure the leak rate of 1.0 × 10−9∼10 Pa · m3/s level in the flat metallic gasket in the platen tests and the connection with RTJ gaskets. In addition, the characteristics of the connection are examined when oval and octagonal gaskets are used. As a result, it is found that the leak rate for the metallic flat gasket can be measured around 1.0 × 10−9∼10 Pa · m3/s in the platen tests when the contact stress of aluminum gasket reaches the stress at plastic deformation inflection point and more while the leak rate of SUS 304 flat gasket is around 1.0 × 10−7∼8 Pa · m3/s even if the contact stress is over 1.3 times of the stress at plastic deformation inflection point. In addition, the sealing characteristics of the connection with oval gasket are shown to be better than that with octagonal gasket. From a laser microscope observation, it is found that the contact area of oval gasket in the connection is smaller than that of octagonal gasket in the connection.

scholarly journals The σ-bump in elliptical galaxies – a signature of major mergers?

2016 ◽  
Vol 11 (S321) ◽  
pp. 122-122
Author(s):  
Anna T. P. Schauer ◽  
Felix Schulze ◽  
Rhea-Silvia Remus ◽  
Andreas Burkert
Keyword(s):  
Power Law ◽  
Globular Clusters ◽  
Velocity Dispersion ◽  
Elliptical Galaxies ◽  
Equal Mass ◽  
Disk Galaxies ◽  
Two Dimensional ◽  
Mass Ratios ◽  
Observable Feature ◽  
First Time

AbstractThe stellar radial velocity dispersion profiles of elliptical galaxies can be well described by a power-law σ(r)∝r−β. We analyze a set of elliptical galaxies formed by major mergers of isolated disk galaxies with mass ratios of 1:1 and 3:1 for several orbital configurations (Johansson et al. 2009). The galaxies in our sample show a deviation from the power-law at 1 − 3Reff, which we term the σ-bump (Schauer et al. 2014). This feature is most prominent in remnants of 1:1 mergers and weakens for remnants of mergers with smaller mass ratios, indicating that the σ-bump is a signature of an equal mass merger. The σ-bump does not vanish with time but stays constant once it has formed, in contrast to shells. It can be seen under all projections, making it an observable feature in the outskirts of elliptical galaxies. We indeed identify three possible σ-bump candidates in the sample of 12 SLUGGS-survey ellipticals studied by Pota et al. (2013), who use globular clusters as tracers for the outer stellar halos (see Schauer et al. 2014, for more details). For further comparisons, we here provide for the first time a two dimensional map of the velocity dispersion of one simulated σ-bump galaxy, to identify the σ-bump in observations of kinematic maps out to several Reff. The σ-bump appears as a global ring-like feature if seen face-on and as an extended box-like feature in its edge-on projection.

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