scholarly journals Influence of B2O3and Basicity on Viscosity and Structure of Medium Titanium Bearing Blast Furnace Slag

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Lingtao Bian ◽  
Yanhong Gao

The effects of B2O3and basicity (CaO/SiO2) on the viscous behavior and structure of medium titanium bearing blast furnace slag (MTBBFS) were investigated. High temperature viscosimeter was applied to measure the viscosities of CaO-SiO2-MgO-TiO2-Al2O3-B2O3slag system and X-ray diffraction (XRD), NBO/T ratio, and structure parameterQwere employed to analyze its network structure. The results showed that the viscosity decreased and break point temperature increased with increasing basicity to 1.20. However B2O3addition gave rise to a decrease in slag viscosity and break point temperature inspite of basicity. The more B2O3content leads to the more pronounced variation, especially for the slag with larger basicity. The conventional NBO/T formula was revised to predict the structure variation of relatively complicated medium Ti bearing slag based on the work of Yanhong Gao and other researchers. The increase of B2O3content in slag made parameterQturn fromQ2toQ1, suggesting that network structure became simpler. It was also noticed that the addition of B2O3could suppress the formation of perovskite.

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Lingtao Bian ◽  
Yanhong Gao

The effect of Al2O3, CaO/SiO2, and B2O3 on the viscosity of high alumina and medium titania blast furnace slag was analyzed. An increase in CaO/SiO2 ratio from 1.14 to 1.44 resulted in higher slag viscosity and break point temperature. They also increased with increasing Al2O3 content but decreased with adding B2O3 and Al2O3 simultaneously at a fixed CaO/SiO2 ratio of 1.14, which suggested that the effect of B2O3 on viscosity and break point temperature is predominant compared to Al2O3. Apparent activation energies of CaO–SiO2–MgO–Al2O3–TiO2–B2O3 slag were found to be between 74 and 169 kJ/mol.


Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2131 ◽  
Author(s):  
G.U. Ryu ◽  
G.M. Kim ◽  
Hammad R. Khalid ◽  
H.K. Lee

Blast furnace slag, an industrial by-product, is emerging as a potential raw material to synthesize hydroxyapatite and zeolite. In this study, the effects of temperature on the hydrothermal synthesis of hydroxyapatite-zeolite from blast furnace slag were investigated. Specimens were synthesized at different temperatures (room temperature, 50, 90, 120, or 150 °C). The synthesized specimens were analyzed qualitatively and quantitatively via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), BET/BJH, and scanning electron microscopy/energy dispersive using X-ray analysis (SEM/EDX). It was found that the hydroxyapatite phase was synthesized at all the reaction temperatures, while faujasite type zeolite appeared in the specimens synthesized at 90 and 120 °C. Moreover, faujasite was replaced by hydroxysodalite in the specimens synthesized at 150 °C. Additionally, the crystals of the hydroxyapatite tended to become larger and total crystallinity increased as the reaction temperature increased.


Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3511 ◽  
Author(s):  
Joonho Seo ◽  
Solmoi Park ◽  
Hyun No Yoon ◽  
Jeong Gook Jang ◽  
Seon Hyeok Kim ◽  
...  

The solidification and stabilization of calcium carbide residue (CCR) using granulated blast furnace slag was investigated in this study. CCR binding in hydrated slag was explored by X-ray diffraction, 29Si and 27Al magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy, and thermodynamic calculations. Mercury intrusion porosimetry and and compressive strength tests assessed the microstructure and mechanical properties of the mixtures of slag and CCR. C-A-S-H gel, ettringite, hemicarbonate, and hydrotalcite were identified as the main phases in the mixture of slag and CCR. The maximum CCR uptake by slag and the highest volume of precipitated solid phases were reached when CCR loading in slag is 7.5% by mass of slag, according to the thermodynamic prediction. This feature is also experimentally observed in the microstructure, which showed an increase in the pore volume at higher CCR loading.


2016 ◽  
Vol 35 (8) ◽  
pp. 787-797
Author(s):  
Wu Zhang ◽  
Li Zhang ◽  
Yuhai Li ◽  
Xin Li

AbstractThe aim of the present work is to elucidate crystallization and growing process of rutile crystals in Ti-bearing blast furnace slag. The samples were taken from the liquid slag and quenched at once at elevated temperatures in order to analyze phase transaction of titanium and grain size of rutile crystals. Crystallization and growing kinetics of rutile crystals under elevated temperature conditions were calculated, and the crystallization process of rutile crystals under isothermal conditions was expressed by Avrami equation. The effects of experimental parameters, such as experimental temperatures, SiO2 addition, cooling rate, crystal seed addition and oxygen flow, were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), the optimal conditions for rutile crystals to grow up were obtained. Distribution and movement state of rutile crystals in the slag were analyzed.


2016 ◽  
Vol 1813 ◽  
Author(s):  
O. F. Cortés-Salmerón ◽  
M. L. García-Chávez ◽  
T. A. García-Mejía

ABSTRACTThe present work is a study on alkali activation of Mexican blast furnace slag, using sodium silicate. The aim is to produce an optimal specimen, homogeneous without carbonation, and with small fraction of crystalline phases, similar to CSH, which provide mechanical properties suitable to use in the construction industry. The samples were prepared using sodium silicate activator solutions with modulus (SiO2/Na2O) of 1.25, 1.5, and 1.75. The weight percentage of Na2O in the activator solutions was added at 4, 6 and 8% relative to the slag weight. The prepared samples were stored in sealed molds, at room temperature (20°C), during 7 days. The X-ray diffraction has revealed the presence of an amorphous phase, semi crystalline clinotobermorite phase and signals of calcium carbonate for the samples of 4 and 6 % of Na2O; in contrast with the 8% Na2O, where the latter signals almost disappeared. The specimen selected as optimal was prepared with an activator concentration of 8% of Na2O /Slag, and SiO2/Na2O of 1.25. A specimen under these optimal conditions was prepared with accelerated curing (40°C, humidity, 48 hours), and a compressive strength test was attained, with an average value of 52 MPa at 3 days.


2016 ◽  
Vol 35 (3) ◽  
pp. 309-319 ◽  
Author(s):  
Yu-Lan Zhen ◽  
Guo-Hua Zhang ◽  
Kuo-Chih Chou

AbstractThe carbothermic reduction experiments were carried out for titanium-bearing blast furnace slag in Panzhihua Iron and Steel Company in argon atmosphere at high temperatures. The effects of reduction temperature, isothermal treatment time and carbon content on the formation of TiC were studied by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD pattern results showed that MgAl2O4 phase disappeared and the main phase of the reduced sample was TiC when the reduction temperature was higher than 1,773 K. The SEM pictures showed that the reduction rate of the titanium-bearing blast furnace slag could be increased by enhancing the temperature and the C content (carbon ratio ≤1.0). Furthermore, it was also found that TiC had the tendency of concentrating around the iron. The effects of additives such as Fe and CaCl2 on the formation of TiC were also studied in the present study.


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