scholarly journals Optimization of heat treatment of glass-ceramics made from blast furnace slag

2020 ◽  
Vol 39 (1) ◽  
pp. 539-544
Author(s):  
Yi-Ci Wang ◽  
Pei-Jun Liu ◽  
Guo-Ping Luo ◽  
Zhe Liu ◽  
Peng-Fei Cao

AbstractCaO–MgO–Al2O3–SiO2 glass-ceramics with diopside as the main crystalline phase were prepared by melting blast furnace slag obtained from Baotou Iron and Steel Company. The effect of heat treatment on the crystallization behavior of glass-ceramics, containing a large proportion of melted blast furnace slag, was studied by means of differential thermal analysis and scanning electron microscopy. The optimum heat-treatment regime was obtained by orthogonal experimental results for glass-ceramics in which blast furnace slag comprised 70% of the composition and 1% Cr2O3 and 4% TiO2 were used as nucleating agents. The nucleation temperature was 750°C for 2.5 h and the crystallization temperature was 930°C for 1 h. Under this regime, the performance of the glass-ceramic was better than that of other groups in the orthogonal experiment.

2019 ◽  
Vol 45 (11) ◽  
pp. 13692-13700 ◽  
Author(s):  
Wentao Zhang ◽  
Feng He ◽  
Yongli Xiao ◽  
Mongqin Xie ◽  
Junlin Xie ◽  
...  

2012 ◽  
Vol 220-223 ◽  
pp. 117-122
Author(s):  
Guo Ping Luo ◽  
Yan Ban ◽  
Yi Ci Wang ◽  
Wen Wu Yu ◽  
Qi Jiang

The mineral composition of the solidified blast furnace slag and the occurrence of special components CaF2, K2O, Na2O, RexOy and ThO2 were researched by optical microscope analysis, X-ray diffraction analysis and scanning electron microscopy and energy spectrum analysis. The results showed that the major minerals in solidified furnace slag are akermanite and gehlenite; the special component CaF2 is not hosted in the cuspidine (3CaO•2SiO2•CaF2), but in the magnesium and aluminum silicate mineral; the special components K2O,Na2O is hosted in akermanite, magnesium and aluminum silicate mineral and perovskite; the element thorium cannot form an independent mineral, but coexist with the rare earth element Ce in the perovskite. The results will lay a foundation for further study on the influence of these special components on the crystallization behavior of glass-ceramics.


2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Yici Wang ◽  
Qi Jiang ◽  
Guoping Luo ◽  
Wenwu Yu ◽  
Yan Ban

In the process of glass-ceramics prepared with Baotou steel blast furnace slag, quartz sand, and other raw materials by melting method, the mutual influence of the special components such as CaF2, REXOY, TiO2, K2O, and Na2O in the blast furnace slag on the crystallization behavior of parent glass was investigated using differential thermal analysis (DTA) and X-ray diffraction (XRD). The results show that the special components in slag can reduce the crystallization temperature and promote crystallization of glass phase, which belongs to surface crystallization of glass, and they cannot play the role of the nucleating agent; the major crystal phase composed of diopside, diopside containing aluminum and anorthite, is slightly different from the expected main crystal phase of diopside. Therefore, the nucleating agents of proper species and quantity must be added into the raw materials in order to obtain glass-ceramics. The results have important theoretical guidance meaning for realizing industrial production of Baotou steel blast furnace slag glass-ceramics preparation.


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.


2020 ◽  
Author(s):  
Zuhao Li ◽  
Feng He ◽  
Wentao Zhang ◽  
Junlin Xie

Abstract Different Al2O3/SiO2 glass-ceramics were prepared from blast furnace slag by traditional sintering method. The structure and properties of glasses or glass-ceramics were investigated by DSC, XRD, SEM, FTIR, 27Al MAS NMR. The DSC results showed that with the increase of Al2O3/SiO2, the glass transition temperature (Tg) first increased and then decreased, reached the minimum when Al2O3/SiO2 was 0.34. The volume density, bending strength and microhardness of glass-ceramics also showed the same variation rule. The FTIR and 27Al MAS NMR spectra results revealed this phenomenon. When Al2O3/SiO2 was 0.19, a large amount of Si4+ was added to the glass network to make the structure dense. With Al2O3/SiO2 increased from 0.24 to 0.34, the amount of [AlO6] in the glass increased while [AlO4] decreased, and the degree of network polymerization of the glass decreased; as Al2O3/SiO2 further increased from 0.34 to 0.39, [AlO4] increased and [AlO6] decreased in the glass, and the degree of network polymerization of the glass increased. The XRD results showed that the crystal phase of the glass-ceramics was composed of gehlenite, diopside and hyalophane. Moreover, with the increase of Al2O3/SiO2, the gehlenite content in the glass-ceramics increased, while the content of diopside and hyalophane decreased.


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