Effect of Calcium Fluoride and Magnesia on the Performance of Tundish Coverture Fluxes Made of Blast Furnace Slag

2013 ◽  
Vol 813 ◽  
pp. 96-99
Author(s):  
Zhao Hui Zhang ◽  
Bai Long Liu ◽  
Yun Ren
Keyword(s):  
Surface Tension ◽  
Blast Furnace ◽  
Melting Temperature ◽  
Calcium Fluoride ◽  
Blast Furnace Slag ◽  
Iron And Steel ◽  
Basic Performance ◽  
The Difference ◽  
The Impact ◽  
Furnace Slag

Preparation of the tundish coverture fluxes by the blast furnace slag can recycle utilization of solid wastes discharged from iron and steel industry. Calcium fluoride and magnesia can play an important role for the basic performance of tundish coverture fluxes. The impact on the melting temperature, viscosities and surface tension of the tundish coverture fluxes from the content of calcium fluoride and magnesia were studied. The results showed that: When the content of CaF2 increased from 10% to 25%, the melting temperature, the viscosity and the surface tension were decreased by 50°C, 0.3 Pa·S and 0.039 N/m respectively. The viscosity was brought down of 0.02 Pa·S, the surface tension was increased by 0.03 N/m, and the difference between the lowest and highest melting temperature was about 3°C when the content of MgO changed from 5% to 11%.

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
Keyword(s):  
Heat Treatment ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Orthogonal Experiment ◽  
Glass Ceramics ◽  
Iron And Steel ◽  
Heat Treatment Regime ◽  
Main Crystalline Phase ◽  
Optimum Heat ◽  
Furnace Slag

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.

scholarly journals Application areas of phosphogypsum in production of mineral binders and composites based on them: a review of research results

2018 ◽  
Vol 149 ◽  
pp. 01012 ◽  
Author(s):  
Leonid Dvorkin ◽  
Nataliya Lushnikova ◽  
Mohammed Sonebi
Keyword(s):  
Mechanical Properties ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Setting Time ◽  
Industrial Wastes ◽  
Cement Clinker ◽  
Complete Replacement ◽  
Slaked Lime ◽  
The Impact ◽  
Furnace Slag

The increase of the consumption of gypsum products in construction industry with a limited amount of natural gypsum deposits requires alternative sources of gypsum-containing raw materials. In some countries which have fertilizers industry plants, the problem can be solved using industrial wastes, e.g. phosphorgypsum – a byproduct of fertilizers’ production. Kept in dumps over decades, phosphorgypsum is subjected to the chemical changes due to washing out impurities with rain and other natural factors. However, there are observed deviations of harmful impurities in dumped PG depending on its age., Phosphorgypsum of any age requires chemical treatment to neutralize remains of phosphorus and sulfuric acids, fluorine compounds. According to our researches one of the most simple and effective method of neutralization the impurities is using lime-containing admixtures. The paper presents results of laboratory tests of phosphorgypsum as a component of clinker and non-clinker binders. There were investigated the impact of phosphorgypsum as admixture for clinker binders to substitute natural gypsum. Neutralized phosphorgypsum can be applied as mineralizing admixture in calcination of Portland cement clinker. Adding 2 to 2.5% of phosphorgypsum as setting time regulator resulted in a similar physical and mechanical properties compared to mix made with natural gypsum. Another important area of phosphorgypsum application is sulphate activatoion of low-clinker blast-furnace slag cement (clinker content is less than 19%). According to results, the incorporation of phosphorgypsum as sulphate activator in cement has the better effect as natural gypsum. Other development has been carried out to modify the phosphorgypsum binder properties. Complex additive consisted of polycarboxylate-based superplasticizer and slaked lime permitted an increase mechanical properties of hardened phosphorgypsum binder due to significant a reduction of water consumption. Such modified binder can be used as partial or complete replacement of gypsum binder for filling cements and finishing plasters. It can substitute gypsum in non-clinker binders like supersulphated cements. There were also developed compositions of supersulphated cements based on low-alumina blast furnace slag and phosphorgypsum. Supersulphated cements were tested in normal-weight and light-weight concrete.

Effects of blast furnace slag and steel fiber on the impact resistance of railway prestressed concrete sleepers

2019 ◽  
Vol 99 ◽  
pp. 151-164
Author(s):  
Doo-Yeol Yoo ◽  
Jin-Young Lee ◽  
Hyun-Oh Shin ◽  
Jun-Mo Yang ◽  
Young-Soo Yoon
Keyword(s):  
Blast Furnace ◽  
Prestressed Concrete ◽  
Blast Furnace Slag ◽  
Steel Fiber ◽  
Impact Resistance ◽  
The Impact ◽  
Furnace Slag

Transition of Blast Furnace Slag from Silicate Based to Aluminate Based: Density and Surface Tension

2018 ◽  
Vol 49 (3) ◽  
pp. 1322-1330 ◽  
Author(s):  
Zhiming Yan ◽  
Xuewei Lv ◽  
Zhengde Pang ◽  
Xueming Lv ◽  
Chenguang Bai
Keyword(s):  
Surface Tension ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Furnace Slag

Carbothermic Reduction of Titanium-Bearing Blast Furnace Slag

2016 ◽  
Vol 35 (3) ◽  
pp. 309-319 ◽  
Author(s):  
Yu-Lan Zhen ◽  
Guo-Hua Zhang ◽  
Kuo-Chih Chou
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Carbothermic Reduction ◽  
Treatment Time ◽  
Reduction Rate ◽  
Isothermal Treatment ◽  
Reduction Temperature ◽  
X Ray Diffraction ◽  
Iron And Steel ◽  
Furnace Slag

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.

scholarly journals Surface Tension of the Molten Blast Furnace Slag Bearing TiO2: Measurement and Evaluation

2014 ◽  
Vol 54 (10) ◽  
pp. 2154-2161 ◽  
Author(s):  
Yanhui Liu ◽  
Xuewei Lv ◽  
Chenguang Bai ◽  
Bin Yu
Keyword(s):  
Surface Tension ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Measurement And Evaluation ◽  
Furnace Slag

scholarly journals Potential of Industrial By-Products as Liming Materials and Digestate as Organic Fertilizer and Their Effect on Soil Properties and Yield of Alfalfa (Medicago sativa L.)

2021 ◽  
Vol 13 (19) ◽  
pp. 11016
Author(s):  
Vladimir Ivezić ◽  
Vladimir Zebec ◽  
Brigita Popović ◽  
Meri Engler ◽  
Tihana Teklić ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Organic Fertilizer ◽  
Acid Soils ◽  
Nutrient Status ◽  
Field Trials ◽  
Wood Ash ◽  
The Impact ◽  
Furnace Slag ◽  
By Products

Acid soils with pH values below 5.5 have a negative effect on agricultural production. For this reason, liming is applied as a measure to raise the soil pH to the optimum (pH = 6–7). The aim of our research was to evaluate and compare the effectiveness of four liming materials (wood ash from biomass powerplant, filter dust from cement factory, blast furnace slag from iron factory, and carbocalk (limestone, a by-product from a sugar factory)) in combination with and without solid digestate (a by-product from biogas plant) as organic fertilizer. Two field trials were set up to determine the effect of the studied materials to neutralize the acidity, and the impact on soil fertility and nutrient status in the soil. The results showed that all four liming materials raised the pH of the soil. Out of these four, wood ash showed to be the best while blast furnace slag was the worst. The yield of alfalfa increased with the application of all four lime materials. Application of liming materials with solid digestate increased soil organic matter and had slightly higher yields compared to liming materials without solid digestate. The highest yields were achieved with the application of wood ash, probably due to somewhat higher concentrations of potassium and phosphorus in wood ash. Further research on the financial aspects of investigated by-products application is necessary to exploit their potential as a liming material.

scholarly journals Experimental verification of shrinkage due to drying in concrete under varying humidity conditions in accordance with the Eurocode2 standard

2018 ◽  
Vol 49 ◽  
pp. 00084 ◽  
Author(s):  
Wioletta Raczkiewicz ◽  
Magdalena Bacharz
Keyword(s):  
Blast Furnace ◽  
Relative Humidity ◽  
Experimental Verification ◽  
Blast Furnace Slag ◽  
Experimental Results ◽  
Computational Results ◽  
Concrete Shrinkage ◽  
Eurocode 2 ◽  
The Impact ◽  
Furnace Slag

The concrete shrinkage depends on many factors. There are the concrete mixture, dimensions of the element and environment conditions, mainly humidity. All these factors can be imposed under laboratory conditions and controlled. In field conditions, however, a constant humidity is not possible to keep. The paper presents the impact of relative humidity changes on the values of shrinkage strains. The experimental results obtained on the specimens (with size 150x150x600 mm) were compared with the values calculated in accordance with the Eurocode 2 standard. The specimens were made with basalt aggregate without admixtures or additives. Two kinds of cement were used in preparing the specimens: Portland and blast-furnace slag cement. All specimens were treated in water for 10 days in the first days after demoulding and then subjected to testing. During the 56 days the temperature was 22 ± 2°C, while the humidity decreased proportionally from 91% to 47%. Strains were measured and the specimens were weighed to determine the mass loss. The experimental results were compared to the computational results. It should be concluded that they were not coherent in the case of ambient humidity exceeding 80% although it was accordance with the Eurocode 2 standard.

The Occurrence of Special Components in Blast Furnace Slag of Baotou Iron and Steel Company

2012 ◽  
Vol 220-223 ◽  
pp. 117-122
Author(s):  
Guo Ping Luo ◽  
Yan Ban ◽  
Yi Ci Wang ◽  
Wen Wu Yu ◽  
Qi Jiang
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Glass Ceramics ◽  
Optical Microscope ◽  
Aluminum Silicate ◽  
X Ray Diffraction ◽  
Silicate Mineral ◽  
Iron And Steel ◽  
X Ray ◽  
Furnace Slag

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.

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