Study on the Modification of Blast Furnace Smelt Slag and Crystallization Behavior in the Solidification Process

2015 ◽  
Vol 1094 ◽  
pp. 352-359 ◽  
Author(s):  
Jie Li ◽  
Kai Zhao ◽  
Yu Zhu Zhang ◽  
Wei Xing Liu ◽  
Ai Min Yang
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Iron Ore ◽  
Crystallization Behavior ◽  
Vitreous Body ◽  
Solidification Process ◽  
Waste Rock ◽  
Furnace Slag ◽  
Air Hole

The direct fibrillation of blast furnace slag can solve these problems, such as having not been recycled of sensible heat, the consumption of water resources, environmental pollution and the low additional value of product, which are caused by the traditional water quenching method. The modification is the key problem of fiber forming. The thesis mainly aims at the study of viscosity of slag, the ability of crystallization and mineral phase structure after the modified process of blast furnace slag and confined the relevance of the three to optimize the appropriate texturizer and adding ratio. The results are as following: Iron ore waste rock, fly-ash and compounded texturizer can improve the high temperature viscosity of the slag respectively, while it has different effect on landing gradient of viscosity and temperature (Fly-ash occupies first place, compounded texturizer comes second and iron ore and waste rock comes the minimum). By analyzing the crystallization behavior of the slag in the solidification process, when the proportion of iron ore waste rock is more than 9%, the fly-ash is equal or greater than 8% and the compounded texturizer is more than 9%, the solidification slag will appear amorphous. The mineral composition of the slag transforms gradually from melilite to vitreous body, which will make the air hole of the vitreous body increased and aperture decreased. When the iron ore waste rock is added, the homogeneity of the air hole will deteriorate, while adding the fly-ash and compounded texturizer will strengthen the homogeneity of the air hole and make the mineral structure intensive gradually.

Crystallization behavior of blast furnace slag modified by adding iron ore tailing

2017 ◽  
Vol 24 (6) ◽  
pp. 601-607 ◽  
Author(s):  
Qian-qian Ren ◽  
Yu-zhu Zhang ◽  
Yue Long ◽  
Shao-sheng Chen ◽  
Zong-shu Zou ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Iron Ore ◽  
Crystallization Behavior ◽  
Iron Ore Tailing ◽  
Furnace Slag

scholarly journals Effect of Mineral Admixtures on the Performance of Low-Quality Recycled Aggregate Concrete

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 596
Author(s):  
Yasuhiro Dosho
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Mineral Admixtures ◽  
Structural Concrete ◽  
Aggregate Concrete ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

To improve the application of low-quality aggregates in structural concrete, this study investigated the effect of multi-purpose mineral admixtures, such as fly ash and ground granulated blast-furnace slag, on the performance of concrete. Accordingly, the primary performance of low-quality recycled aggregate concrete could be improved by varying the replacement ratio of the recycled aggregate and using appropriate mineral admixtures such as fly ash and ground granulated blast-furnace slag. The results show the potential for the use of low-quality aggregate in structural concrete.

Effects of Fly Ash and Granular Blast-Furnace Slag on Development Rate of Strength of Concrete

2014 ◽  
Vol 629-630 ◽  
pp. 371-375
Author(s):  
Ji Wei Cai ◽  
Si Jia Yan ◽  
Gong Lei Wei ◽  
Lu Wang ◽  
Jin Jin Zhou
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Development Rate ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Conventional Concrete ◽  
Enhancing Effect ◽  
Substitution Content ◽  
Furnace Slag

Fly ash (FA) and granular blast-furnace slag (GBFS) are usual mineral admixtures to conventional concrete, and their contents substituted for Portland cement definitely affect development rate of strength of concrete. C30 and C60 concrete samples with FA and/or GBFS were prepared to study the influence of substitution content of the mineral admixtures on 3 d, 7 d and 28 d strength. The results reveal that the development rate of strength in period from 3 d to 7 d gets slow with increasing content of mineral admixtures except for concrete with only GBFS less than 20%. In the case of substituting FA as the only mineral admixture for part of cement, the development rate of strength of C30 concrete in period from 7 d to 28 d keeps roughly constant even that of C60 concrete increases. When substituting mineral admixtures in the presence of GBFS for cement within experimental range, the development rate of strength in period from 7 d to 28 d gets fast with increasing substitution content. The enhancing effect of combining FA and GBFS occurs in period from 7 d to 28 d for both C30 and C60 concretes (FA+GBFS≤40%), even occurs in period from 3 d to 7 d for C60 concrete. Based on 7 d strength and the development rate, 28 d strength of concrete can be predicted accurately.

Optimization of Concrete Porous Mix Using Slag as Substitute Material for Cement and Aggregates

2017 ◽  
Vol 865 ◽  
pp. 282-288 ◽  
Author(s):  
Jul Endawati ◽  
Rochaeti ◽  
R. Utami
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Silica Fume ◽  
Blast Furnace Slag ◽  
Environmental Effect ◽  
Substitution Effect ◽  
Main Concern ◽  
Binder Material ◽  
Furnace Slag

In recent years, sustainability and environmental effect of concrete became the main concern. Substituting cement with the other cementitious material without decreasing mechanical properties of a mixture could save energy, reduce greenhouse effect due to mining, calcination and limestone refining. Therefore, some industrial by-products such as fly ash, silica fume, and Ground Iron Blast Furnace Slag (GIBFS) would be used in this study to substitute cement and aggregate. This substitution would be applied on the porous concrete mixture to minimize the environmental effect. Slag performance will be optimized by trying out variations of fly ash, silica fume, and slag as cement substitution material in mortar mixture. The result is narrowed into two types of substitution. First, reviewed from the fly ash substitution effect on binder material, highest compressive strength 16.2 MPa was obtained from mixture composition 6% fly ash, 3% silica fume and 17% grinding granular blast-furnace slag. Second, reviewed from slag types as cement substitution and silica fume substitution, highest compressive strength 15.2 MPa was obtained from mortar specimens with air-cooled blast furnace slag. It composed with binder material 56% Portland composite cement, 15% fly ash, 3% silica fume and 26% air-cooled blast furnace slag. Considering the cement substitution, the latter mixture was chosen.

Modeling of Alteration Behavior on Blended Cementitious Materials

2011 ◽  
Author(s):  
Hitoshi Owada ◽  
Tomoko Ishii ◽  
Mayumi Takazawa ◽  
Hiroyasu Kato ◽  
Hiroyuki Sakamoto ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Chemical Composition ◽  
Mineral Composition ◽  
Blast Furnace Slag ◽  
Fine Powder ◽  
Cementitious Materials ◽  
Leaching Tests ◽  
Measured Concentration ◽  
Furnace Slag

A “realistic alteration model” is needed for various cementitious materials. Hypothetical settings of mineral composition calculated based on the chemical composition of cement, such as Atkins’s model, have been used to estimate the alteration of cementitious material. However, model estimates for the concentration of certain elements such as Al and S in leachate have been different from experimental values. In a previous study, we created settings for a mineralogical alteration model by taking the initial chemical composition of cementitious materials from analysis results in experiments and applying their ratios to certain hydrated cement minerals, then added settings for secondary generated minerals in order to account for Ca leaching. This study of alteration estimates for ordinary portland cement (OPC) in groundwater showed that the change in Al and S concentrations in simulated leachate approached values for actual leachate[1]. In the present study, we develop an appropriate mineral alteration model for blended cementitious materials and conduct batch-type leaching experiments that use crushed samples of blast furnace slag cement (BFSC), silica cement (SC), and fly ash cement (FAC). The cement blends in these experiments used OPC blended with blast furnace slag of 70 wt.%, silica cement consisting of an amorphous silica fine powder of 20 wt.%, and fly ash of 30 wt.%. De-ionized water was used as the leaching solution. The solid-liquid ratios in the leaching tests were varied in order to simulate the alteration process of cement hydrates. The compositions of leachate and minerals obtained from leaching tests were compared with those obtained from models using hypothetical settings of mineral composition. We also consider an alteration model that corresponds to the diversity of these materials. As a result of applying the conventional OPC model to blended cementitious materials, the estimated Al concentration in the aqueous solution was significantly different from the measured concentration. We therefore propose an improved model that takes better account of Al behavior by using a more reliable initial mineral model for Al concentration in the solution.

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