Thermodynamic Study on Interfacial Reaction between Blast Furnace Slag and Silicon Carbide

2016 ◽  
Vol 723 ◽  
pp. 622-627
Author(s):  
Hirohide Okuno ◽  
Naotaka Fukami ◽  
Nobuya Shinozaki

Silicon carbide(SiC) is used as a raw material contained in the refractory that is in contact with molten iron or slag during steel-making processes. In present work, the interfacial reactions between the SiC ceramic substrate and the blast furnace slag were investigated and the thermodynamic study on the reaction products was carried out. The results showed that the Ti component contained in the slag became TiC, and gathered at the whole interface between the SiC substrate and the slag after experiments.

Author(s):  
Jean Noël Yankwa Djobo ◽  
Dietmar Stephan

AbstractThis work aimed to evaluate the role of the addition of blast furnace slag for the formation of reaction products and the strength development of volcanic ash-based phosphate geopolymer. Volcanic ash was replaced by 4 and 6 wt% of ground granulated blast furnace slag to accelerate the reaction kinetics. Then, the influence of boric acid for controlling the setting and kinetics reactions was also evaluated. The results demonstrated that the competition between the dissolution of boric acid and volcanic ash-slag particles is the main process controlling the setting and kinetics reaction. The addition of slag has significantly accelerated the initial and final setting times, whereas the addition of boric acid was beneficial for delaying the setting times. Consequently, it also enhanced the flowability of the paste. The compressive strength increased significantly with the addition of slag, and the optimum replaced rate was 4 wt% which resulted in 28 d strength of 27 MPa. Beyond that percentage, the strength was reduced because of the flash setting of the binder which does not allow a subsequent dissolution of the particles and their precipitation. The binders formed with the addition of slag and/or boric acid are beneficial for the improvement of the water stability of the volcanic ash-based phosphate geopolymer.


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.


2014 ◽  
Vol 937 ◽  
pp. 462-464 ◽  
Author(s):  
Wei You ◽  
Yan Mei Jiang ◽  
Qian Lin ◽  
Xiao Xia Yu ◽  
Peng Fei Li ◽  
...  

The blast furnace slag is an industrial solid waste in the production process, this paper deals with the blast furnace slag as products -- artificial jade cup handicraft lost wax casting process of high additional value of main raw material, firstly analyses the production process of chemical composition and artificial jade common blast furnace slag and natural jade, then the detailed design of the lost wax casting process of artificial jade cup, including manufacturing, shell mould manufacturing, dewaxing, baking, imitation jade material melting and casting. The lost wax casting method for producing artificial jade crafts complex products, the added value of products, so as to achieve a high added value utilization of blast furnace slag.


2019 ◽  
Vol 38 (2019) ◽  
pp. 726-732 ◽  
Author(s):  
Yi-ci Wang ◽  
Wen-bin Xin ◽  
Xiao-geng Huo ◽  
Guo-ping Luo ◽  
Fang Zhang

AbstractIn this study, the blast furnace slag of the Baotou Steel and Iron Company was used as the main raw material to prepare glass ceramics with diopside as the main crystal phase. The composition of the parent glass was designed by thermodynamic calculations with FactSage software. Small amounts of the nucleation agent Cr2O3 were then added to the parent glass to induce crystallization. Differential thermal analysis was used to determine the nucleation and crystallization temperatures of the glasses, and scanning electron microscopy and X-ray diffraction were adopted to determine the microstructures and phase compositions of the glasses after heat treatment, respectively. The results showed that glass ceramics of the diopside phase can be prepared with up to 73 wt% blast furnace slag when 1.44–1.91 wt% Cr2O3 is added, and the ceramics have uniform compact grains and a high bending strength of about 84.6–101.7 MPa. In addition, the mechanical properties are better than those of natural marble and granite. These results provide basic information and a scientific basis for industrial production of diopside glass ceramics using molten blast furnace slag as the main raw material.


2019 ◽  
Vol 138 (6) ◽  
pp. 4571-4583
Author(s):  
Anna A. Kuśnierz ◽  
Magdalena Szumera ◽  
Magda Kosmal ◽  
Paweł Pichniarczyk

Abstract A glass set with a high content of blast-furnace slag and a reduced amount of traditional raw materials requires optimization of the raw material composition and adjustment of its specificity to the temperature regime of melting, homogenizing and clarifying the glass mass. The introduction of an increased amount of blast-furnace slag allows to reduce the cost of raw materials: soda, limestone and high-class sand, reduce energy costs, whose consumption significantly decreases and reduces CO2 emissions in line with EU requirements. The tests of thermal analysis of a glass set with different contents of Calumite are aimed at learning the mechanism of its operation by determining the changes caused by its different presence in the course of subsequent reactions between the components of the glass set. Analysis of the influence of the addition of different Calumite slag contents treated as a substitute for the raw material on the melting process of glassware sets was analyzed. The tests were carried out using differential thermal analysis (DTA) and thermogravimetry (TG) based on the model glass [mass%]: 73.0% SiO2, 1.0% Al2O3, 10.0% CaO, 2.0% MgO and 14.0% Na2O. The effect of combining Calumite with sulphate and multi-component fining agent—mixtures of As2O3, Sb2O3, NaNO3 in proportions of 1:1:1 for chemical reaction and phase transformation, was investigated.


2013 ◽  
Vol 818 ◽  
pp. 68-71 ◽  
Author(s):  
Dominik Gazdič

Within the work the questions of the slag-sulphate binder preparation were solved. It was specifically a monitoring of obtained technological properties and course of the hydration process in dependence on dosing ratio of particular binder components. A finely ground Stramberk blast furnace slag was the basic raw material to which Polish natural anhydrite was added together with Portland cement CEM I 42,5 N as alkaline exciter.


2015 ◽  
Vol 30 (3) ◽  
pp. 374-380 ◽  
Author(s):  
Jie Li ◽  
Weixing Liu ◽  
Yuzhu Zhang ◽  
Aimin Yang ◽  
Kai Zhao

Author(s):  
V. Lepa ◽  
◽  
O. Prohnymak ◽  

The problem of the accumulation of waste from the metallurgical industry in Ukraine, in particular, blast furnace slag, has an economic and environmental component. Therefore, the main problems, first of all, include the absence of a criterion for the greening of the industrial sector among the priorities of Ukraine's economic policy. The article examines the situation in the slag industry of Ukraine, summarizes the existing experience of using metallurgical slags as technogenic raw materials. The problems of introducing a circular economy in the territory of intensive development of the metallurgical industry are considered primarily in the context of creating a flexible infrastructure for processing metallurgical waste, because the problem of waste is at the center of attention of the entire circular economy. But such an infrastructure cannot be created without overcoming the technological, economic, and institutional problems of utilizing blast-furnace slags in Ukraine, which hinder the creation of a slag processing industry on the principles of a circular economy. Based on the assessment of macroeconomic and environmental effects from the introduction of elements of a circular economy in the domestic metallurgical industry, the resource value of blast furnace slags as a technogenic raw material for the construction industry, in particular the cement industry, as well as road construction and other areas of use, has been proved. The ways of solving the economic and institutional problems of slag processing at the macro-, meso- and microeconomic levels are given, proposals are made to improve the legal framework for the development of the circular economy, the participation of the state, local authorities and business in the creation of a domestic industry for the processing of blast-furnace slag.


Author(s):  
Urtnasan Erdenebold ◽  
Jei-Pil Wang

Copper smelting slag is a solution of molten oxides created during the copper smelting and refining process, and about 1.5 million tons of copper slag is generated annually in Korea. Oxides in copper smelting slag include ferrous (FeO), ferric oxide (Fe­2O3), silica (SiO­2 from flux), alumina (AI2O3), calcia (CaO) and magnesia (MgO). Main oxides in copper slag, which iron oxide and silica, exist in the form of fayalite (2FeO·SiO2). Since the copper smelting slag contains high content of iron, and copper and zinc. Common applications of copper smelting slag are the value added products such as abrasive tools, roofing granules, road-base construction, railroad ballast, fine aggregate in concrete, etc., as well as the some studies have attempted to recover metal values from copper slag. This research was intended to recovery Fe-Cu alloy, raw material of zinc and produce reformed slag like a blast furnace slag for blast furnace slag cement from copper slag. As a results, it was confirmed that reduction smelting by carbon at temperatures above 1400°С is possible to recover pig iron containing copper from copper smelting slag, and CaO additives in the reduction smelting assist to reduce iron oxide in the fayalite and change the chemical and mineralogical composition of the slag. Copper oxide in the slag can be easily reduced and dissolved in the molten pig iron, and zinc oxide is also reduced to a volatile zinc, which is removed from the furnace as the fumes, by carbon during reduction process. When CaO addition is above 5wt.%, acid slag has been completely transformed to calcium silicate slag and observed like blast furnace slag.


2021 ◽  
Vol 1203 (3) ◽  
pp. 032096
Author(s):  
Wandercleiton Cardoso ◽  
Danielle Barros ◽  
Raphael Baptista ◽  
Renzo di Felice

Abstract Portland cement additions have been used for many years with the main objective of reducing the amount of clinker. Among the additions, blast furnace slag, resulting from the production of pig iron, that is, reusing this by-product, reduces the emission of carbon dioxide as well as decreases the exploitation of natural limestone and clay reserves, which are raw materials for Portland clinker. In order to reduce these emissions and increase the availability of raw materials, research has been directed to study clinker-free binders, as is the case with activated alkali cements and supersulfated cements. In this way, alkali-activated cements can only involve the reuse of industry by-products and do not require the calcination of the raw material, thus reducing the emission of polluting gases into the atmosphere. Supersulfated cement are composed of up to 90% blast furnace slag, in addition to 10 to 20% calcium sulfate. One of the most important characteristics of blast furnace slag is the ratio of the content of CaO and SiO2, also known as the simplified basicity index (B2). This paper proposes the mathematical modeling of an artificial neural network to predict the final chemical composition of the blast furnace slag to be produced based on the operational parameters of the blast furnace aiming its use in the production of special cements such as alkali-activated cements and supersulfated cements. The high values of (R) associated with low values (RMSE) show the good statistical performance of ANN demonstrating that the mathematical model is efficient to carry out the forecast of the production of blast furnace slag.


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