China
Africa
Explore chapters and articles related to this topic
Radioactivity in Gypsum
Published in Manjit Singh, Gypsum & Gypsum Products, 2023
Blast furnace slag is used mainly as crushed aggregate in concrete as well as a finely ground mineral additive in cement. The activity concentration in slag depends on the ore type, the origin of the raw material and the metallurgic processes. The use of coal fly ash and slag in concrete is a well-recognized source of gamma exposure that is due to the presence of activity concentrations of 226Ra, 232Th and, to a lesser extent, 40K, while its effect via radon exhalation is controversial, due to the low emanation coefficient from the ash 14. Phosphogypsum used, for example, in the production of plasterboard may give rise to a concern about extremely high concentrations of 226Ra, and high radon exhalation.
Sources of Information on Sustainability Requirements
Published in J.K. Yates, Daniel Castro-Lacouture, Sustainability in Engineering Design and Construction, 2018
J.K. Yates, Daniel Castro-Lacouture
Cement is used in all types of construction, and the article by Basu and Van Zyl (2006) “Industrial Ecology Framework for Achieving Cleaner Production in the Mining and Minerals Industry” mentions numerous studies on how to improve the efficiency of cement production and how to minimize toxic emissions from the cement industry. One alternative helping to reduce the greenhouse gas emissions caused by cement production is to use coal fly ash or granulated blast furnace slag in concrete in place of some of the cement (Los Alamos National Laboratory 2002). The large kilns used to process all of the raw materials, to evaporate the water in the materials, and to calcine (heat to a high temperature to drive off water and produce a powder) the carbonate constituents (calcinations) consume 90% of the energy used to produce cement (Naik and Mariconi 2006).
Slag cement CEM III/B 42,5L-LH/SR/NA as a component of durable concrete
Published in Cezary Madryas, Andrzej Kolonko, Beata Nienartowicz, Arkadiusz Szot, Underground Infrastructure of Urban Areas 4, 2017
Z. Giergiczny, M. Batog, K. Synowiec, M. Ostrowski
Blast furnace slag is a by-product obtained by the process of melting pig iron in a blast furnace. The process is conducted at 1400–1600°C. As a result of the melting of the feed mixture a melted blast furnace slag is obtained, which after separation from the pig iron is subjected to a granulation process by rapid cooling by water. Granulated blast furnace slag is a component with latent hydraulic properties, i.e. as a result of comminution and activation, binds and hardens similarly to Portland cement (Giergiczny et al. 2015). High specific surface area and proper granulometry (Figure 1) is important for increasing the hydraulic activity of the slag and thus, obtaining slag cement with its high content in the appropriate strength class. This is illustrated by compressive strength results of slag cements containing 70% of ground granulated blast furnace with different specific surface area (Figure 2) (Ostrowski 2017). Comparatively, the compressive strength of Portland cement CEM I 42,5R is shown in Figure 2. The slag cements were obtained by mixing Portland cement CEM I 42,5R and separately ground granulated blast furnace slag with chemical composition shown in Table 1. The content of glass phase in the slag was 98.6%. Table 2 shows selected properties of granulated blast furnace slag with comparison to the requirements of the cement standard PN-EN 197-1.
Exploration of the mechanical properties, durability and application of geopolymers: a review
Published in European Journal of Environmental and Civil Engineering, 2023
Shoushuai Dai, Hongguang Wang, Hao Wu, Maohua Zhang
Slag is also called granulated blast furnace slag, which is a glassy granular material formed when molten blast furnace slag is rapidly cooled, usually by immersing in water and then ground to improve its reactivity (Yu et al., 2022). It shows primarily cementitious performance (latent hydraulic activity) but may show some pozzolanic traits (reaction with lime) as well. Slag is often used as the admixture to replace part of cement to produce blast furnace slag cement (Kumar et al., 2008; Shafigh et al., 2013). Depending on the cooling conditions, the BFS cooled in water, also known as ground granulated blast furnace slag (GGBS), is mainly used as a partial substitute for OPC after grinding due to its amorphous nature, high hardness and pozzolanic activity (W. Jiang et al., 2020; Silva et al., 2020). GGBS is one of the common raw materials for geopolymers, and the Si/Al ratio of GGBS is 1.71–3.67. GGBS is highly reactive to the synthesis of geopolymers, and it is possible to obtain a good reaction rate at a temperature as low as 0 °C (Lemougna et al., 2020b). GGBS can be used to improve the porosity, the long-term strength, resistance to sulfate and alkali silicate reactivity of concrete, and reduce the water demand, permeability and hydration heat of the concrete (Amran et al., 2020; Li & Yi, 2020).
Comprehensive utilisation of blast furnace slag
Published in Canadian Metallurgical Quarterly, 2023
Jinyu Zou, Zihan Liu, Qiang Guo
Blast furnace slag is mainly used as building materials and their products [11], such as: cement mix, gypsum, blast furnace slag micronised powder, admixture for concrete, hollow bricks, slag particle boards, etc. The development of hollow bricks with water-quenched slag and fly ash as the main raw material can not only improve the utilisation rate of blast furnace slag, but also meet the demand for developing multifunctional new wall materials in the building material’s industry at home and abroad [14]. There is a technology abroad that can use for blast furnace slag to produce glass-ceramic products, the preparation of high-grade, high-strength, high value-added glass-ceramic from blast furnace slag has a very broad market prospect in construction, decoration, and industry as wear-resistant, corrosion-resistant, high-temperature resistant, electrical insulation and other materials [15]. Adding a certain crystal seed to the blast furnace slag to increase the viscosity of the slag can be used to produce glass fibre, which has good alkali resistance compared with ordinary glass fibre, and can be more widely used in concrete engineering as a reinforcing material [15]. The United States and Japan believe that the mechanical properties of blast furnace slag are better than rolled crushed stone, and have used blast furnace slag in road construction, and have formulated relevant technical standards and construction specifications.
Destructive and Non Destructive Test Characteristics of Concrete Produced with Iron Slag Aggregate
Published in Water Science, 2021
Blast furnace slag is a byproduct and using it as aggregates in concrete will might prove an economical and environmentally friendly solution in local region. The demand for aggregates is increasing rapidly and so as the demand of concrete. Thus, it is becoming more important to find suitable alternatives for aggregates in the future.