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History of the Industrial Briquetting in Ferrous Metallurgy
Published in Aitber Bizhanov, Briquetting in Metallurgy, 2022
Another noteworthy attempt to carry out briquetting without firing was undertaken in 1936 at the Krivoy Rog briquette factory. Briquettes were made from ore fines of rich hematite ore. To the ore fines 5–10% of crushed iron shavings and 0.5–1.0% NaCl in the form of a solution were added, which accelerated the process of formation of iron oxide hydrates. The briquettes’ strengthening was achieved as a result of corrosion and hydration of iron shavings. The hardening of briquettes for some ores was completed within a few hours after their production. For most ores, the curing period was 20–40 hours. Briquettes did not need drying or firing. In literature, this way of briquetting is known as the method of Yarkho, after him [15]. The same method of briquetting was used at the briquette factory built in 1933 in Nizhny Tagil. However, this generally successful way did not become a landmark in cold agglomeration. The obvious disadvantage of the method was the high cost of the additives used and the content of alkaline compounds in the briquettes, which is highly undesirable for the blast furnace.
Recovery of Value-Added Materials from Iron Ore Waste and Steel Processing Slags with Zero-Waste Approach and Life Cycle Assessment
Published in Hossain Md Anawar, Vladimir Strezov, Abhilash, Sustainable and Economic Waste Management, 2019
Hossain Md Anawar, Vladimir Strezov
The Fe-mineral ores contain impurities of phosphorus, sulphur and high alkali, as well as impregnations of waste rock. The magnetic separation of iron minerals and washing iron ores leaves the tailings and wastewater, consisting mostly of silicate rock and clay that are not expected to be hazardous (US EPA, 1988). During iron making, iron ore, coke, heated air and limestone or other fluxes are fed into a blast furnace. Blast furnace slag contains oxides of iron, silicon, aluminum, calcium, magnesium and manganese, along with other trace elements. There are three types of blast furnace slag: air-cooled, granulated, and pelletised (or expanded) (US EPA, 1990). Blast furnace slag should normally be generated at a rate of less than 320 kg/t of iron, with a target of 180 kg/t. The impurities in the feed materials control the generation of blast furnace slag. Cokeless iron making procedures are currently being studied and, in some places, implemented such as the Japanese Direct Iron Ore Smelting (DIOS) process that produces molten iron from coal and previously melted ores (USEPA, 1995). This process has the effect of cutting the costs of molten iron production by about 10% and reducing emissions of carbon dioxide by 5–10% (Furukawa, 1994).
Ferrous Metals Waste Production and Recycling
Published in Sehliselo Ndlovu, Geoffrey S. Simate, Elias Matinde, Waste Production and Utilization in the Metal Extraction Industry, 2017
Sehliselo Ndlovu, Geoffrey S. Simate, Elias Matinde
While the blast furnace is expected to remain the world’s principal source of iron units for the steelmaking process as long as adequate supplies of suitable iron ores and coking coals remain available at competitive cost, these alternative ironmaking processes are slowly gaining traction as serious contenders to the blast furnace process, particularly for small-sized local and regional markets (Fruehan, 1993; Zervas et al., 1996a,b; Feinman, 1999; IAE Clean Coal Centre, 2004; Anameric and Kawatra, 2009; Gordon and Kumar, 2013; Remus et al., 2013). Figure 4.4 shows a schematic representation of the primary and alternative ironmaking processes (Remus et al., 2013).
Study on semi-coke as an alternative fuel for blast furnace injection coal
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2022
Xiaoxiong Wu, Shijie Wang, Hongming Fang, Zhen Xu, Peilin Che, Alex Kojo Acquah
Blast furnace injection technology can significantly reduce fuel consumption costs in the process of blast furnace ironmaking, and its application in the steel industry has achieved good economic effects, blast furnace injection coal mainly includes anthracite, low volatile bituminous coal, and high volatile bituminous coal. However, as the price of high-quality coal increases year by year, the cost of blast furnace injection coal has also increased accordingly. In order to reduce the coke ratio and production costs, semi-coke will be used to replace part of the fuel during coal blending (Du and Yang 2013). In recent years, the environmental protection policy has gradually become stricter and the pressure of the environmental protection has continued to increase. Semi-coke is considered to be a fuel of interest in the steel industry to replace blast furnace injection coal. Blast furnace injection of semi-coke meets the requirements of the energy saving and emission reduction, conforms to the energy optimization policy, makes rational and efficient use of coal resources, and promotes the development and utilization of coal conversion products.
Red Mud: Fundamentals and New Avenues for Utilization
Published in Mineral Processing and Extractive Metallurgy Review, 2021
Because of the typically high weight percent of iron in red mud, many researchers have sought to extract this value from the waste using a variety of methods. Removing iron from red mud effectively reduces the total amount of red mud that is being discharged. In some cases, iron oxides account for half of the composition of red mud. If the iron is removed, up to half of the weight of red mud is utilized as a value-added product. Discovering alternative methods to produce iron are very important to the mineral processing industry because currently the majority of iron production lies on the shoulders of the blast furnace. Blast furnaces need to be built to such a large scale to be economically feasible that anytime a furnace fails, there are serious economic consequences.
Gasification and kinetic study on metallurgical cokes in CO2-N2-H2O and CO2-N2 atmosphere
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Xiangyu Fan, Chao Li, Mingdeng Wang, Yang liu, Yajie Zheng, Yang liu, Xiangyun Zhong, Guozhong Xu, Yaru Zhang, Yifei Feng, Bin Bai, Xuhui He, Jinfeng Bai
The main goal of blast furnace ironmaking is to obtain the highest energy utilization efficiency, highest gas utilization rate, and lowest fuel ratio. Therefore, the following conditions should be met: the thermal balance and the material determine the fuel ratio to the greatest extent; the reduction capacities of gases are used to achieve the maximum utilization rate of gases; blast furnace operations should provide sufficient conditions for aerodynamics, heat transfer, and chemical reaction kinetics (Xiang, Xl, and Jl 2020). Cokes in a blast furnace will be subjected to thermal stress caused by combustion, mechanical stress caused by tuyere gas, and gasification reaction with gases (CO2 and H2O). Gasification reaction has become the main influencing factor of the coke quality in these functions due to its dissolution and structural damage to coke (Gupta et al. 2007). Zou et al. (2006) studied the kinetic parameters of coke in CO2 gas. According to the kinetic data fitting, the CO2 gasification reaction order is 0.54–0.88. Coke gasification and its influence on coke’s dissolution loss after adding hydrogen-rich gases to blast furnaces is vital for the development of a hydrogen-rich blast furnace. Besides, the kinetic analysis of coke gasification is essential for understanding gasification behaviors and mechanisms. However, according to thermodynamic analysis, most H2 react with iron ores after being injected into the blast furnace, which produces H2O instead of directly reacting with carbons to degrade cokes. Thus, obtained outcomes do not fully show cokes’ gasification dynamics in hydrogen-rich blast furnaces (Bruno et al. 2017).