A Holistic and Experimentally-Based View on Recycling of Off-Gas Dust within the Integrated Steel Plant

Abstract

Ore-based ironmaking generates a variety of residues, including slags and fines such as dust and sludges. Recycling of these residues within the integrated steel plant or in other applications is essential from a raw-material efficiency perspective. The main recycling route of off-gas dust is to the blast furnace (BF) via sinter, cold-bonded briquettes and tuyere injection. However, solely relying on the BF for recycling implicates that certain residues cannot be recycled in order to avoid build-up of unwanted elements, such as zinc. By introducing a holistic view on recycling where recycling via other process routes, such as the desulfurization (deS) station and the basic oxygen furnace (BOF), landfilling can be avoided. In the present study, process integration analyses were utilized to determine the most efficient recycling routes for off-gas dust that are currently not recycled within the integrated steel plants of Sweden. The feasibility of recycling was studied in experiments conducted in laboratory, pilot, and full-scale trials in the BF, deS station, and BOF. The process integration analyses suggested that recycling to the BF should be maximized before considering the deS station and BOF. The experiments indicated that the amount of residue that are not recycled could be minimized.

Sustainable Utilization of Metals-Processing, Recovery and Recycling

“…Consumer and production wastes show excellent recovery opportunities for this group of metals. That is why eleven papers deal with the recovery of base metals [12][13][14][15][16][17][18][19][20][21][22] and one of precious metals [23].…”

Risk Assessment and Mitigation Model for Overseas Steel-Plant Project Investment with Analytic Hierarchy Process—Fuzzy Inference System

“…Although most literature dedicated to the steel manufacturing process has been on improving the efficiencies of the production process (e.g., [3][4][5][6][7]), as early as 1985, investigations were taking place on the effect uncertainty has on the steel industry and associated investments [9]. Min [1], Price et al [10], and Bucur et al [11] have all investigated uncertainties in steel manufacturing from a global perspective.…”

“…Globally, countries are implementing stricter environmental policies which current steel processes will likely not be able to meet in the near future [2]. In addition to these environmental and energy consumption problems, new steel technologies are being developed to improve existing steel processes [3][4][5][6][7]. The inherent challenges of executing projects internationally, compounded by both the execution and exportation new technologies, equates to executing steel-plant construction overseas an activity riddled with uncertainties and risk [8].…”

The Potential of Recycling the High-Zinc Fraction of Upgraded BF Sludge to the Desulfurization Plant and Basic Oxygen Furnace

“…Considering the results in the technical-scale experiments with pellets, the rise of melt-in problems Based on the above, the total amount of briquettes that could be recycled to the steel shop, including both the HM deS plant and BOF, was estimated to 14,100 metric tons per year. Depending on which method is used for upgrading the BF sludge, the amount of solids reporting to the high-zinc fraction varies [23]. Consequently, this determines the required wt.% of the high-zinc fraction in the briquette recipe that results in the complete recycling of this fraction.…”