Metallurgical Wastes as Resources for Sustainability of the Steel Industry

Advancements and sustainable strategies for the treatment and management of wastewaters from metallurgical industries: an overview

Metallurgy is pivotal for societal progress, yet it yields wastewater laden with hazardous compounds. Adhering to stringent environmental mandates, the scientific and industrial sectors are actively researching resilient treatment and disposal solutions for metallurgical effluents. The primary origins of organic pollutants within the metallurgical sector include processes such as coke quenching, steel rolling, solvent extraction, and electroplating. This article provides a detailed analysis of strategies for treating steel industry waste in wastewater treatment. Recent advancements in membrane technologies, adsorption, and various other processes for removing hazardous pollutants from steel industrial wastewater are comprehensively reviewed. The literature review reveals that advanced oxidation processes (AOPs) demonstrate superior effectiveness in eliminating persistent contaminants. However, the major challenges to their industrial-scale implementation are their cost and scalability. Additionally, it was discovered that employing a series of biological reactors instead of single-step biological processes enhances command over microbial communities and operating variables, thus boosting the efficacy of the treatment mechanism (e.g., achieving a chemical oxygen demand (COD) elimination rate of over 90%). This review seeks to conduct an in-depth examination of the current state of treating metallurgical wastewater, with a particular emphasis on strategies for pollutant removal. These pollutants exhibit distinct features influenced by the technologies and workflows unique to their respective processes, including factors such as their composition, physicochemical properties, and concentrations. Therefore, it is of utmost importance for customized treatment and disposal approaches, which are the central focus of this review. In this context, we will explore these methods, highlighting their advantages and characteristics.

Study on the Mechanical Properties and Mechanism of a Nickel-Iron Slag Cement-Based Composite under the Action of Sodium Sulfate

The accumulated amount of nickel-iron slag has increased with the rapid development of the nickel-iron industry. To determine a method for comprehensively utilizing nickel-iron slag, triaxial compression tests of nickel-iron slag cement-based composite materials under the action of sodium sulfate were conducted, and the effects of the sodium sulfate concentration on the stress-strain relation, shear strength, cohesion, and internal friction angle of the composite materials were analyzed. In addition, the influence mechanism of the nickel-iron slag content and sodium sulfate concentration on the composite was examined. The results revealed that the stress-strain curve of the nickel-iron slag cement-based composites reflected softening. With the increase in the sodium sulfate concentration, the brittleness increased, while the shear strength, cohesion, and internal friction angle decreased; the addition of nickel-iron slag slowed down the rate at which these parameters decrease. Scanning electron microscopy images revealed that nickel-iron slag can improve the internal structure of the cement composite soil, enhance its compactness, and improve its corrosion resistance. The optimum nickel-iron slag content of 14% can improve the cementitious composites' resistance to sodium sulfate erosion in terms of solid waste utilization and cementitious soil performance. The results obtained can provide technical parameters for preparing and designing cement-based composite materials as well as certain theoretical significance and engineering reference value.

3-Methyl-1-phenyl-4-thioacetylpyrazol-5-one

The novel compound 3-methyl-1-phenyl-4-thioacetylpyrazol-5-one is obtained in excellent yield via a thionation of the corresponding oxygen analogue. The product is isolated in pure form using column chromatography and is characterised using 1D and 2D NMR experiments, ATR IR and HRMS spectra, and single-crystal XRD.