Research progress on resource utilization of metallurgical oil-containing solid wastes

Metallurgical oil-containing solid wastes have both pollution potential and resource value, and their efficient disposal and resource utilization represent an important direction for promoting green and low-carbon development in the metallurgical industry. This paper focuses on typical metallurgical oil-containing solid wastes including rolling oil bearing sludge, oily copper scraps, and oily aluminum scraps. It systematically reviews their sources, compositional characteristics, generation scales, and management requirements. The review emphasizes the research progress in collaborative utilization pathways through return to metallurgical processes such as sintering, coke making, blast furnace injection, rotary hearth furnace treatment, and smelting, as well as on deoiling pretreatment technologies including chemical hot washing, solvent extraction, oxidation, pyrolysis, centrifugal separation, and distillation. Existing studies show that co-utilization in metallurgical processes offers advantages such as large treatment capacity, high metal recovery rates, and easy integration with existing production processes. However, due to factors such as the presence of oil in raw materials and environmental pollution caused by heat treatment, oily solid wastes are usually difficult to be directly utilized in large proportions. Deoiling pretreatment facilitates oil solid separation and improves material properties, serving as a key prerequisite for enhancing compatibility with these processes, yet it still faces bottlenecks including high cost, energy consumption, secondary pollution, and insufficient deoiling depth. Based on analysis of the applicability and limitations of various technologies, this paper points out that the resource utilization of metallurgical oil-containing solid wastes require the construction of differentiated technical routes according to parameters such as oil mass fraction, viscosity, and metal value. Finally, it discusses future research directions including graded utilization tailored to different wastes characteristics, demand oriented deoiling and conditioning technologies, and synergistic recovery of oil and metals. This paper aims to organize the technical framework for the disposal and resource utilization of such solid wastes, clarify the application characteristics and development directions of various technologies, and provide a reference for research on multi component synergistic recovery and utilization.