Abstract:
Stainless steel dust is generated as a secondary solid waste during conventional steelmaking processes. It contains valuable metal components such as iron, chromium, and nickel, and is characterized by fine particle size and complex chemical composition, making it prone to causing environmental pollution. Chromite is recognized as an important and scarce natural resource, containing valuable metal elements including iron and chromium. Traditional smelting processes for chromite are faced with triple challenges of high pollution, high energy consumption, and high cost. In this study, stainless steel dust and chromite ore were utilized as raw materials to prepare carbon-containing hot-pressing briquettes through hot-pressing technology, aiming to provide high-quality feedstock for efficient reduction processes such as the rotary hearth furnace and achieve effective recovery of metal components including iron, chromium, and nickel. This approach was designed not only to enhance the smelting efficiency of chromite and reduce dependence on the import of primary ores, but also to mitigate environmental threats caused by solid waste accumulation, thereby aligning with the requirements of solid waste resource utilization and green metallurgy. This paper systematically investigated the effects of key process parameters including raw material ratio, hot-pressing briquetting temperature, hot-pressing briquetting holding time, and hot-pressing briquetting pressure on the compressive strength of carbon-containing hot-pressing briquettes made from stainless steel dust and chromite. It also revealed the mechanisms by which these conditions influence the compressive strength of the carbon-containing hot-pressing briquettes. Through experimental optimization, the optimal preparation parameters were determined, providing a feasible technical solution for the resource recovery of stainless steel dust and chromite. The experimental results show that the optimal formulation for preparing carbon-containing hot-pressing briquettes from stainless steel dust and chromite ore is determined as a 60% to 40% ratio between the two, with an external addition of 27.97% coke coal. The optimal processing parameters are identified as a forming temperature of 250 ℃, a forming pressure of 35 MPa, and a holding time of 2 min. Under these conditions, the compressive strength of the carbon-containing hot-pressing briquette reaches 756.7 N, which meets the strength requirement for charging into a rotary hearth furnace. This work provides a theoretical basis and a novel approach for the synergistic utilization of iron-bearing resources.