Innovative approaches for recycling of DRI fines in modern direct reduction processes
摘要
To maximize resource efficiency in the direct reduction ironmaking process, effectively recirculating DRI fines is essential. These fines, which account for 1–2% by weight of DRI production, are generated during handling, production, and transportation processes. The DRI fines, rich in iron and comprised of finer size fractions, present a significant opportunity for innovation; however, their effective recycling poses challenges without proper agglomeration. Briquetting emerges as a highly promising solution to this challenge. This research explores the application of both organic and inorganic binders in briquetting DRI fines, aiming to unlock their full potential. The H2-based reduction behavior of the resulting briquettes is analyzed, utilizing a reduction process powered by 100% H2. The impact of various binders on critical parameters such as mechanical strength, moisture content, and compaction pressure of the briquettes is explored. The optimized briquettes undergo rigorous hydrogen-based reduction through thermogravimetric analysis (TGA), followed by comprehensive characterization using XRD, and LECO methods. Impact of carbon addition on the mechanical strength of the briquettes was also investigated. Among the various binders tested, the optimal combination for enhancing the mechanical strength of DRI fines briquette was determined to be 2% polyacrylamide binder with 0.2–0.8% sodium silicate. Furthermore, the incorporation of 5% biocarbon into DRI fines effectively maintained mechanical integrity, emphasizing the critical role of binders in producing durable briquettes suitable for industrial processes. This research contributes to advancing sustainable practices in the industry and paves the way for a greener future in iron and steel manufacturing.