The converter steelmaking process generates a large amount of dust removal ash, which has fine particle size and contains many harmful substances. Direct discharge or stockpiling can pollute the environment. Currently, steel plants often return it to sintering ingredients to recycle beneficial components such as Fe and Ca. However, this practice adversely affects the quality of sintering mixtures, permeability, control of flue gas pollutants, sintering heat balance, sinter quality, blast furnace lifespan, and furnace conditions. Therefore, a specialized study has been conducted on the rational utilization of converter dust removal ash to reduce steelmaking costs. This article focuses on the technological innovation and application practices of cold-bonded briquetting for dust removal ash. Through a series of optimizations in equipment, processes, and material ratios, it not only fully utilizes valuable resources such as iron and calcium in the dust removal ash, reducing smelting costs, but also addresses issues of resource waste and environmental pollution caused by waste materials to a certain extent. This has created significant economic and social benefits, promoting the sustainable development of the steel industry. Keywords: Converter dust removal ash, Cold-bonded briquettes, Technological innovation
1 Project Background The iron grade in steelmaking dust removal ash is relatively high. In recent years, it has been recycled as a blended material in the sintering process. However, this method has drawbacks such as a long process flow and inconvenience in transportation and usage. Moreover, due to the increased use of scrap steel in steelmaking by domestic steel enterprises, the zinc content in dust removal ash is relatively high, adversely affecting the smooth operation of blast furnaces. This has prompted a re-evaluation of the reuse of steelmaking dust removal ash: on one hand, the cold-pressing briquetting method can avoid the issue of dust dispersion during transportation and use; on the other hand, by adding cold-pressed briquettes of steelmaking dust removal ash back into converter steelmaking, the recycling process is significantly shortened, and the adverse effects of harmful components in the dust removal ash on blast furnaces are avoided. This project was carried out through a combination of technology introduction and integrated innovation. The overall approach is to learn from and apply existing key theories, technologies, equipment, and control methods domestically and internationally, optimizing the application of cold-bonded briquetting technology for dust removal ash to establish an advanced application demonstration in the industry. 2 Research on the Process and Equipment of Cold-Bonded Briquetting for Dust Removal Ash This project mainly consists of four parts: raw material preparation and digestion, batching and mixing, briquetting and primary screening, and drying and secondary screening. The production process flow: dust removal sealed tank storage → digestion of dust removal ash → addition to the mixing system → binder batching → mixing and homogenization → briquetting → drying of briquettes → finished briquettes storage → delivery to steelmaking. The cold-pressed briquette project can be summarized into the ash unloading system, digestion system, batching system, and briquetting system during the production process.