Abstract: Against the backdrop of the global "carbon peaking and carbon neutrality" goals, as a field of high carbon emissions, the steel industry urgently needs to develop green and low-carbon metallurgy technologies to reduce carbon emissions. Electrolytic iron technology has emerged as a key research direction for low-carbon metallurgy, as it directly utilizes green electricity to drive reduction reactions and reduces fossil energy consumption associated with traditional blast furnace ironmaking. The sulfate-system electrolytic iron process exhibits promising industrial application potential due to its simplicity and low cost. However, the morphological control of iron deposits and impurity removal during electrolysis remain critical issues restricting its development. In this study, the preparation of electrolytic iron was conducted in a sulfate electrolyte system using an iron plate as the anode. The effects of electrolysis time (5~180 min), electrolysis temperature (20~80℃), Fe2+ concentration (20~100 g/L), current density (400~1200 A/m2) and cathode material (Ti, Cu, Ni, Al, Fe) on the morphology, purity, and current efficiency of electrolytic iron were systematically investigated. The results showed that the titanium cathode could significantly inhibit impurity introduction. Under the optimized conditions of an electrolysis temperature of 80℃, Fe2+ concentration of 60 g/L, current density of 1000 A/m2, and electrolysis time of 30 min, electrolytic iron products with excellent morphology and easy stripping were obtained. XRD, SEM-EDS, and dissolution analysis indicated that the as-prepared product was dominated by pure iron via synergistic regulation of multiple parameters. It exhibited a stepped morphology with clear grain boundaries, closely packed particles, and extremely few pores. The maximum purity achieved by spot scanning was 99.97wt%, and the iron purity measured by dissolution analysis was 99.94wt%. Under the optimized conditions, the current efficiency exceeded 97%, and the direct current consumption for electrolysis was approximately 4.35 kWh/kg-Fe. This research not only provides a technical path that has both cost-effective and performance advantages for the industrial production of electrolytic iron, but also provides theoretical basis and practical reference for the development of low-carbon metallurgy technology, which is of great significance to promoting the green transformation of the steel industry.

Key words: sulfate electrolyte system, electrolytic parameters, current efficiency, deposition morphology

摘要： 本研究基于硫酸盐电解液体系，采用铁板作为阳极，系统考察了电解时间(5~180 min)、电解温度(20~80℃)、Fe2+质量浓度(20~100 g/L)、电流密度(400~1200 A/m2)及阴极材料(钛、铜、铝、镍、铁)等对电解铁形貌、纯度及电流效率的影响。结果表明，钛阴极可显著抑制杂质引入，在电解温度80℃、Fe2+浓度60 g/L、电流密度1000 A/m2、电解时间30 min的优化条件下，可制得形貌优异、易于剥离的电解铁产品。X射线衍射(XRD)、扫描电子显微镜-能谱(SEM-EDS)与溶样法分析表明，经多参数协同调控，所得产物主要物相为纯铁，呈现晶界清晰、颗粒排布紧密、孔隙极少的阶状形貌；点扫最高纯度可达99.97wt%，溶样法测得铁纯度为99.94wt%。经计算，优化条件下电流效率高达97%以上，电解直流电耗约为4.35 kWh/kg-Fe。该工艺有望为电解铁工业化生产提供兼具成本效益与性能优势的技术路径。

关键词: 硫酸盐电解液体系, 电解参数, 电流效率, 沉积形貌