钢渣中含有的金属铁及其氧化物是一种高附加值的可再生资源，同时钢渣又可以作为矿物掺合料用在建材行业中。钢渣经不同冷却处理工艺，物相发生演变，从而影响钢渣中铁的回收及尾渣的胶凝活性。为了提高钢渣中铁资源的回收和尾渣的有效利用，文中针对热泼、辊压破碎-有压热闷和辊压破碎-热泼3种不同处理工艺下的钢渣，利用岩相分析、X射线衍射分析仪（XRD）、扫描电子显微镜-能量色散谱仪（SEM-EDS）、化学物相选择溶解等手段对不同处理工艺下钢渣的铁相分布及富集状态进行研究，并测定其磁选粉收得率和铁品位，以及尾渣的胶凝活性。结果表明：热泼工艺下钢渣中金属铁更易富集沉积，铁相主要以FeO均匀分布在RO相和铁酸盐相中，相中Fe占比较少，磁选粉收得率较高，但铁品位较差，分别为32.22%和33.43%；辊压破碎-有压热闷渣中未见明显金属铁粒，但含铁相中Fe占比较多，磁选粉收得率低，但铁品位较高，分别为28.37%和37.12%；辊压破碎-热泼渣中，铁相主要以Fe₂O₃形式存在于铁酸钙相和硅酸盐相，相中Fe占比较多，且含有磁性铁Fe₃O₄，磁选粉收得率高，铁品位也高，分别为37.60%和39.69%。辊压破碎-有压热闷渣中C₂S含量相对更多且发育较好，胶凝活性高，7 d及28 d活性指数分别为78%和92%；辊压破碎-热泼渣的7 d活性指数较低，为66%，但28 d活性指数增长到92%；热泼渣的胶凝活性居中。

Steel slag contains metallic iron and its oxide, which are high value‐added renewable resources, and it can be utilized as a mineral admixture in the building materials industry. After different cooling treatment processes, the phase of steel slag evolves, thus affecting the recovery of iron in steel slag and the cementitious activity of tailings. In order to improve the recycling of iron resources in steel slag and the effective utilization of tailings, this paper studied the steel slag of three different treatment processes, namely, hot splash, roller crushing‐pressurized hot stewing and roller crushing‐hot splash. It used petrography analysis, XRD, SEM‐EDS, and chemical phase‐selective dissolution, and other methods to analyze the distribution of the iron phases and the state of enrichment of steel slags, and to determine the rate of magnetic separation powder and iron grade, and the cementitious activity of tailings. The results show that: the metal iron is easier to be enriched and deposited under the hot splash process, and the iron phase is mainly in the form of FeO uniformly distributed in the RO phase and the ferrite phase, with less Fe in the phase, and the yield of magnetic separation powder is higher, but the grade is poorer, which is 32.22% and 33.43%, respectively. After roll crushing‐pressurized hot stewing, no obvious metal iron particles can be seen in the slag; Fe in the phase accounts for more, and the yield of the magnetic separation powder is low but the grade is higher, which is 28.37% and 37.12%, respectively; after roll crushing‐hot splashing, the iron phase mainly exists in calcium ferrite phase and silicate phase in the form of Fe₂O₃, Fe in the phase accounts for more and contains Fe₃O₄, and the magnetic separation powder has high yield and high iron grade, which is 37.60% and 39.69%, respectively. Under roll crushing‐pressurized hot stewing, the C₂S content in steel slag is relatively more and better developed, and has high cementitious activity, 7 d and 28 d activity index of tailings is 78% and 92%, respectively; the 7 d activity index of the roll crushed‐hot splash slag is low at 66%, but the 28 d activity index grows to 92%; the cementitious activity of the hot splash slag is in the middle.