A new analysis method based on serial sectioning and three-dimensional(3 D)reconstruction was developed to characterize the mineral microstructure of iron ore sinter.Through the 3 Dreconstruction of two types of iron ore sinters,the morphology and distribution of minerals in three-dimensional space were analyzed,and the volume fraction of minerals in a 3 Dimage was calculated based on their pixel points.In addition,the microhardness of minerals was measured with a Vickers hardness tester.Notably,different mineral compositions and distributions are obtained in these two sinters.The calcium ferrite in Sinter 1 is dendritic with many interconnected pores,and these grains are crisscrossed and interwoven;the calcium ferrite in Sinter 2 is strip shaped and interweaves with magnetite,silicate and columnar pores.The calculated mineral contents based on a two-dimensional region are clearly different among various layers.Quantitative analysis shows that Sinter 1 contains a greater amount of calcium ferrite and hematite,whereas Sinter 2 contains more magnetite and silicate.The microhardness of minerals from highest to lowest is hematite,calcium ferrite,magnetite and silicate.Thus,Sinter 1 has a greater tumbler strength than Sinter 2. A new analysis method based on serial sectioning and three-dimensional (3 D) reconstruction was developed to characterize the mineral microstructure of iron ore sinter. Through the 3 Dreconstruction of two types of iron ore sinters, the morphology and distribution of minerals in three- dimensional space were analyzed, and the volume fraction of minerals in a 3 Dimage was calculated based on their pixel points. In addition, the microhardness of minerals was measured with a Vickers hardness tester. Notably, different mineral compositions and distributions are obtained in these two sinters.The calcium ferrite in Sinter 1 is dendritic with many interconnected pores, and these grains are crisscrossed and interwoven; the calcium ferrite in Sinter 2 is strip shaped and interweaves with magnetite, silicate and columnar pores. The calculated mineral contents based on a two -dimensional region are clearly different among various layers. Quantitative analysis shows that Sinter 1 contains a greater amount of calc ium ferrite and hematite, whereas Sinter 2 contains more magnetite and silicate. The microhardness of minerals from highest to lowest is hematite, calcium ferrite, magnetite and silicate.Thus, Sinter 1 has a greater tumbler strength than Sinter 2.