The influence of the physicochemical properties of the slag binders on the structure of the calcined pellets was studied. Different types of slag binders are considered and the dependences of viscosity, surface tension of the minimum cooling rate on the basicity and oxidation state of slag inclusions are obtained. The kinetics of the reduction of pellets with different types of structures under non-isothermal conditions was studied using an OD-102 derivatograph and a mineralogical analysis of partially reduced pellets heated to different temperatures was performed. Using mineralogical analysis and IR spectroscopy, the main types of structures in the pellets were isolated and studied. It is shown that the nature of distribution and the type of slag binders in the structure of the pellet has a decisive influence on the course of the recovery process and the properties of agglomerated products. The results obtained in this work are of certain practical interest, since by analyzing the melt by composition of the charge and studying the properties of liquid silicates, it is possible to predict the physical structure of the calcined pellets and, based on this, develop pellet heat treatment modes that provide pellets with the required metallurgical properties.