Integral Quality Index for Iron Ore Raw Materials and Cast Iron Composition Prediction

The main direction of research on iron ore raw material metallurgical properties in recent decades is the search for an adequate description of the "natural" relationships between the characteristics of iron ores and the behavior of sinter and pellets obtained from these ores. An integrated index of iron ore raw material quality is proposed linking metallurgical, physical and mechanical properties of iron ores with slag parameters and gas dynamics of the blast furnace process. An important task is to find the relationship of these indices with reduction processes, blast furnace smelting mass and heat exchange processes, and to predict cast iron chemical composition. Data bases of key performance indices of PAO NLMK blast furnaces for the period 2013-2018 are compiled and analyzed. It is established that under conditions of stable blast furnace operation using raw materials from sinter and pellets with combined blast dependences for sulfur and silicon content in cast iron on an integral index of iron ore raw material quality are determined by the index for the level of degree of direct reduction process development. Relationships are investigated and established for correlation of these parameters and characteristics making it possible to accomplish effective control of blast furnace smelting under stable operation conditions. They may be used in logical-quantitative expert systems for predicting and monitoring blast furnace processes.