Simulation and experimental research on top blown burner lance used for chrome ore smelting reduction process

Chrome ore smelting reduction process in converter for crude stainless steel production has won increasing attention because of utilizing cheap chrome ore as raw material instead of ferrochromium alloy, which can reduce the production cost significantly. Thermodynamic and kinetic mechanisms of chrome ore smelting reduction have been well investigated by previous studies. How to improve the dissolution rate and reduction rate of chrome ore in actual production is the key problem of industrial application. In this paper, a method of using combustion flame to convey chrome ore powder was studied. Numerical simulation works were carried out to study the structure of top blown burner lance blowing propane combustion flame and chrome ore powder simultaneously. Optimal design of burner lance was confirmed and made for experiment. Flame measurement experiment was carried out to study the flame characteristics before and after powder addition, indicating that the addition of powder helps to prolong the flame length. Then a pilot experiment of chrome ore smelting reduction was carried out in a 0.5 ton submerged arc furnace, metallurgical effects under conditions with and without combustion flame were compared and analyzed. The results showed that the combustion flame can not only preheat the chrome ore powder, but also heat the molten slag of impact zone, obtaining better reaction rate and higher chrome ore yield.