Magnesian Flux Pellets Roasting Consolidation Mechanism Research

Pellets,for the high iron grade and the advantages of granularity uniform,become high-quality materials of blast furnace iron making in recent years.However,the acid pellet has many defects for its strength and metallurgical properties.In order to optimize burden structure and improve the quality of acid pellet,it is meaningful to study the influence of the change of alkalinity and magnesium content of pellet strength and metallurgical properties by adding magnesium and calcium.To provide the theoretical basis of application of fluxed pellets in iron smelting industry,and has great significance for the sustainable development of iron and steel enterprises.With calcium magnesium additive way pelletizing by local magnetite pellet roasting simulation reaction with Fact Sage thermodynamic software,while the use of liquid nitrogen adsorption instrument,X-ray diffraction,thermogravimetric analyzer,mineral phase analysis to detect performance analysis of detection methods of mixed raw materials and finished pellet,variation of adding calcium and magnesium flux pellet strength and metallurgical properties,roasting consolidation mechanism through the migration rule of Ca²⁺ and Mg²⁺ on fluxed pellets.According to the study of the performance of alkaline pellets,with the increase of the amount of calcium,the mechanical strength and comprehensive strength of pellets were increased first and then decreased.The increase of the glass quality makes the performance of the finished ball become worse and worse.And the reduction of pellets demonstrates the good condition first after the bad trend of change.When the roasting temperature of pellets is 1250?with basicity 1,the performance of pellets is optimal.According to the study of the performance of ball pellets: with flux alkalinity at 1 mg and the dosage of Mg at 1%,pellet ball mechanical strength and compressive strength of pellets reached the maximum.And when the basicity is controlled at 1.0,and the content of magnesium is 1%,metallurgical properties of the ball pellets are optimal.According to the study of fluxed pellet roasting consolidation mechanism: with the alkalinity change,Ca²⁺ with low melting point liquid forms of migration,is embedded in the hematite hematite crystal,and finally the effect is good and the strength of the pellets increases.The increase of calcium ferrite content promotes the migration of Mg²⁺,and the mineralization of Mg O non mineralized,but too much liquid also hinders the crystallization of hematite,and the growth of pellet strength is limited.