Influence of Different Ratios of the United States Iron Concentrate on Metallurgical Performance and Microstructure of Pellets
As China's iron and steel industry evolves towards intensive,large-scale,and low-carbon emission operations,the standards for furnace feedstock continually escalate.Pellet ore,owing to its efficiency,energy conservation,and environmental benefits,has emerged as a pivotal direction,with the demand for high-quality pellets steadily rising.However,the inferior quality of domestic iron ore resources necessitates the prevalent use of imported iron ore concentrate for pellet production.American iron ore concentrate,a newly imported mineral,boasts a low grade but high alkaline oxide content,and its large-scale application remains unexplored.By incorporating American iron ore concentrate,the physical and metallurgical characteristics of iron ore powder can be modulated to enhance the metallurgical properties of pellet ore.This study delves into the influence of varying ratios of the United States iron ore concentrate on the metallurgical properties and microstructure of pellet ores through a comprehensive suite of experiments,including pellet mixing,reductivity testing,reduction and expansion analysis,and mineral microscopy.The objective is to refine the mixing structure,elevate the performance of raw and finished balls,and elucidate the underlying mechanism of pellet ore formation.The results indicate that the incorporation of the United States iron ore concentrates significantly influences the ball-making process.As the proportion of the United States concentrates increases from 0%to 35%,there is a notable enhancement in ball-making and ball return rates,as well as an increase in ball disc frequency.Notably,at a 20%ratio of the United States concentrates,the overall quality of the pellet ore is optimized,satisfying the metallurgical properties and compressive strength standards required for blast furnace production.Furthermore,the elevation in the United States concentrate content leads to a gradual decrease in hematite crystal development within the pellet ore,accompanied by a rise in the formation of magnesia ferrite and calcium ferrite.This microstructural change is macroscopically manifested by a decline in compressive strength and an improvement in metallurgical performance.The findings of this study offer theoretical justification and technical guidance for the efficient utilization of the United States iron ore concentrate resources.By minimizing the amount of binding agent required for balling,ensuring the robustness of raw and finished balls,and enhancing the reducing properties of pellets,this approach contributes to elevating the low-carbon and environmentally friendly practices of China's iron and steel industry,thereby fostering its sustainable development.
the United States iron ore concentratepelletized oremetallurgical propertiescompressive strengthhematiteraw pelletsreductive expansiondegree of reduction
万方数据
维普
