Effect Of Additives On Properties Of Imported Iron Concentrate Pellets

Due to the wide range of iron ore sources and large quality differences in China,the production and quality performance of pellets fluctuate greatly.Therefore,many domestic iron and steel enterprises stabilize the production and performance of pellets by increasing the amount of bentonite.However,excessive amount of bentonite will cause adverse effects such as increased coke ratio of blast furnace,increased carbon emission and increased smelting cost.So,it is imperative to reduce the dosageof bentoniteand improve the TFe grade and metallurgical properties of pellets.In this experiment,four kinds of imported iron concentrate powder,A,B,C and D,which are commonly used in China,were selected to prepare pellets.The water content of pellets,bursting temperature,drop strength of pellets,compressive strength of pellets,compressive strength of roasted pellets,reducibility and TFe grade of pellets were measured respectively to compare and analyze the performance differences of four kinds of pellets.The experimental results show that the compressive strength of roasted pellets of PA# is 3587.0 N/P,which is the highest among the four pellets.PB#pellets have the best pellets with the compressive strength 10.8N/P and the drop strength 6.2 times /(0.5m).The TFe grade of PC# pellets was the highest at 67.16%,and the strength of preheated pellets was the lowest at 558.6 N/P.The compressive strength and drop strength of pellets were only4.8 N/P and 4.6 times/(0.5m).Because the TFe grade of PC# pellets is the highest,it has better economic benefit.Therefore,iron concentrate C was selected as raw material to explore the influence of the ratio of A,B and C pellet additives on the performance of pellets.The results show that with the increase of the ratio of a and b bentonite,the drop strength,compressive strength of pellets and the compressive strength of roasted pellets all increase,and the effect of b bentonite on the compressive strength of pellets is better.With the increase of the ratio of c composite binder,the compressive strength of pellets increased slightly,while the compressive strength of roasted pellets decreased significantly.The lowest compressive strength of roasted pellets was only 2061.0 N/P at the ratio of 3.0%.The pellet performance of a and c additive mixed with the pellets is obviously higher than that of single additive with the same ratio.When 1.5% a bentonite and 0.5% c composite binder are used together,the pellets have the best performance,the pellets drop strength is 6.1 times /(0.5m),the roasted pellets compressivestrength is 3043.0 N/P,and the reducibility is 79.51%.