Basic Research On Optimizing Quality Of Pellet Of Lianyuan Steel

In order to solve the poor quality of pellet of Lianyuan steel,improve the comprehensive utilization of pellet material and reduce the cost of production,In this paper,four kinds of iron ore concentrates(Hunan iron ore,Chile iron ore,Iran iron ore and Jiangxi iron ore)and two kinds of bentonite(Huajia bentonite and Changde bentonite)which were provided by Lianyuan Steel,and the influences of different ores blending of pelletizing raw material(types and ratio of bentonite and additives)on the quality of pellet were investigated in this paper.when the ratio of Huajia bentonite was 2.0 %,the results were as following:(1)From the pelletizing experiment with single iron concentrate,we can know that the comprehensive quality of Hunan ore and Chile ore is better than others,followed by is Iranian ore,Jiangxi ore is the worst,the drop strength and the roaster strength is 4.4?4905 N,5.3?3647 N,4.2?2988 N and 3?1776 N;(2)The pelletizing experiment of two iron concentrate shows that the combination of Hunan and Chile is the best,the drop strength and the roaster strength is ranging from 4.3-5.0 and 2955-4139 N combination of Jiangxi and Iran is the worst,were less than 4 and less than 2700 N and the more the ratio of good quality iron ore concentrate increases,the better the quality of pellet will be;(3)when three iron ore concentrate mixed to pelletize,the result shows the quality of the combination with hunan ore,Chile ore and Iranian ore is better than others,its drop strength and roasted strength reach 4.3-5.1 and2860-4111 N.The quality of the combination with both Jiangxi ore and Iranian ore is very poor;(4)when four iron ore concentrate was used to pelletize,the quality of pellet changes a little with the different ore ratio,and the pellet's quality is better,its strength ranges from 3.6-4.2 and 3200 N.Finally,with the increase of the king of blended iron concentrate,it can gradually reduce the quality of different mixed ore pellet which could be influenced by the quality of the single iron concentrate.In addition,the experiments of different kinds and proportion of bentonite showed that:(1)the influences of two kinds of Bentonite on green ball strength and baking were the same.With the increase of the addition amount of bentonite,the dropstrength of green pellet gradually increased,the compressive strength of green ball increased first and then decreased,and it was the highest at 2.0%,shock temperature gradually increased,compressive strength after roasting increased first and then decreased,when the ratio of bentonite was 3.0%,it reached the highest;(2)Under the condition of the same ratio of bentonite,the drop strength,shock temperature and compressive strength after roasting of the pellets which added Changde bentonite is better than the quality of the pellets with Huajia bentonite,but the compressive strength of green pellets with Changde bentonite is lower than the pellet with Huajia bentonite,the ratio of the bentonite should be 2.0 %.Through the experiment with additive,the conclusion is that when the R is in the0.3-0.64,the pellets' quality is the best,the drop strength and roasted stremgth are more than 3 and 4600 N,the pellets' quality will decreased when alkalinity is less than or more than the scope,when the content of S is at 0.25 %,the quality of green ball and the compressive strength of the pellets after roasting is best.