Study On Strengthening Of Pulverized Coal Injection And Characters Of Coal In Blast Furnace Of Xin Lingang I&S Co.

Because of the shortage of coke resources,increase the PCI has already become the main measure to reduce the ironmaking cost.However,the study on coal performance was the primary factor which decided coal injection rate.At present,a feasible method is to research the performance of all the rich coal sources in order to further enhances coal injection rate.In this paper,some fundamental work on physicochemical of Xin Linfen's coal has been carried out,including the assay of the grindability of coal and reaction characteristics of CO₂,the assay of coal's industrial, elemental,emanated heat and combustion characteristics in different condition. According to the need of PCI rate in the blast furnace at Xin Lingang,included in the study were the employment of the method of theoretical analysis and experimental research with practical production to find out the measure of increasing PCI into BF at Xin Lingang.The results show that the following measures should be taken to achieve high coal ratio in Xin Lingang blast furnace:Firstly,the hard grove grindability of anthracite and bitumite is at 80 and 50 apart. Bitumite will suck water when these coal were grinded into small particles.On the premise of guaranteeing the safe,we can enhance air temperature and air volume which get into the coal mill.Due to higher activity of coal and CO₂,to raise bitumite's ratio is favorable to reduce the reaction of coke with CO₂ and enhance coal's strength in high temperature environment.Secondly,ash of Xin Lingang's coals is great differencet,and the anthracite ash is excessively high to 14%.Meanwhile three kind of bituminous coal's volatility content are higher,so increasing the ratio is favor to improve the pulverized coal injection.The low emanated heat leads to the low replacement ratio.It's most important problem that abases ash of coal powerful should be solved at first.Thirdly,the test results show that the proportion of-200 coal's granularity should be controlled around the 70%,the proportion from 30%to 70%which will make coal combustion rate to enhance approximately 12.8%,and the oxygen enrichment rate can be increased to 2-3%.Under the test condition,rich oxygen rate increases 1%that makes the coal combustion rate increased about 2.2%.Last but not least,the combustion rate of bitumite is higer but anthracite lower at Xin Lingang,so the proportion of bitumite should be increased.The research suggested that the bituminite should be 50⁶0%under the condition of economic technology at present.Based on the theoretical study and experimental analysis,the PCI has been increased effectively in Xin Lingang.through applying these research results in the iron making practice.The PCI of BF have been approached to 141kg/t·Fe,and great economic profits have been obtained.