| Iron and steel industry as the foundation of the national economy in our country,has made a huge contribution for the construction of socialist modernization.However,the rapid development of it also brings a series of resources and environment problems,the high energy consumption,high emissions of greenhouse gases and intensive industry have become the main factors that restrict China's iron and steel industry development,and its great significance to energy conservation and emissions reduction.Coke as the main raw material of blast furnace ironmaking,it plays a very important role the blast furnace anterograde,to apply high reactive iron coke in the blast furnace ironmaking can significantly improve the efficiency of the blast furnace,reducing coke rate and reduce CO2 emissions.So further study of the influence mechanism of iron ore powder to raw coal pyrolysis and coking process,for the preparation of high reactive iron coke is of important guiding significance.In this paper,using the self-made thermal gravimetric analyzer,we have carried out a thermogravimetric analysis experiment on 4 kinds of coking coal with different proportion of iron ore,and the quality of coal sample has increased to 2 g,we studied the effects of iron ore fines ratio,heating rate,bulk density and sample size on the pyrolysis process of iron containing coal sample;the amount of CO,CH4,CO2 and H2 in pyrolysis gases were quantitatively analyzed by gas chromatograph.;Finally through 2 kg small coke oven making iron coke,we studied the effect of iron powder ratio on the porosity,micro strength,structural strength,optical microstructure and the distribution of iron powder of iron coke.The experimental results show that the degree of coalification is an important factor affecting the pyrolysis of coal,with coal metamorphism degree deepening,the coking coal pyrolysis in the final temperature of 900?conversion rate decreases,the maximum weight loss rate decreased gradually,corresponding to the maximum weight loss rate of temperature shift to high temperature;With the increase of the ratio of iron ore powder,4 coking coal in the pyrolysis temperature of 900?,the conversion rate increases,the maximum weight loss rate increases,the temperature corresponding to the maximum weight loss rate remained relatively unchanged,the apparent activation energy decreases gradually,it shows that iron ore powder can reduce the activation energy of coal pyrolysis and has a positive catalytic effect on the pyrolysis of coal;when the iron ore mixture ratio is 8%,the appropriate increase of heating rate,decreasing coal particle size and increased bulk density could promote the catalytic effect of iron ore powder for coal pyrolysis;with coal metamorphism degree deepening,the escape of H2,CH4,CO and CO2 of the 4 kinds of coking coal in the pyrolysis process generally showed a decreasing trend;For single coal,with the increase of the ratio of iron ore powder,In the escape of gas,the amount of H2 and CO2 increased obviously,and the amount of CH4 increased slightly,and the amount of CO decreased;with the increase of the ratio of iron ore powder,the porosity of the iron coke from 1/3JM,FM,and JM first decreased and then rised,the porosity of the iron coke from QM gradually increased;with the increase of the ratio of iron ore powder,the microstrength and structural strength of QM,1/3JM and JM are decreased gradually,and the microstructural strength of FM gradually increases and the structural strength of FM first increased and then decline;with the increase of iron ore powder ratio,the optical organization of coke with the corresponding changes,for the iron coke of 1/3 JM,FM and JM,the isotropic organization,fine grain mosaic,coarse mosaic tissue content gradually increased,fibrous and flaky tissue gradually less,the optical anisotropy index(OTI)gradually decreased,and the ?ISO content of the isotropic tissue gradually increased.For the iron coke of QM,the change of the optical organization is not very obvious. |
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