Fundamental Study On Degradation Behavior Of Coke With H₂O And CO₂

The energy consumption of blast furnace production is primary among all the steel production system. Mineral fuel combustion and excessive emission of carbon containing gases are the focus of energy saving and emission reduction. However, it is impossible to reduce carbon emission substantially just by means of traditional ways,such as coal injection, burden and so on. In order to further reduce CO₂ emissions,new technology of injecting auxiliary fuel contained more hydrogen have been studied in recent years. But, the large use of rich hydrogen fuel leads to the result that the content of H₂ O increases obviously in blast furnace, H₂ O has important effect on the property of coke.In order to explore the degradation rules of coke with CO₂ and H₂ O, the degradation behavior of coke with CO₂ and H₂ O were studied by self-made gas-solid reacting apparatus from 950? to 1250? in this paper. The following results were obtained:?1?The starting solution loss temperature of coke with CO₂ and H₂ O are about826??789?. The strenuous solution loss temperature are about1289??1164?. The gasification rate of coke with H₂ O is about 1.27-3.16 times of that with CO₂ and difference of the gasification rate was narrowing with temperature rising. Solution loss rate increased by 1%, the strength after reaction of coke with CO₂ and H₂ O reduced by 1.200% and 0.786%separately.?2?The reaction process of coke with both of CO₂ and H₂ O are controlled by interfacial chemical reaction from 950 ?to 1200 ?. The both of the reaction rate of the two can be described by equation 1-?1-X?1/3=kt. The activation energies of coke with CO₂ and H₂ O are 165.48 kJ/mol?82.25 kJ/mol respectively.?3?The deep reaction of coke CO₂ and H₂ O were studied after coke weights loss30% by means of volume density. The amount of solution loss shows a decreasing trend from the exterior to the interior of coke particle. Compared with the reaction of coke with CO₂, the reaction depth with H₂ O is less. The difference of solution loss rate is greater between the exterior and the interior. Both of the size and amount of connected pore are less.?4? Compared with the reaction of coke with CO₂, the difference of the percentage of pore size less than 10?m is greater. The percentage content of anisotropic texture of coke with H₂ O was lower and the optical texture index OTI was less than that with. CO₂.