Effects of pyrolysis upgrading temperature on semi-coke explosibility for blast furnace injection

The purpose of this work is to understand the semi-coke explosion issues and to improve the safety in semi-coke injection. It shows that the higher pyrolysis upgrading temperature is, the lower explosibility of semi-coke powder has. The effects of pore structure and functional groups on explosive properties are evaluated in detail. The surface area is determined to be at least as important as the volatile matter while the volatile matter content is more than 40.7%. The impact of surface area on explosibility is relatively small while the volatile matter content is less than 31.7%. The explosibility of the sample will show a correlation with combustibility when the comprehensive combustion index is in the range of 7.63 x 10(-14)-8.62 x 10(-14). Content of the oxygen-containing functional groups or the carboxyl and ether bond can all reflect the semi-coke/raw coal explosibility accurately to some degree, and the relative content of carboxyl and ether bond is more closely related to the length of return fire.