Lump Coals Cracking in COREX Melter Gasifier

Lump coals were used in COREX process as the mainly fuel,but it was still necessary to feed a certain amount of coke to support burden and maintain adequate char bed permeability in melter gasifier.Tuyere coke samples were obtained by means of tuyere probing technology.Then,particle size analysis,microstructure analysis,permeability analysis and determination of the hot performance of tuyere coke were undertaken to investigate coke degradation and behavior of lump coals.Results show that larger particles(10 mm) of tuyere coke samples are mostly from charged coke deterioration and the smaller ones(10 mm) are mostly from lump coal pyrolysis.Moreover,reducing gases produced by lump coal combustion are considered to promote solution loss reaction leading to coke degradation.The physical and high temperature properties of char are inferior to that of charged cokes.The mainly parameter influencing char bed permeability is the char deterioration.Finally,combined with the former results,several measures are proposed to decrease the energy consumption of COREX process.