Study Of New Method Of Coal Blending For Coking Based On Non-ptrographic Active/Inert Components Separation

Many coking coals were used in this study. Heavy component, loose medium component and dense medium component of coals were gained by extraction and stripping, which realizes separation of non-ptrographic active/inert components. FT-IR and caking index tests of coals and their group components and coking test were carried out. Coke quality was characterized by swelling ratio, coking ratio, index of microscopical strength, reactivity of particulate coke and coke strength after reaction. Mechanism between coal caking property and non-ptrographic active/inert components was studied by multiple linear regression analysis. Peak separation and quantitative calculation of FT-IR spectra were performed and relationship between caking property and typical functional groups of coal was investigated. Prediction model of coke quality combined with BP neural network based on non-ptrographic active/inert components was built. The results are as follows:Separation of the non-ptrographic active/inert components can be realized by extraction and stripping. The loose medium and the dense medium components are the non-ptrographic active component and the heavy component is on the contray.The dense medium and the loose medium components are the two key factors to determine the caking property of raw coals, and they are the source materials of fluidity and swelling of coal, respectively; the heavy component without the swelling and fluidity was cohered by the other components. The loose medium, the dense medium and the heavy components are swelling matter, fluidity matter and inert matter during coal caking process, respectively. And the effect of them in order of quality of swelling matter > content of swelling matter > quality of inert matter > content of fluidity matter > quality of fluidity matter > content of inert matter.As to improving coal caking property, content and quality of fluidity matter are not the bigger the better, and content of inert matter is not the less the better. When quality of fluidity matter is under appropriate condition, content of swelling matter, quality of swelling matter and quality of inert matter are the bigger the better. Among swelling matter, fluidity matter and inert matter, there is a suitable scale which is the key of good coal caking property.There is a close relationship between caking property and FT-IR spectra of coal, especially in the regions of 3000-2800 and 3700-3000 cm-1. In the range of coking coal, the aliphatic chain length or branching degree of aliphatic structure compared with other functional groups is a primary even critical factor of caking property.The caking property is codetermined by major factor(aliphatic structure) and secondary factor(hydrogen bond) and there is a synergic relationship between aliphatic structure and hydrogen bond(including-OH or-NH).The most dominant sort of binding force in coal is hydrogen bond. An associative structure even supermolecular structure is formed when a number of hydrogen bonds associated together. During the state of metaplast, such structures is broken and changes into plastic mass which need a considerable amount of energy. During coal pyrolysis, this kind of bonding structure compared with aliphatic group is not the main source of metaplast.New method of cokemaking and coal blending based on separation of non-ptrographic active/inert components is proposed.