Physical and Chemical Characteristics of Coal-binder Interface and Carbon Microstructure near Interface

Abstract

In this study, investigations were made to understand the mechanism of increase in coke strength on binder addition by analyzing physical and chemical characteristics of coal-binder interface. Three binders, oil derived Asphalt pitch (ASP), coal derived HyperCoal (HPC) and Coal tar pitch (CTP) were used to understand the effect of binder. A new method to observe the coal-binder interface boundary at microscopic level by Scanning Electron Microscope (SEM) was developed. When base coal was a non-caking coal, coal-binder interface boundary was clearly observed by SEM for the first time. From observed images, it was found that ASP and HPC bound differently on the coal surface. When base coal is a caking coal, the interface could not be distinguished but sulfur mapping confirmed the presence of interface. Preliminary Laser Raman analysis suggests there may be some interactive effect of coal and binder on each other's carbon structure development. Contribution of fraction of coal surface coated with binder towards coke strength is considered.

Analysis of metamorphism and tendency of black coals to spontaneous combustion

“…Similar results ( Fig. 3) are obtained by processing other experimental data [19][20][21][22][23][24][25][26]. This indicates a different transformative effect of pressure, temperature, and time factors at individual stages of metamorphism.…”

“…1, c). TECHNOLOGY [19][20][21][22][23][24][25][26]: а -the ratio between the carbon content and a mixture of other components (О 0 , Н 0 , N 0 ); b -the ratio between the content of carbon and oxygen; c -the ratio between the content of carbon and hydrogen; d -the ratio between the carbon content and nitrogen; I, II, III, IV -ranges of changes in the properties of coal; 1 -linear interpolation of experimental data; 2 -the boundaries of the change in components; • -experimental data…”

“…The interdependence of the content of hydrogen (H 0 ) and oxygen (O 0 ) in the organic (combustible) mass of coal according to[19][20][21][22][23][24][25][26] : 1 -the boundaries of the change in the considered parameters; • -experimental data…”

Effect of Carbonization Heating Rate on the Tensile Strength of Cokes Prepared from Chemically Upgraded Low Rank Coals

“…and Solvent Recovery Method Figure 5 shows SEM image of polished fractured surface of upgraded coke L-UG-THF-pellet40MPa-1000-3-10 (L-UG = Upgraded coal; THF = solvent used for recovery; pellet40MPa = compaction pressure; 1000 = maximum coking temperature; 3 = heating rate in second zone; 10 = heating rate in third zone). 5,14,15,18) It can be seen that solid insoluble coal particles were embedded in a matrix of binder. 5,14,17,26,29) This suggests that on heating, binder which has excellent thermoplastic properties, gets melted and coated on the coal particles.…”

“…5,14,15,18) It can be seen that solid insoluble coal particles were embedded in a matrix of binder. 5,14,17,26,29) This suggests that on heating, binder which has excellent thermoplastic properties, gets melted and coated on the coal particles. It also filled the space between the particles.…”