Study On The Fractionated Thermal Dissolution Of Shenfu Coals And The Application Of Extracts And Residues In The Coal Blending For Coke-making

In this thesis the thermal dissolution(TD)of Shenfu(SF)coal were investigated in different solvents at 320~380?.FTIR,TG,G,ultimate analysis,and dynamic viscoelastic measurement were used to characterize the structure and properties of the extracts and residues.The extracts and residues were blended into coking coal to study its effect on the quality of coke.The results suggested that the solvent and temperature are very important factors for TD yield.The TD yield increased first and then fall with the temperature rise and the TD yield increased as the polarity of solvent increasing.When 1-MN was used as a solvent,the maximum TD yield was obtained at 360? as 44.6%.At 360?conditions,the TD yield in 1-MN+10%MT was the highest.Addition of 10%methanol in 1-MN can promote greatly the TD yield.FTIR analyses showed that the contents of oxygen-containing functional groups and the heavy components with poly aromatic structure in the TD soluble fractions increased as the polarity of solvent increasing.Similar tendency was found with the TD temperature rising,which is also consistent with the results of ultimate analysis.The ultimate analysis results showed that the low rank SF coal can be modified into higher rank coal by TD.The measurement of dynamic viscoelasticity results showed that the softening temperature of 1-MN+10%MT obtained at 380? was the highest.With the increase of polarity of the solvent,the softening temperature of TD soluble fractions obtained increased.The temperature range of thermoplasticity of 1-MN TD soluble fractions obtained at 360? was the widest.With the decrease of polarity of solvent,more aliphatic hydrocarbons with better caking properties and suited molecular weight distribution can be thermally dissolved becoming into TD soluble fractions.The coking properties of addition of different extracts in coal blends were investigated.The result showed that compared with the coke from the standard coal blends,the quality of coke was improved obviously after adding TD soluble fractions into the coal blends.The quality of coke fall first and then increased with the TD temperature of the added TD soluble fraction rise.The quality of coke of the TD soluble fractions obtained in 1-MN at 340? was the best and it became worse as the TD soluble fraction obtained from the increased polarity of solvent.Addition of the heavy TD soluble fraction and residues can also improve the quality of coke in some extents compared to that of SF raw coal.