Study On Gasification Reactivity And Ash Fusion Properties Of Ningdong Non-caking Coal

The stability of coal quality and the ash fusion properties are the key factors whichrestricted the long-term and stable operation of coal gasifier all the time. In this paper, the rawmaterials were Yangchangwan slack and clean coal, Meihuajing slack and clean coal, andJinfeng slack coal from Ningdong. The effect of coal blending ratio and additives on blendingcoal quality and ash fusion properties was studied by a coal blending method. The main factorsinfluencing gasification reactivity and ash fusion properties of the blending coal were analysed,and a prediction model of ash fusion properties was established.(1) The gasification reactivity of Ningdong non-caking coal was studied on a fixed bedreactor, using CO2as the gasification agent. The results show that the gasification reactivity ofNingdong non-caking coal was low. There are little difference in the gasification reactivity ofYangchangwan slack and clean coal, Meihuajing slack and clean coal and Jinfeng slack coal,and the gasification reactivity are all in the range of70%and75%, which attribute to theexistence of microporous pore in Ningdong coal char, the little influence of minerals on thegasification reactivity, as well as the low ash fusion temperature.(2) The influence of blending ratio on coal quality of blending coal was studied. Theresults show that Ningdong blending coal satisfied a linear relationship between its proximateanalysis and ratio, and the correlation coefficient R2for linear equation of proximate analysisof blending coal (Yangchanwan slack coal and Meihuajing clean coal ratio at5:5or7:3) isgreater than0.95. ash content of the blending coal can meet the requirements of GSP gasifier.Gasification reactivity of Ningdong blending coal change in the range of70%~75%.(3) Ash fusion properties of Ningdong non-caking coal was studied by pyramid methodunder the weak reductive atmosphere. The results show that FT increased gradually in theorder of Meihuajing clean coal, Yangchangwan slack coal, Meihuajing slack coal,Yangchangwan clean coal, and Jinfeng slack coal. Their FT are1120℃,1152℃,1204℃,1217℃, and1222℃, respectively. (4) The influence of added additives on ash fusion properties of Ningdong non-cakingcoal was studied. The results show that addition of CaO, Al2O3in ash and addition of kaolin,limestone in coal can increase ash fusion temperature. FTs are higher than1200℃when theadditions amount of CaO, Al2O3in ash and addition of kaolin, limestone in coal are35%,10%,3%and15%respectively, and FTs are higher than1300℃when their additionsamount are40%,30%,10%and17%respectively.(5) The influence of blending ratio on ash fusion properties of blending coal was studied.The results show that there is a linear relationship between ash fusion temperature andblending ratio in blending coal which blended by Yangchangwan slack coal and Meihuajingclean coal, FT of the blending coal is between1130℃and1220℃. Ash fusion properties ofNingdong non-caking coal can not be adjusted significantly through simple blending coal.(6) Ash fusion properties of Ningdong non-caking coal prediction model was established.The results show that S(SiO2value) has a best correlation with ST, HT and FT of Ningdongcoal ash. Prediction model is as follow:ST=1931x2-2133x+1683, HT=2006x2-2214x+1714, FT=2077x2-2289x+1745(x=S)；B/A has a best correlation with DT. Prediction model is as follow:DT=118.8y2-239.5y+1179(y=B/A)...