Several typical ash samples from a 0.25 MW test furnace fired black liquor coal slurry were selected for investigation. The phases and compounds containing sodium in ash samples were acquired from X-ray diffraction an...Several typical ash samples from a 0.25 MW test furnace fired black liquor coal slurry were selected for investigation. The phases and compounds containing sodium in ash samples were acquired from X-ray diffraction analyses. As well, detailed analyses of the amounts of major mineral elements along thickness gradients of representative ash samples were carried out. The elements, including Na, Si, A1, S and C1 were analyzed by the advanced electron probe microanalyzer equipment, which provid evidence and interpretation for the analytical results of XRD. The findings indicate that the occurrence form of sodium has experi- enced important changes during the combustion of black liquor coal slurry, which translated into nepheline, thenardite, sodium sulfate, sodium chloride, sodium silicoaluminate, hanyne and other phases containing sodium, from NaOH, Na2CO3 and Na2S in raw fuel. Of all the sodium compounds, nepheline, thenardite and sodium sulfate are the most important forms of Na in solid com- bustion residues. Such a transformation of Na during the combustion of black liquor coal slurry resulted in a considerable impact on ash deposition and is not only different from the raw coal and papermaldng black liquors, but is also affected by local circum- stances in the combustion furnace. Amounts of Na, S and C1 in ash deposits from low temperature zones were larger than those from high temperature zones. Our findings should provide important theoretical instructions for industrial applications of black liquor coal slurry.展开更多
Two coal samples of similar rank were chosen from Australia and China to investigate the differences in Coal-Water Slurry （CWS） made from them. The effect of ash content and particle size gradation on these properti...Two coal samples of similar rank were chosen from Australia and China to investigate the differences in Coal-Water Slurry （CWS） made from them. The effect of ash content and particle size gradation on these properties was also studied. Different grinding times were used when grinding the two coals and particle size analysis of these ground coals was used to select samples with a ＂double-peak＂ particle size distri- bution. All the ＂double-peak＂ samples were used to prepare a CWS. The concentration, viscosity, fluidity, and stability of each CWS were measured. The results show that the properties ofa CWS prepared from a coal sample with a ＂double-peak＂ size distribution are better than those CWS prepared from samples with a mono-modal particle distribution. The ash content of Australian coal is 21.72g higher than the ash content of Shenhua coal. The highest coal concentration in slurry from the Australia coal is 11.01% higher than in CWS from the Shenhua coat. The fluidity and stability of the CWS prepared from the Australian coal are both better than the fluidity and stability of slurry prepared from Shenhua coal. High ash content in the Australian coal imnroves the nulning results of a CWS made from it.展开更多
基金Projects 2004CB217701 supported by the National Basic Research Program of China 2005-1 by the Scientific Research Foundation of the Ministry ofEducation of Hebei Province
文摘Several typical ash samples from a 0.25 MW test furnace fired black liquor coal slurry were selected for investigation. The phases and compounds containing sodium in ash samples were acquired from X-ray diffraction analyses. As well, detailed analyses of the amounts of major mineral elements along thickness gradients of representative ash samples were carried out. The elements, including Na, Si, A1, S and C1 were analyzed by the advanced electron probe microanalyzer equipment, which provid evidence and interpretation for the analytical results of XRD. The findings indicate that the occurrence form of sodium has experi- enced important changes during the combustion of black liquor coal slurry, which translated into nepheline, thenardite, sodium sulfate, sodium chloride, sodium silicoaluminate, hanyne and other phases containing sodium, from NaOH, Na2CO3 and Na2S in raw fuel. Of all the sodium compounds, nepheline, thenardite and sodium sulfate are the most important forms of Na in solid com- bustion residues. Such a transformation of Na during the combustion of black liquor coal slurry resulted in a considerable impact on ash deposition and is not only different from the raw coal and papermaldng black liquors, but is also affected by local circum- stances in the combustion furnace. Amounts of Na, S and C1 in ash deposits from low temperature zones were larger than those from high temperature zones. Our findings should provide important theoretical instructions for industrial applications of black liquor coal slurry.
基金received funding from the Australian Government as part of the Asia-Pacific Partnership on Clean Development and Climate
文摘Two coal samples of similar rank were chosen from Australia and China to investigate the differences in Coal-Water Slurry （CWS） made from them. The effect of ash content and particle size gradation on these properties was also studied. Different grinding times were used when grinding the two coals and particle size analysis of these ground coals was used to select samples with a ＂double-peak＂ particle size distri- bution. All the ＂double-peak＂ samples were used to prepare a CWS. The concentration, viscosity, fluidity, and stability of each CWS were measured. The results show that the properties ofa CWS prepared from a coal sample with a ＂double-peak＂ size distribution are better than those CWS prepared from samples with a mono-modal particle distribution. The ash content of Australian coal is 21.72g higher than the ash content of Shenhua coal. The highest coal concentration in slurry from the Australia coal is 11.01% higher than in CWS from the Shenhua coat. The fluidity and stability of the CWS prepared from the Australian coal are both better than the fluidity and stability of slurry prepared from Shenhua coal. High ash content in the Australian coal imnroves the nulning results of a CWS made from it.
