| Content of trace elements in coal could be showed correctly that this is according to evaluate the environmental effects on trace elements which is harmful for potentially.And also,this is difficult to reseach in the field of coal science. environmental around the world at present.The thesis was supported by horizontal research projects《the Classification and the Limits of arsenic and mercury in standars about coal》and the national science and technology support projects《Steam coal blending and Quality demonstration project》from Beijing Research Institute of Coal Chemistry which is a part of China Coal Research Institute that study on the law of migration and the limits of arsenic,mercury and in coal.In this paper,the methods of instrumental analysis on arsenic, mercury and chlorine in Coals could be innovated and overcomed.The methods of instrumental analysis on arsenic and mercury by atomic fluorescence spectrometry were not reported as yet.Many dissolution methods and the leaching results of arsenic and mercury in the coal samples from different regions were contrasted.And the analysis which could be applied in practice mostly have be made out that the methods of instrumental analysis are feasible.By studying the extraction sequence innovatively, this experiment aimed at the speciation analysis that could be vulnerable to the polarity of extracting agent and the proper order of extraction seriously, especially in this experiment,the influence of extraction sequence on sulfide formation and organic formation in obvious,and the leaching rate respectively reaches maximum value in difference extraction sequence.The study coulde provided for a serious train of thought and consider the Analytical Chemists who study the speciation analysis.Through large amount of lab experiments,a simplified, rapid and costless turbidimetry for the determination of low-chlorine content in coal has been developed.By comparison with experimental data that is tested for combustion hydrolysis-potentiometric titration provided by Sichuan Province the sources of coal quality monitoring,the error is content with the uncertainty of 0.003 % that is satisfied for analysis on the trace amounts of low-chlorine in coal. In addition,the forms of chlorine with potassium,sodium,calcium and magnesium has been discussed by analysis of regression which is novel for visual.The results shows that their relationship are not close as according to reports in the literature differently.In this experiments, the distribution of arsenic and mercury in volatility were probed into,and the results show that arsenic and mercury are all volatile elements, but mercury is be more volatily than arsenic.When the mercury volatiled completely at the low temperature of 500℃,arsenic volatiled completely at the temperature of 1200℃. The factors affecting the volatilization of mercury were in the order:the combustion temperature≥burning time>coal particle size>the flow of air≈sample weight;The factors affecting the volatilization of arsenic were in the order:the buring temperature>sample weight>burning time>the flow of air≈particle size. In order to study arsenic and mercury better in combustion experiments,the optimum combustion conditions could be defined,such as sampling weight was 1.0000 g, burning time 1h,buring temperature 1000℃, absorbtion dielectic 5% aqua regia.The testing apparatus were improved better, you will feel old nitrogen-oxygen of complexity and new electromagnetic air pump of small size, portability, use with facility and steady coming in to replace them.In addition, the testing apparatus is very easy to popularize for its low cost, simplicity and facility.
|
PDF Full Text Request