Experiment Research And Analysis Of Mechanism Study On Shell Powder As Coal Briquette Desufurzier

China is the world's largest coal producer and consumer country. And 90% of SO2 emissions comes from coal combustion. Coal briquette is a kind of combustion to reduce ash, and it is used widely in China. Usually, dolomite and limestone are used as coal briquette desulfurizer. But the desulphurization rate is greatly reduced because of the thermal decomposition and high-temperature sintering of calcium sulfate. In this thesis, shell powder was researched to increase the desulphurization rate, and the mechanism of sulfur fixation was discussed.Orthogonal method which the combustion temperature, the size of coal particle and shell powder and the ratio of Ca/S(molar ratio) four most important factors were chosen which have great influences on the desulphurization rate was used to investigate the characteristic of sulfur capture of shell powder. The results showed that the combustion temperature had greatest impact on the desulphurization rate. And the comparative experiments with calcium carbonate indicated that the shell powder had higher desulphurization rate at high temperature(1150℃).The additive which was selected from the analysis of the part of elements of shell powder effect of 6 kinds of different single-composition was investigated at 1150℃. The results showed that each additives except iron oxide produced different promoting effect on shell powder residue sulfur capture and the promoting effect and mechanism were dissimilar. In order to further discuss the desulphurization rate of shell powder at 1150℃and based on the single-composition experiment,15 kinds double-composition additives were studied. It was found that most of double-composition additives improved the desulphurization rate significantly. For example, the desulphurization rate of SiO2-MgO is 72.07% and Al2O3-MgO is 75.19%. According to the results of experiments of double-composition, three compositions additive of SiO2-Al2O3-MgO was researched. The shell powder and calcium carbonate were used as two kinds of desulfurizer in the three compositions additive experiments. The results showed that the desulphurization rate has been further improved. When the adding amount of SiO2-Al2O3-MgO is 0.05g-0.05g-0.1g, the desulphurization rate of the shell powder is 86.66% and calcium carbonate is 76.99%.The cinder of coal and the cinder of coal simples which were added calcium carbonate, calcium carbonate and SiO2-Al2O3-MgO, shell powder, shell powder and SiO2-Al2O3-MgO were analyzed by the X-ray diffraction(XRD), LV scanning electron microscopy (SEM) and Energy dispersive spectrometer(EDS). The results indicated that the cinder of briquette which was .added shell powder and SiO2-Al2O3-MgO contained a lot of sulfur compounds and high-temperature decomposition compounds. The cinder particle was closely of quality of material, and it surface was smooth. Sulfur compounds were wrapped in cinder particle because of the melting produced by shell powder and SiO2-Al2O3-MgO. Then the desulphurization rate was increased.