通过对煤粉进行酸洗脱矿重新负载,并在一维沉降炉上对K2O,Na2O,CaO,Fe2O3金属氧化物的负载煤粉进行再燃试验研究,最后对试验结果进行了分析和探讨。研究结果表明金属氧化物对用煤粉来再燃脱硝效果有重要影响。煤灰中金属氧化物含量越高,煤粉再燃脱硝效果越好。负载等质量金属氧化物的煤粉用来再燃脱硝的效果依次为:Na2O~Fe2O3〉K2O〉CaO;其中Na2O和CaO与再燃区气氛相关性较弱,而K2O与Fe2O3则随还原性气氛的增强,效果有显著提高,CaO负载过量后,反而有不利影响。研究成果可为今后选择有效的再燃用的煤粉添加剂奠定一定的理论基础。
The experimental research on reburning with ionloaded pulverized coal, deashed pulverized coal and original pulverized coal to reduce the NOx in the flue gas was conducted in a one-dimension-drop tube furnace. In the experiments, the ionloaded pulverized coal was prepared by using the acid to deash the original pulverized coal and then loading it with metal oxides, such as K2O, Na2O, CaO and Fe2O3. Based on the experimental results, some factors affecting the catalytic effect of the metal oxides in the reburning with ionloaded pulverized coal were analyzed and discussed. The experimental results show that metal oxide weightily affects the NO reduction in reburning with coal, and the NO reduction increases with the increase of the metal oxide concentration in pulverized coal. The NO reduction effects in reburning with pulverized coal ionloaded with different equiponderant metal oxides were compared, and it was found that their reduction effects are in following order: Na2O-Fe2O3〉K2O〉CaO. Experiments show that, during reburning with pulverized coal loaded with Na2O or CaO, the NO reduction isn't sensitive to the fume conditions, while when the pulverized coal loaded with K2O or Fe2O3 is used, the NO reduction increases obviously with the increase of the stoichiometric ratio. Our experimental research may lay the theoretical foundation of choosing the effective additive used for promoting the NO reduction via reburning with pulverized coal.