大型电站煤粉炉自身固硫灰渣的微观晶相分析

研究了电站1 025 t/h煤粉炉燃用Ca/S(摩尔比)=2.02的神木煤自身固硫灰渣的晶相组成，XRD分析表明,入炉煤中无定形的非晶相质量分数高达91.2%，CaCO3晶相质量分数为2.1%。满负荷下飞灰中因高温熔融形成的玻璃态非晶相质量分数高达70.5%，煤灰自身固硫产物CaSO4质量分数为3.4%，CaCO3和CaO质量分数为6.9%，使其仍具有进一步固硫的能力。满负荷下炉底渣中钠长石质量分数高达59.2%，非晶相质量分数为25.7%，未发现CaSO4、CaCO3或CaO晶相。当锅炉负荷降低时，飞灰中非晶相质量分数相应降低，炉底渣中非晶相质量分数升高。

Crystal compositions of self-desulfurization residues from a pulverized coal fired boiler

The crystal compositions of self-desulfurization residues produced in a 1 025 t/h pulverized coal fired boiler using Shenmu coal were studied, which had the self-desulfurization efficiencies of 27%～33% at the full steam load. It is found by XRD analysis that the amorphous phase content is 91.2% and the CaCO3 content is 2.1% in the feed coal. In the fly ash derived from coal combustion at the full steam load, the vitreous phase content is 70.5% and the sulfation product CaSO4 content is 3.4%, while the CaCO3 and CaO contents are 4.7% and 2.2%, respectively. In the bottom ash, the albite content is 59.2% and the vitreous phase content is 25.7%, but none of CaSO4, CaCO3 and CaO phase is detected. With a decreaseof steam load of the boiler, the vitreous phase content in fly ash decreases but that in bottom ash increases.