CFB锅炉粉煤灰工艺矿物学特性

Mineralogical characteristics of CFB boiler fly ash process

粉煤灰一般用于水泥及各种建材制备,CFB锅炉燃料适应性广,掺烧各种劣质燃料后造成粉煤灰中碳含量较高,探明CFB锅炉粉煤灰工艺矿物学特性是其综合利用的基础。以某大型石化公司1号、2号、4号CFB锅炉粉煤灰为例,研究其工艺矿物学特性。结果表明,3种粉煤灰粒度较细,<0.074 mm粒级均>90%,烧失量均超过11%,不利于建材化利用。随着密度级增加,烧失量逐渐降低。XRF分析表明粉煤灰主要元素为Al_(2)O_(3)、SiO_(2)、SO_(3)、CaO和Fe_(2)O_(3),总质量分数超过80%,同时夹杂少量Na_(2)O、MgO、K_(2)O等。XRD分析表明粉煤灰主要组分为CaO、CaSO_(4)和SiO_(2)。SEM-EDS、XPS和EMPA分析显示粉煤灰以无定形颗粒为主,球形颗粒较少,颗粒表面主要元素为C、O、Ca、S、Si和Al。3种粉煤灰吸脱附曲线形状一致,1号、2号粉煤灰比表面积相近,孔隙以中微孔为主,4号粉煤灰比表面积达20.9159 m^(2)/g,平均孔径为6.9539 nm。深入分析3种粉煤灰工艺矿物学特性为其资源化综合利用提供了数据支撑。

Fly ash is generally used for cement and various building materials preparation.CFB boiler fuel is widely adaptable,the carbon content in fly ash is high after mixing and burning various kinds of poor-quality fuels,and exploring the mineralogical properties of fly ash process is the basis of its comprehensive utilization.The process mineralogical properties of the fly ash from the No.1,No.2 and No.4 CFB boilers of Maoming Petrochemical were analyzed in depth as examples.The analysis results show that the particle size of the three types of fly ash is fine,-0.074 mm particle size is above 90%,and the burn loss is more than 10%,which is not conducive to the utilization of building materials.With the increase of density level,the burn loss gradually decreases.The main components of fly ash are Al_(2)O_(3),SiO_(2),SO_(3),CaO and Fe_(2)O_(3),with the total content over 80%,and a small amount of Na_(2)O,MgO,K_(2)O,etc.are also interspersed.XRD analysis show that the main mineral composition of fly ash was CaO,CaSO_(4)and SiO_(2).SEM-EDS,XPS and EMPA analysis show that amorphous particles of fly ash are predominant,with fewer spherical particles,and the main elements on the surface of the particles are C,O,Ca,S,Si and Al.The shapes of the adsorption and desorption curves of the three types of fly ash are consistent,the specific surface areas of No.1 and No.2 fly ash are similar,the pores are mainly medium micropores,and the specific surface area of No.4 fly ash reaches 20.9159 m^(2)/g with an average pore size of 6.9539 nm.Through in-depth analysis of the mineralogical properties of the three types of fly ash processes,data support is provided for their resourceful and comprehensive utilization.