工业配煤焦炭中复杂微结构、组分及其化学状态分析

Microcrystalline structure of a commercial coke prepared from a mixture of different coals

用XRD、HRTEM、XPS以及SEM/EDS等手段对配合煤大生产焦炭进行表征和分析,研究了焦炭基质中碳质微晶结构、碳与氧等元素的结合形态,以及矿物质在焦炭基体中的存在形态,揭示了焦炭的本征结构。结果表明,焦炭中碳质结构是由结构规整的类石墨微晶和形状结构不规则的无定形炭构成,其中类石墨层片大小约为4 nm,堆叠厚度约为1.9 nm,且空间排列较为有序。碳与氧的结合形式主要是碳氧单键,其次是羧基和羰基,碳氧键合对焦炭中的类石墨微晶结构有一定的破坏,从而对焦炭的反应性(CRI)、反应后强度特性(CSR)产生影响。焦炭中的灰分主要有SiO2和"Al-Si-金属元素"两种矿物形式存在,且复合氧化物熔点较低,在焦炭基质中呈现球状形态。

The microcrystalline structure,the chemical states of oxygen and the ash components of an industrial coke prepared from a mixture of different coals were investigated by XRD,HRTEM,XPS and SEM/EDS to reveal the microstructure of the coke.Results show ed that the carbon matrix in the coke was composed of graphite microcrystallites and amorphous carbon.The graphite microcrystallites had an average lamellar size of 4 nm and stack thickness of 1.9 nm,and had a high orientation degree with in an optical domain.The oxygen in the coke was mainly in C-O,COOH and ■groups.The presence of oxygen distorted the graphite microcrystallites,w hich increased the coke reactivity with CO2and decreased its strength after the reaction.The ash components in the coke were SiO2and Al-Si-metal alloy,with the latter having a spherical morphology due to its low melting point.