煤微波脱硫介电性质变化及其影响因素

Analysis of influence factors of dielectric properties change with coal desulfurization by microwave radiation

为明确高硫煤微波脱硫前后介电性质变化及影响因素,选用微波频率2.45 GHz与HAc-H2O2协同法进行了脱硫试验,并采用XRD与XPS对试验前后煤样的成分进行了分析表征,根据表征出的成分筛选出相应模型物,利用传输反射法测定了煤样及筛选模型物在0.5~18 GHz频率范围的介电常数。试验结果表明：试验前后煤的介电性质在9~12 GHz和13~18 GHz频率范围内存在较明显差异,试验后煤样的复介电常数实部和虚部出现了不同程度地降低;煤和筛选模型物的复介电常数测定反映矿物组分在13~18 GHz范围对煤样介电性质影响较明显,以固态小分子硫醇硫醚、硫砜及噻吩类化合物为代表的有机硫组分则集中在9~12 GHz对煤样介电性质有影响,但程度相对较弱;筛选的有机硫模型化合物与微波耦合能力为：（亚）砜〉硫醇硫醚〉噻吩,与利用material studio软件计算出的分子偶极矩大小变化一致,符合分子偶极矩越大对微波响应越强的一般规律。

In order to clarify the influencing factors of dielectric properties change with coal high sulphur desulfurization by microwave radiation,the collaborative method of 2. 45 GHz microwave and HAc- H2O2 for coal desulfurization was chosen,the sample components was analyzed and characterized by XRD and XPS,the corresponding model compounds was selected according to the results of the composition analysis,the permittivity of coal and model compounds were measured in 0. 5- 18 GHz range of frequency,The results showed that： he dielectric properties of coal had obvious differences in 9- 12 GHz and 13- 18 GHz frequency before and after the experiment,the dielectric loss is reduced in both frequency bands,the permittivity measuring reflected that pyrite and other mineral components had obviously affect on dielectric properties of coal in the 13- 18 GHz,and organic sulfur compounds represented by small solid molecules of thiol,sulfide,sulfoxide,sulfone and thiophene had weaker affect on dielectric properties of coal in the 9- 12 GHz,the coupling capabilities of the organic sulfur model compounds to microwave were sulfone（ sulfoxide） thiol（ sulfide） thiophene,the magnitude changes of molecular dipole moment calculated by the software named material studio were the same,this complied with that the greater the dipole moment was,the stronger the responses to microwave.