【作者】 刘博；

【导师】 周安宁；

【作者基本信息】 西安科技大学 ， 矿业工程， 2014， 博士

【摘要】 以煤炭自燃防治材料和新型无卤阻燃材料的制备及应用为背景，基于煤特殊的微纳米孔隙结构和官能团结构特征，借鉴锌镁铝层状双氢氧化物（Zn/Mg/Al-LDHs）的制备方法及影响因素研究，探讨了Zn/Mg/Al-LDHs/神府煤复合材料（CLCs）的制备方法、结构及性能。研究成果对新型矿物功能材料制备及应用具有重要的理论意义和应用价值。通过FTIR、XRD、GC-MS和低温氮气吸附等手段，系统研究了低温氧化对神府煤（SFC）腐植酸产率及其各级分腐植酸分布的影响，以及低温氧化、脱灰及脱腐植酸等预处理对SFC孔结构分布的影响。结果表明，氧化SFC的总腐植酸产率随着氧化温度的升高及氧化时间的延长而迅速增加。预处理SFC中的黑腐酸产率最高，其次为棕腐酸，黄腐酸产率最低。预处理SFC的中孔增加、比表面积减小。用共沉淀法制备了Zn/Mg/Al-LDHs。通过XRD、FTIR、SEM和TG-DSC分析研究了金属离子比例、阴离子（煤基腐植酸及其不同级分）种类、以及微波和超声强化方式等对Zn/Mg/Al-LDHs组成、结构和热性能等的影响。结果表明，腐植酸在水滑石层板表面的络合及吸附作用诱导Zn/Mg/Al-CO3-LDHs层板沿着腐植酸的表面弯曲生长，从而形成球形团簇状Zn/Mg/Al-HAs-LDHs复合材料。微波、超声辅助共沉淀法可提高Zn/Mg/Al-LDHs晶体颗粒的均匀性、使粒径减小、团聚降低。Zn/Mg/Al-LDHs的热稳定性与其中的金属元素的比例有关，镁离子增加时热稳定性降低，吸热分解温度范围变宽。采用原位共沉淀法方法合成了CLCs。CLCs的结晶度随SFC的质量分数的增加而降低。结果表明，改变煤低温氧化温度及LDHs的晶化时间，可对CLCs表面Zn/Mg/Al-LDHs的形貌进行调控，其调控机理为煤表面官能团对金属离子络合与孔道吸附之间耦合作用。采用TG-DSC热分析方法，系统研究LDHs-煤复配材料及CLCs的热性能，探讨CLCs的煤自燃防治性能。结果表明，当Zn2Al1-CO3-LDHs、 Mg2Al1-CO3-LDHs、Zn1Mg1Al1-CO3-LDHs以物理混合方式加入SFC，添加量分别为3%、5%和15%时，SFC自燃临界温度较高。当Zn1Mg2Al1-CO3-LDHs以纳米纤维状复合分散于SFC时，预防煤炭自燃效果最好，这主要归因于在煤炭自燃过程中，CLCs可形成致密的金属氧化物-碳（LDOs-C）阻隔层。Zn/Mg/Al-LDHs和CLCs预防煤炭自燃的机理为煤低温氧化放热过程与LDHs和CLCs吸热分解过程耦合作用。CLCs具有独特的自修复性能。用共混方法制备CLCs/EVA复合材料。用热释放速率、氧指数和UL94阻燃级别等指标评价了CLCs/EVA的阻燃特性。结果表明，CLCs具有高效抑烟的阻燃优势。CLCs/EVA复合材料的阻燃性能随CLCs的填充量的增加而增加，因此，LDHs和SFC之间具有协同阻燃效应。CLCs在CLCs/EVA复合材料中呈现增强增韧作用。更多还原

【Abstract】 Focus on the preparation and application of the prevention materials for the coalspontaneous combustion and the novel halogen-free flame retardant materials, the preparation,structure and properties of Zn/Mg/Al-LDHs/Shenfu coal composites (CLCs) were explored,according to the micro-nano pore structure and functional group characteristic of Shenfu coal(SFC) as well as the studies on the preparation and properties of Zn/Mg/Al layered doublehydroxides (Zn/Mg/Al-LDHs). The results are with significant theoretical meaning to thepreparation and application of the novel mineral functional nano-composites.Effect of low temperature oxidation of SFC on its humic acid (HA) yield and thedistribution of its different HA fractions (black humic acid (HAIII), brown humic acid (HAII)and fulvic acid (HAI)), and effect of pretreatments (low temperature oxidation, de-ashing aswell as removing HA) on the pore distribution of SFC were investigated by FTIR, XRD,GC-MS and the low temperature nitrogen gas adsorption methods. The results show that thetotal HA yields in the oxidized SFC increase with the oxidation temperature and the oxidationtime. The yields of different HA fractions for the pretreated SFC are in the increasing order ofHAI, HAII, HAIII. The mesopore system of pretreated SFC increases, while the specific surfacearea decreases.Zn/Mg/Al layered double hydroxides (Zn/Mg/Al-LDHs) were prepared by using theco-precipitation method, and effects of metal ion ratio, anion species, microwave andultrasound irritation, pH and the crystallization time on the composition, structure and thermalproperties of Zn/Mg/Al-LDHs were also investigated by using XRD, FTIR, SEM andTG-DSC analysis. The results indicate that the complexation and adsorption interactionbetween HAs and metal ions on the surface of LDH layers induce a bending growth ofZn/Mg/Al-CO3-LDH layers along the curved HA surface, which leading to theZn/Mg/Al-HAs-LDHs clusters with spherical shape. The uniformity of Zn/Mg/Al-LDHsparticles can be improved, and the particle size and the agglomeration degree can be decreased by microwave and ultrasound assisted co-precipitation method. The thermal stabilities ofZn/Mg/Al-LDHs are related to the metal ratio. When increasing Mg2+ion ratio, the thermalstabilities of Zn/Mg/Al-LDHs decrease, and their temperature range of endothermicdecomposition become broad.CLCs were prepared by using the in-situ co-precipitation method. The results show thatthe crystalline degree of CLCs decreases with increasing the mass fraction of SFC. Themorphology of Zn/Mg/Al-LDHs on the surface of CLCs can be controlled through changingthe oxidation temperature of SFC and the crystallization time. The controlling mechanism isthe coupling interaction of the complexation and adsorption between metal ions with thesurface functional group and the pore of SFC.The thermal properties of LDHs-SFC mixture and CLCs were studied by using theTG-DSC analysis method, and the prevention property of the coal spontaneous combustionwas also investigated. The results show that when Zn2Al1-CO3-LDHs, Mg2Al1-CO3-LDHs,Zn1Mg1Al1-CO3-LDHs are mechanically added in SFC, the critical temperature of SFCspontaneous combustion is higher when the loading amount is3%,5%and15%, respectively.The fire prevention efficiency is the highest when nano-fiberous Zn1Mg2Al1-CO3-LDHscomponents are dispersed in SFC in the CLCs composting form, because of the formation ofmetal oxides-carbon (LDOs-C) barrier from CLCs in coal spontaneous combustion process.The prevention mechanism of the coal spontaneous combustion process is the processes ofcoupling interaction between the exothermic oxidation process of SFC and the endothermicdecomposition process of Zn/Mg/Al-LDHs and CLCs. CLCs behave a special self-healingproperty.CLCs/EVA composites were prepared by using the blending method. The fire retardantproperties of CLCs/EVA composites were also evaluated by using the indexes such as the heatrelease rate, the limiting oxygen index and the UL94fire retardant level. The results show thatCLCs have higher fire retardants efficiency and smoke suppressing properties. The fireretardant level increases with increasing the filling amount of CLCs, so that, the synergy fireretardant effect lies in Zn/Mg/Al-LDHs with SFC. CLCs have significant strengthening andtoughening effect in CLCs/EVA composites.更多还原