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Investigation into the surface active groups of coal 总被引:2,自引:0,他引:2
The oxidation heat of coal is the direct reason leading to coal spontaneous combustion. When coal is exposed in oxygen atmosphere, the physical adsorption and chemisorption happened, and then which resulting chemical reaction followed heat between coal and oxygen. Owing to the complexity and uncertain of molecular structure of coal, it was only reduced that bridge bonds, side chains and O2-containing functional groups in coal may be prone to oxidation in last year, but not to deeply investigate into the structures and the type of the active radicals. In this paper, according to the last achievements in coal structure research, the hypomethylether bond, hypoalkyl bond of (z-carbon atom with hydroxyl and α-oarbon atom with hypomethy side chain andhypomethyl bonds linking up two aromatic hydrocarbon in bridge bonds, and methoxy, aldehydeand alkyls of α-carbon atom with hydroxy in side bonds are inferred to be free radical easily to lead to oxidize coal under the ambient temperature and pressure. The order from strong to weak of oxide activation of the seven surface active groups is aldehyde side chains, hypomethylether bonds, hypoalkyl bonds of α-carbon atom with hydroxyl, hypoalkyl bonds of α-carbon atom with hypomethyl, hypomethyl bonds linking up two aromatic hydrocarbon, methoxy, alkyls side chains of α-carbon atom with hydroxyl. Because of the two unsaturated molecular tracks of O2 unpaired electron clouds of the part of surface active groups of coal enter molecular tracks of O2 to lead to chemisorb on the conjugate effect and induced effect of surface active groups, and then chemical reaction followed heat happens in them. On the basis of change of bond energy, weighted average method is adopted to count the reaction heat value of each tool CO, CO2 and H2O. The property of coal spontaneous combustion is different for the different number and oxidability of the active structure in the coal resulting in the different oxidation heat. 相似文献
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考查了离子测量法在浮选药剂制度最佳化应用中的可能性。该法可为工业浮选条件做图,并可为实验室试验快速选择浮选药剂制度。浮选药剂用量控制系统的工业应用可使精矿回收率平均提高2%。 相似文献
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何启林 《煤炭学报(英文版)》2008,14(4):554-557
Based on experiment results and theoretical analysis, pointed out that the method of coal susceptibility to spontaneous combustion
determination with fluid oxygen adsorption can not present the essence of coal oxidation process and oxidation reaction. The
method is incorrect, paying attention at one aspect and ignoring the rest. The method is not reasonable for coal susceptibility
to spontaneous combustion determination. Susceptibility to spontaneous combustion of coal reflects chemical property of coal
oxidation with oxygen absorption and heat release at low temperature. Coal’s susceptibility to spontaneous combustion is mainly
decided by the number of molecules with reaction activation energy and activation molecule production rate at certain temperature.
Therefore, index of susceptibility to spontaneous combustion should adopt accumulative value or trend of heat release or oxygen
adsorption during oxidation process.
Supported by Innovative Team in Science and Technology of Anhui Province College and Universities(2006KJ005TD); Science of
Fire, Nature Science Foundation of China(2001CB409600) 相似文献
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TG-DTA-FTIR技术对煤氧化过程的规律性研究 总被引:4,自引:0,他引:4
利用TG-DTA-FTIR联用技术,测定煤升温氧化过程不同阶段起始温度、吸氧量、放热量、释放气体初温与成分以及燃点等参数,提出了用某个温度下煤的吸氧量或在整个氧化阶段总吸氧量来表示煤的自燃倾向性高低的不合理性;给出了用100~200 ℃温度段的吸氧速率q′T指标进行煤自燃倾向性高低评判方法. 相似文献
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氧化铜矿矿浆电爆处理可以对要浮选的 物表面进行高质量的制备,强化矿物集合体破碎,提高矿物的解离度,改善矿物表面暴露程度和相转变,提高硫化剂在矿物表面上的吸附量。因此,氧化铜矿矿浆电爆处理可以提高浮选指标,降低还原剂用量。 相似文献
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分析了环已烷氧化机理和工艺控制原理,指出了环已烷催化氧化法在生产中的一些控制要点,对实际生产有一定的指导意义。 相似文献
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为了研究煤在自燃过程中会出现温度上升突然加快所产生的原因,为煤矿现场煤炭自然火灾的防治工作提供理论依据,采用绝热法、程序升温法对北皂褐煤氧化过程中自热升温特性、耗氧、CO,CO2气体产物特性的研究,提出煤的氧化过程具有分阶段性,主要可以分为2个阶段:低温缓慢氧化阶段和高温快速氧化阶段;并采用原位傅里叶红外光谱实时连续地采集了北皂褐煤表面主要活性官能团在氧化过程中的变化规律。实验结果表明:煤的分阶段特性主要是由于OH的反应导致的,OH反应吸热是低温阶段热量难以积聚的主要原因,当OH反应消耗殆尽时,煤中热量迅速积聚,煤温迅速升高。 相似文献
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铜精炼阳极炉氧化过程炉膛烟气温度动态模型 总被引:1,自引:1,他引:1
基于能量平衡原理,建立了铜精炼阳极炉氧化过程炉膛烟气温度变化动态响应模型。由此动态响应模型及其应用可知,当重油质量流量、助燃空气消耗系数、氧化空气质量流量扰动幅度均为其静态值的0 1倍时,重油质量流量扰动、助燃空气消耗系数扰动对炉膛内烟气温度变化影响较大,而氧化空气质量流量扰动相对前二者来说,影响要小得多;且铜精炼氧化过程炉膛具有很大的热惯性,这直接导致炉膛烟气温度动态响应速度很慢、动态过程时间很长的现象出现。此动态模型有利于铜精炼阳极炉的在线优化控制。 相似文献
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铝合金型材在大气中易被腐蚀,阳极氧化膜能提高材料的抗腐蚀性能。讨论了电解液硫酸浓度、溶液温度、氧化时间,电流密度对氧化膜质量的影响。选择硫酸浓度为15%~20%,温度为(20±1)℃,时间为(30±2)min,电流密度1~15A/dm2的工艺条件,取得了厚度10~12μm,抗腐强度9级,硬度为351Hv的各种颜色铝合金型材。 相似文献
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通过改变氧化剂用量制备不同氧化程度的氧化石墨(GO),经超声分散,水热还原制备出系列三维还原氧化石墨烯(3D r GOs),采用扫描电镜、X射线衍射、红外光谱、拉曼光谱和紫外可见分光光度计等分析测试手段研究了氧化程度对3D rGOs形貌结构、光谱特征和吸附性能的影响。结果表明:随着氧化程度的增加,水热还原产物在微观上由多层堆积的片状结构逐渐转向均匀多孔网状结构,最后转变为断裂碎片交联的网状结构。吸附容量随氧化程度的增加先增大后减小,当GO羟基含量最多而环氧基含量最少时,3D rGOs吸附性能最好,对罗丹明B、亚甲基蓝和甲基紫吸附量最高分别可达90.9、145.4和237.4 mg/g。 相似文献