植酸与柠檬酸金属螯合剂组合对煤自燃的影响
The impact of the combination of phytic acid and citric acid metal chelating agents on coal spontaneous combustion
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摘要: 为了探究金属螯合剂植酸、柠檬酸以及植酸与柠檬酸组合对煤自燃的影响,利用热分析与红外光谱分析技术,分析加入螯合剂后,煤样的自燃特征温度点及煤中活性基团含量的变化规律,对比分析了不同螯合剂对煤自燃的抑制效果。研究结果表明,植酸、柠檬酸及两者组合对煤自燃均具有抑制作用。柠檬酸阻化煤样的燃点温度由351.10℃升至360.85℃,升高了9.75℃,同时分析红外光谱实验,煤体中活性基团甲基、亚甲基、羧基及羟基含量较原煤样下降,煤样在常温下更难以活化,自燃受到抑制;植酸阻化煤样的燃点温度由351.10℃升至383.05℃,升高了31.95℃,煤体中活性基团含量整体下降,降低幅度大于柠檬酸阻化煤样,抑制煤自燃效果优于柠檬酸;植酸与柠檬酸混合阻化煤样的燃点温度由351.10℃变为394.59℃,升高了43.49℃,煤体中活性基团含量较单类阻化煤样得到进一步降低,混合使用对煤自燃的抑制效果更加显著。此外,分析了两种螯合剂自身络合能力及其对煤体产生的影响,发现混合螯合剂产生的相互影响促进了其对煤自燃的抑制效果,产生了一定的协同作用。Abstract: This study investigates the influence of the metal chelating agents phytic acid,citric acid,and their combination on the spontaneous combustion of coal. Thermal analysis and infrared spectroscopy were employed to analyze the characteristic spontaneous combustion temperature points of coal samples and the changes in the content of active groups in coal after the addition of chelating agents. Furthermore,the inhibitory effects of the different chelating agents on coal spontaneous combustion were compared and analyzed. The results indicate that phytic acid,citric acid,and their combination exhibit inhibitory effects on coal spontaneous combustion. The ignition temperature of the coal sample treated with citric acid increased from 351. 10 ℃ to 360. 85 ℃,an increase of 9. 75 ℃. Additionally,infrared spectroscopy revealed that the contents of methyl,methylene,carboxyl, and hydroxyl groups in the coal were lower than those in the raw coal sample,indicating that the coal sample becomes more resistant to activation at room temperature, thereby inhibiting spontaneous combustion. The ignition temperature of the coal sample treated with phytic acid increased from 351. 10 ℃ to 383. 05 ℃,reflecting an increase of 31. 95 ℃. The overall decrease in the content of active groups in the coal was more pronounced than that observed in the citric acid-treated samples,suggesting that phytic acid is more effective in inhibiting spontaneous combustion. The ignition temperature of the coal sample treated with a combination of phytic acid and citric acid rose from 351. 10 ℃ to 394. 59 ℃,an increase of 43. 49 ℃. The content of active groups in this mixed treatment was further reduced compared to the individual treatments,demonstrating that the combined use of phytic acid and citric acid significantly enhances the inhibition of coal spontaneous combustion. Furthermore,an analysis was conducted on the complexation capabilities of the two chelating agents and their effects on the coal matrix. The interplay between the mixed chelating agents enhances their inhibitory effect on the spontaneous combustion of coal,producing a notable synergistic effect.