在氧度度的影响下,可变浸泡时间的煤的二次氧化风险研究
Wanting Zhao1,2,3, Ziwen Dong1, Xian Wu2,3
1School of Safety Engineering, Ningbo University of Technology, Ningbo, Zhejiang 315211, China.
ACS omega
|November 25, 2024
概括
在水中浸泡的煤有自燃的风险. 短期 (STWIC) 和长期 (LTWIC) 浸水煤的二次氧化在较低的氧气水平 (8-18%) 中带来更高的风险,较低的激活能量表明危险性增加.
科学领域:
- 地质化学 地质化学
- 煤炭科学 煤炭科学 煤炭科学
- 环境科学 环境科学
背景情况:
- 在采矿中,goaf的自发燃烧是采矿的重大风险.
- 煤的低温氧化是自燃的一个关键因素.
- 水浸沉会影响煤炭的氧化行为和自燃倾向.
研究的目的:
- 为了研究浸水红的低温氧化特性.
- 评估在不同氧气度下短期 (STWIC) 和长期 (LTWIC) 浸水煤的自燃风险.
- 为确定GOAF的自燃区提供理论基础.
主要方法:
- 在煤上进行了初级和二级低温氧化实验.
- 不同的浸泡时间 (50天和200天) 和氧气度 (8%,18%,21%).
- 测量了明显的激活能量 (Ea),温度转折点,氧气消耗率,释放热量的强度和气体生成 (CO,CO2).
主要成果:
- STWIC和LTWIC的二次氧化显示出较低的明显激活能量 (Ea) 比18%氧的初级氧化,这表明自发燃烧风险更高.
- STWIC和LTWIC更容易受到二次氧化,即在8%和18%的氧气下自燃.
- 观察到一个温度拐点,随着氧气度的增加而下降;超过这个点,初级氧化显示出更高的氧气消耗和热释放,而不是STWIC的二次氧化.
结论:
- 沉浸在水中会影响煤的自燃行为,不同的沉浸时间和氧度起着关键的作用.
- 较低的氧气度 (8-18%) 增加了浸水煤中二次氧化自燃的风险.
- 与STWIC相比,LTWIC在二次氧化过程中表现出较低的CO和CO2生成率,这表明氧化途径发生了变化.
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