Briquetting technique can be an excellent energy saving utilization of pulverized coal, and the thermal chemical treatment of briquette has attracted the extensive attention of researchers due to its efficiency and applicability. To reveal the migration and volatilization characteristic of toxic trace elements (As, Se and Cd) during pyrolysis procedure of briquette, this paper studied the effects of mineral composition, pyrolysis parameters and occurrence state on element migration by multidisciplinary methods. Results show that the migration of toxic elements from solid phase to tar and gas phase are accelerated by increasing the pyrolysis temperature. Except for temperature, both the occurrence states and lower boiling point jointly determine release of element Se, while release behavior of As and Cd is mainly attributed to the occurrence states. At the pyrolysis temperature interval of 500–800 °C, the volatilization ability of toxic elements following the trend of Se > Cd > As. The element oxides SiO have a strong affinity to elements Cd and As with high correlation index, which play a key role on Cd and As elements absorption during heat treatment to prevent emission. Due to the easily vaporized characteristics of Se, some other suitable measures should be explored to reduce environmental pollution.

中文翻译：

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型煤热解过程中有毒元素的迁移和挥发

成型技术是一种优良的煤粉节能利用技术，而型煤的热化学处理因其高效性和适用性而受到研究者的广泛关注。为揭示型煤热解过程中有毒微量元素As、Se、Cd的迁移和挥发特征，采用多学科方法研究了矿物成分、热解参数和赋存状态对元素迁移的影响。结果表明，提高热解温度会加速有毒元素从固相向焦油和气相的迁移。除温度外，赋存状态和低沸点共同决定Se元素的释放，而As和Cd的释放行为主要归因于赋存状态。在热解温度500~800 ℃区间，有毒元素的挥发能力呈现Se>Cd>As的趋势。元素氧化物SiO与Cd、As元素有很强的亲和力，关联指数高，对热处理过程中Cd、As元素的吸附防止发射起到关键作用。由于硒易蒸发的特性，应探索其他合适的措施来减少环境污染。