Effect of additives on stabilization and inhibition of mercury re-emission in simulated desulphurization slurry
Effect of additives on stabilization and inhibition of mercury re-emission in simulated desulphurization slurry
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DOI：
10.1007/s13762-019-02301-x
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发表时间：
2019-12
影响因子：
3.1
通讯作者：
Hao Wu;J. Sun;Changsong Zhou;Hongmin Yang
中科院分区：
文献类型：
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作者：
Hao Wu;J. Sun;Changsong Zhou;Hongmin Yang
在脱硫浆液中引入添加剂可以抑制浆液中汞的再排放，提高浆液中汞的稳定性。本文在典型操作条件下研究了硫化钠（Na2S）、2,4,6-三巯基三嗪三钠（TMT-18）、二硫代氨基甲酸钠（DTCR-2）和芬顿试剂等常用添加剂对气液固相汞分布的影响。同时研究了不同添加剂用量对抑制汞再排放性能的影响。此外，还讨论了不同添加剂的抑制机制。实验结果表明，Na2S、TMT-18、DTCR-2和Fenton试剂均能抑制脱硫浆液汞的再排放，部分可能先进入气相的汞被抑制在固相中。对于Na2S、TMT-18、DTCR-2等添加剂，随着添加剂用量的增加，抑制汞再排放的性能有所提高，但增强效果趋于平稳。通过形成HgS、Hg-TMT和Hg-DTCR，可以将更多的汞限制在固相中。而对于Fenton试剂等添加剂来说，随着Fenton试剂中Fe2+和H2O2比例的增加，抑制汞再发射的性能先增加后减少。存在一个最佳比例。 Fenton试剂在Fe2+催化下产生的氧化自由基是抑制汞再释放的主要原因，更多的汞会被氧化，并因形成HgSO4和Fe(OH)3而被限制在固相中。
The introduction of additives into desulfurization slurry may inhibit the mercury re-emission from slurry and improve the stabilization of mercury in slurry. In this paper, the effect of common additives, such as sodium sulfide (Na2S), 2,4,6-trimercaptotriazine trisodium (TMT-18), sodium dithiocarbamate (DTCR-2) and Fenton reagent, on mercury distribution in gas–liquid–solid phase was investigated under typical operating conditions. Meanwhile, the effect of different additive dosages on the inhibition performance of mercury re-emission was studied. Furthermore, the inhibition mechanisms of different additives were also discussed. The experimental results showed that Na2S, TMT-18, DTCR-2 and Fenton reagent could inhibit the mercury re-emission from desulfurization slurry and some mercury that might reemit into the gas phase before would be restrained in the solid phase. For additives such as Na2S, TMT-18 and DTCR-2, with the increase in additive dosages, the inhibition performances of mercury re-emission were improved, but the enhancing effects tended to level off. More mercury could be restrained in the solid phase by forming HgS, Hg-TMT and Hg-DTCR. However, for additives such as Fenton reagent, the inhibition performance of mercury re-emission was first increased and then decreased with the proportion of Fe2+and H2O2in Fenton reagent increasing. There existed an optimal proportion. The oxygenated free radical generated by Fenton reagent with Fe2+as catalysis was the main reason for the inhibition of mercury re-emission, and more mercury would be oxidized and then restrained in solid phase due to the formation of HgSO4and Fe(OH)3.