顺序萃取法研究浸渍炭金属组分和防护反应产物

Study on metal compounds and protective reaction products of impregnated activated carbon by sequential extraction method

采用H_(2)O-H_(2)SO_(4)和H_(2)O-NaOH顺序萃取法,考查和分析了ASC浸渍炭负载金属(Cu、Cr和Ag)在不同萃取液和残渣中的含量和分布,以及其染毒(HCN或CNCl)后样品在水相萃取液和残渣中金属离子、NH_(4)^(+)、CN^(-)和Cl^(-)离子的含量和分布。结果表明,浸渍炭负载金属氧化物的形态为CuO、CrO_(3)、Cr_(2)O_(3)和Ag_(2)O,其中金属Cr或以(NH)CrO_(3)的形式存在。这些金属氧化物在防护HCN或CNCl过程中发生形态变化,即CrO_(3)还原为CrO_(3),CuO转化为水溶态的Cu^(2+)(如CuCl_(2))。此外,染毒浸渍炭样品表面还发现有NH_(4)^(+)离子或可离解为NH_(4)^(+)离子的氨基化合物。

Using sequential extraction methods H_(2)O-H_(2)SO_(4)and H_(2)O-NaOH,the contents and distribution of loaded metals(Cu,Cr and Ag)in each extract and residue of ASC impregnated carbon were investigated and analyzed,as well as the content and distribution of metal ions,NH,CNand Clions in the aqueous extraction solution and residues of the carbon samples against poison gas(HCN or CNCl).The results showed that the metal oxides loaded on the carbon were CuO,CrO_(3),Cr_(2)O_(3)and Ag_(2)O,of which CrO_(3)would be in the form of(NH)CrO_(3).These metal oxides undergo changes in species by the chemical reaction of CrO_(3)reduction to CrO_(3)and the conversion of CuO into a water-soluble Cu^(2+)(such as CuCl_(2))during the protection against HCN or CNCl.In addition,NHions or amino compounds that can be dissociated into NH_(4)^(+)ions were also found on the surface of the contaminated impregnated carbon samples.