201×7树脂对Fe(CN)64-吸附的热力学与动力学

Thermodynamics and kinetics of Fe(CN)64- adsorption onto 201×7 resin

  • 摘要: 针对离子交换法处理氰化提金尾液时Fe(CN)64-的存在引起交换剂的"铁中毒"问题,采用Freundlich、Langmiur、准二级动力学方程以及范山鹰的扩散模型,从热力学与动力学角度研究了201×7树脂对Fe(CN)64-的吸附特性,并计算了相关热力学常数和表观活化能.结果表明:Fe(CN)64-在该树脂上的吸附能自发进行,且符合Langmiur方程和准二阶动力学方程,吸附初期表现为膜扩散,后期表现为空隙扩散.扩散到固定层中的Fe(CN)64-由于被树脂表面的官能团紧紧固定,导致负载树脂在硫酸脱氰过程形成Zn2Fe(CN)6和Cu2Fe(CN)6附着在树脂上,引起树脂的"铁中毒",可通过选择性沉淀先除去Fe(CN)64-.

     

    Abstract: To solve the problem of Fe(CN)64- causing "iron poisoning" when cyanide-bearing waster water was treated with an ion exchange method, the adsorption properties of Fe(CN)64- onto 201×7 resin were studied by using the Freundlich adsorption equation, the Langmuir adsorption equation, the pseudo-second order equation and the Fan Shan Yang model from thermodynamics and dynamics. The related thermodynamic constant and the apparent activation energy were calculated. The results show that Fe(CN)64- adsorption onto the resin can occur spontaneously. The process conforms to the Langmuir equation and the pseudo-second order equation. It is controlled by film diffusion at the initial stage, but by gap diffusion at the later stage. Fe(CN)64- exchanging to the stern layer is fixed by resin functional groups strongly leading to "iron poisoning" of the resin for generating Zn2Fe(CN)6 and Cu2Fe(CN)6 which adhere on the resin during the process of cyanides removed from the loaded resin with H2SO4. Fe(CN)64- in cyanide-bearing waster water can be removed by selective precipitation.

     

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