Thermodynamic analysis of stability in iron removal from kaolin by using oxalic acid

Cerâmica

C. Ocampo-lópez¹  M. E. Ramírez-carmona¹  E. Vélez-ortiz¹ 

[1] ,Universidad Pontificia Bolivariana Facultad de Ingeniería Química Medellín,Colombia

关键词: kaolin;    iron removal;    thermodynamic study;    organic acids;    caulim;    remoção de ferro;    estudo termodinâmico;    ácidos orgânicos;   

DOI  :  10.1590/S0366-69132013000200019

来源: SciELO

【 摘 要 】

The graphical representation of global stability for a system, or Pourbaix diagram, was constructed to perform a thermodynamic study of iron removal from kaolin using oxalic acid as an oxidant. To do this the free energies of formation of the oxalate complex of the system were calculated, and it was found that the more stable specie is Fe(C2O4)3-3, with a calculated free energy of formation of -3753.88 kcal/mol. Thermodynamic stability functions were estimated for the system as a function of pH and Eh known as potential of oxide reduction. It was built a global stability diagram for the removal system; it showed that the specie trioxalate Fe(C2O4)3-3 is the only oxalate in equilibrium with other compounds associated with the removal of iron in kaolin.

【 授权许可】

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