Kinetic Aspects and Thermo chemical Analysis of Silver Cementation from Residual X Ray Fixer by Cementation on Zinc

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Authors

  • M. Pérez-Labra Academic Area of Earth Sciences and Materials. Autonomous University of Hidalgo State. Road Pachuca- ,Tulancingo Km 4.5 Mineral de la Reforma Zip Code 42184, Hidalgo México
  • J. A. Romero-Serrano Metallurgy and Materials Department, ESIQIE-IPN. UPALM, Zacatenco, Zip Code 07738, México D.F.
  • M. Reyes-Pérez Academic Area of Earth Sciences and Materials. Autonomous University of Hidalgo State. Road Pachuca- ,Tulancingo Km 4.5 Mineral de la Reforma Zip Code 42184, Hidalgo México.
  • F. R. Barrientos-Hernández Academic Area of Earth Sciences and Materials. Autonomous University of Hidalgo State. Road Pachuca- ,Tulancingo Km 4.5 Mineral de la Reforma Zip Code 42184, Hidalgo México
  • A. Hernández-Ramírez Metallurgy and Materials Department, ESIQIE-IPN. UPALM, Zacatenco, Zip Code 07738, México D.F.
  • J. C. Juarez-Tapia Academic Area of Earth Sciences and Materials. Autonomous University of Hidalgo State. Road Pachuca- ,Tulancingo Km 4.5 Mineral de la Reforma Zip Code 42184, Hidalgo México
  • V. E. Reyes-Cruz Academic Area of Earth Sciences and Materials. Autonomous University of Hidalgo State. Road Pachuca- ,Tulancingo Km 4.5 Mineral de la Reforma Zip Code 42184, Hidalgo México.
October 20, 2017

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Silver cementation with zinc from residual X ray fixers  was studied. The chemical analysis of XRF showed 5.16 g L-1 (Ag), 0.56 g L-1 (Al), 5.24 g L-1 (K), 7.02 g L-1 (Na) and 172.56 g L-1 (S). The process was thermodynamically simulated using Fact Sage software by constructing the potential-pH diagram at 298.15 K (25ºC). This diagram showed that the process leads to metallic silver together with residual unreacted zinc. The parameters experimentally evaluated were: pH (ranged from 3.0 to 7.0), temperature (ranged from 298.15 K (25°C) to 318.15 K (45°C)) and the Ag:Zn weight ratio (1:1, 1:2, 1:3, 1:4 and 1:5). The maxim silver cementation (99.99 % Ag) was obtained at 90 s of reaction, pH 6.0, 318 K (45°C) and Ag:Zn equal to 1:3. Silver cementation increases whit the Ag:Zn weight ratio, pH and temperature increases. The X-Ray and SEM-EDS results showed that the cementation product is formed by Ag and Zn.