Browsing by Author "Ali, Babiker"

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Citation - WoS: 1
Citation - Scopus: 1
The Investigation of Metallic Silver Dissolution Kinetics Using DL-Malic Acid With Hydrogen Peroxide Solution as an Eco-Friendly Leaching System: The Rotating Disc Method
(Springer, 2025) Motasim, Mahmoud; Boyrazli, Mustafa; Aydogan, Salih; Agacayak, Tevfik; Ali, Babiker
Although cyanidation remains widely employed for silver recovery due to its cost-effectiveness, it presents serious environmental and health hazards. In this study, the dissolution kinetics of silver were investigated in an environmentally benign leaching system composed of DL-malic acid and hydrogen peroxide, employing the rotating disc method. High-purity silver discs (99.99 pct) were used to examine the effects of rotation speed, disc surface area, temperature, and the concentrations of DL-malic acid and hydrogen peroxide on the leaching rate. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) were conducted to characterize the silver surface before and after leaching. Additionally, contact angle measurements were performed to evaluate the interfacial interaction between the leaching solution and the silver surface. The results demonstrated that the dissolution rate increased with temperature, rotation speed, hydrogen peroxide concentration, and surface area. However, elevated concentrations of DL-malic acid resulted in the formation of a passivating layer on the silver surface, likely due to chelation effects, which significantly impeded the access of protons (H+) to the silver surface, thereby reducing the dissolution rate. Contact angle analysis further indicated reduced wettability at higher DL-malic acid concentrations, with values reaching up to 87.80 deg. XRD analysis confirmed the partial oxidation of the silver surface, forming Ag2O. The reaction was determined to be chemically controlled, with an activation energy of 44.14 kJ/mol.
Citation - WoS: 2
Citation - Scopus: 2
Kinetics Study on the Leaching of Metallic Silver With Ammonium Carbonate as an Eco-Friendly Alternative for Cyanide
(Springer, 2025) Aydogan, Salih; Abdelraheem, Mohamed Taha Osman; Ali, Babiker; Boyrazli, Mustafa
This article describes the dissolution kinetics of metallic silver (Ag) in ammonium carbonate and hydrogen peroxide (H2O2) solution. The influences of temperature, rotation speed, H2O2 concentration, and ammonium carbonate concentration were investigated. The results indicate that ammonium carbonate concentrations between 0.025 and 0.1 M have a significant impact on the dissolution rate. The dissolution rate is positively impacted by H2O2 concentrations between 0.025 M and 0.10 M. Furthermore, there is a positive relationship between the dissolution rate of Ag and the rotation speed. Silver dissolves more readily at temperatures between 20 degrees C and 55 degrees C. However, a temperature > 40 degrees C led to the formation of a silver carbonate layer on the disc when using high concentrations of hydrogen peroxide and ammonium carbonate. The activation energy of 11.10 kJ/mol was calculated, supporting the validity of the Levich equation, which is predicated on the suggestion that mass transfer control describes the extraction rate.
Citation - WoS: 4
Citation - Scopus: 4
Leaching Kinetics of Metallic Silver Using Di-Ammonium Tartrate and Hydrogen Peroxide Solution as a Greener Substitute for Cyanide
(SPRINGER, 2024) Aydogan, Salih; Abdelraheem, Mohamed Taha Osman; Ali, Babiker; Boyrazlı, Mustafa
The kinetic of dissolving pure metallic silver in di-ammonium tartrate with a hydrogen peroxide solution is discussed in this article. The effects of temperature, di-ammonium tartrate concentration, hydrogen peroxide concentration, and rotation speed were examined. The findings show that there is a favorable correlation between the rotation speed and the rate of silver dissolution. Moreover, a very tiny concentration of di-ammonium tartrate, between 0.005 and 0.125 M, has a beneficial impact. The dissolution rate is well-affected by hydrogen peroxide concentrations between 0.05 and 0.25 M, but not significantly so in the 0.25-0.35 M range. Temperatures between 20 and 50 degrees C have a positive effect because hydrogen peroxide is stable in this range. A measurement of 25.44 kJ/mol was made of the apparent activation energy.