Kinetic modeling and experimental design of the sodium arsenojarosite decomposition in alkaline media: Implications

Kinetic Analysis of the Decomposition of the KFe3(SO4)2-x(CrO4)x(OH)6Jarosite Solid Solution in Ca(OH)2Medium

“…39 A number of previous experiments were conducted to select the kinetic model that best describes the behavior of the decomposition reactions. Residual solids were characterized by XRD and SEM-EDS.…”

“…28,36,[38][39][40][41][42] Site Z is fully occupied by SO 4 2− in the potassium jarosite, but it can be substituted by varying the amount of chromate until it is completely substituted. 43 It was observed that, the larger the radius of the ions that incorporate in the anionic site, the bigger the difficulty to compete with the SO 4 2− ion.…”

Determination of Dissolution Rates of Ag Contained in Metallurgical and Mining Residues in the S2O32−-O2-Cu2+ System: Kinetic Analysis

“…Thus, it would seem that the thiosulfate system is the most promising for metal extraction, as it can increase the dissolution rate of metals, and because, compared to cyanide, it is a selective method for refractory ores [10,22]. Another alternative that has been studied (in the laboratory) in previous works on the leaching of silver in sulfide or metal form with thiosulfate, is the addition of metal ions Zn 2+ and Cu 2+ , where these two oxidize the noble metals while thiosulfate forms stable complexes.…”

The Behavior of Arsenic during the Thermal and Chemical Decomposition of the Ammonium–Arsenic Jarosite

“…In a recent study on the decomposition of an arsenic-containing jarosite compound in alkaline media [11,12], it was found that arsenic remained in the decomposition product, mainly as a constituent of amorphous iron hydroxide. There are few works on the dissolution and stability of such compounds, making the data insufficient for evaluating the real environmental risk caused by the improper disposal of the generated precipitates [13].…”

“…Studies on the dissolution of natural and synthetic jarosites not containing arsenic had been carried out at different pH conditions. It has been found that those jarosites remained stable at highly acid and oxidizing conditions [14] and that dissolution is faster at alkaline pH than in acidic media; besides, it was observed than dissolution occurs in an erratic manner [12]. Therefore, in this article a study on the reactivity of an ammonium-arsenic jarosite is presented, with the aim to provide information regarding the stability of As in such a compound, at extreme conditions of alkaline pH and temperature.…”