Isauro Rivera
Universidad Autónoma del Estado de Hidalgo
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Hydrometallurgy | 2000
M. Cruells; A. Roca; Francisco Patiño; Eleazar Salinas; Isauro Rivera
Abstract The cyanidation of argentian potassium jarosite in alkaline media is characterized by an induction period, followed by a conversion period, as was observed in other synthetic jarosites. The induction period shows an apparent order of 0.7 (NaOH) and 0.2 [Ca(OH) 2 ] with respect to the [OH − ], and an apparent activation energy of 86 kJ mol −1 (NaOH) and 36 kJ mol −1 [Ca(OH) 2 ]. The conversion period is characterized by the presence of a reaction front with an unreacted jarosite core. The decomposition products are amorphous. The process is chemically controlled in both media. In NaOH–CN − , the order of reaction is 0.6 with respect to the [OH − ] and the activation energy is 43 kJ mol −1 . In Ca(OH) 2 –CN − , the order of reaction with respect to [OH − ] is 0.5 and the activation energy is 80 kJ mol −1 . The order of reaction with respect to the [CN − ] concentration is zero in both media. The process is faster than that observed in natural arsenical potassium jarosite from gossan ores (Rio Tinto, Spain). The addition of potassium chloride to the reaction system increases the reaction rate; the order of reaction with respect to the [Cl − ] was 0.13.
Journal of the Brazilian Chemical Society | 2011
Iván A. Reyes; Francisco Patiño; Isauro Rivera; Mizraim U. Flores; Martín Reyes; Juan Hernández
Jarosites are compounds that can undergo substitutions with several elements of environmental importance (such as As5+) during precipitation. Arsenic integrated in the structure could influence the solubility of the jarosite, potentially stabilizing the structure under a wide range of conditions that are tolerated by pure jarosite. Alkaline reactivity is characterized by the removal of sulfate and sodium ions from the lattice and by the formation of a gel consisting of iron hydroxides with adsorbed arsenate. The decomposition curves show an induction period, followed by a conversion period. The induction period is independent from the particle size and decreases exponentially as the temperature increases. The conversion period is characterized by the formation of a hydroxide halo around an unreacted arsenical natrojarosite core. The kinetic data are consistent with the chemical control of the process. The expression obtained in NaOH medium for [OH-] concentrations ranging from 3.84 × 10-3 to 1.08 × 10-1 mol L-1 is the following: r0/-v[1 - (1 - x)1/3] = 3.11 × 109 exp(-57.110/RT) [OH-]0.7 t. The expression in Ca(OH)2 medium for [OH-] concentrations ranging from 2.21 × 10-2 to 6.98 × 10-2 mol L-1 is the following: r0/-v[1 - (1 - x)1/3] = 9.22 × 1011 exp(-48.610/RT) [OH-]1.51 t.
Información tecnológica | 2013
Juan Hernández; Isauro Rivera; Francisco Patiño; Julio C. Juárez
Resumen Se ha realizado un estudio sobre la cinetica de lixiviacion de plata en el sistema S 2 O 32- -O 2 -Cu 2+ que se encuentra contenida en las escombreras de Dos Carlos del Estado de Hidalgo en Mexico. La concentracion de [S 2 O 32- ] influye considerablemente sobre la velocidad de lixiviacion obteniendose un orden de reaccion de 0.98 en el rango de 15.8 a 126.4 gL -1 , logrando recuperaciones de plata en solucion del 73%. Se ha analizado tambien el efecto de la temperatura y la adicion de cobre en la cinetica. La temperatura tiene una marcada influencia sobre la velocidad global de la reaccion en el rango de 15 a 60°C. Se logro disoluciones de plata del 97% a la mas alta temperatura estudiada, obteniendo un valor de 43 kJ mol -1 para la energia de activacion. La adicion de cobre favorecio la velocidad de lixiviacion de la plata, obteniendo un orden de reaccion de 0.35 respecto a la [Cu 2+ ] y alcanzando un 95% de plata lixiviada. Palabras clave: lixiviacion, cinetica, orden de reaccion, produccion de plata, residuos minerales
Información tecnológica | 2012
Julio C. Juárez; Isauro Rivera; Francisco Patiño; María Isabel Reyes
The effect of the temperature and thiosulfate concentration on the dissolution rate of silver contained in mining wastes, using the system S2O3 2- -O2–Zn 2+ was studied. In the State of Hidalgo in Mexico, thousands of tons of waste mining having around 71 grams of silver per ton of waste have been accumulated over the years. This is the main reason that motivates this study. It was observed that the temperature drastically affects the leaching rate of the silver showing an activation energy Ea= 55.85 kJ mol -1 , implying that the dissolution reaction is controlled by the chemical reaction. The thiosulfate concentration shows a considerable influence on the precious metal dissolution rate. The maximum silver dissolution was found to be approximately 97% at 45 °C and 40 gL -1 of [S2O3 2- ]. It is concluded that the process studied represents a good alternative
Characterization of Minerals, Metals, and Materials | 2015
Julio Cesar Juárez; Isauro Rivera; Francisco Patiño; Juan Hernández; Martín Reyes; Ma Ángeles de los Hernández
The dissolution of Ag contained in metallurgical tailings was studied by adding ions Cu2+ and Zn2+ in S2O32- medium. Chemical analysis of mine tailings by cupellation revealed a Ag concentration of 71 g/ton. The XRF and XRD analysis confirmed the preponderance of SiO2 in the mineral matrix. The experimental dissolution process was conducted in alkaline solution using six concentrations of NaOH and five of S2O32-, at different temperatures, also using five concentrations of Cu2+ and Zn2+ as a catalyst. The results showed similar values for both systems (96.8% and 97.13%). The ion Cu2+ and Zn2+ increases the dissolution of Ag, and decrease the reaction time of dissolution. Under the conditions used, pH and stirring rate did not affect the dissolution of Ag.
Hydrometallurgy | 2007
Isauro Rivera; A. Roca; M. Cruells; Francisco Patiño; Eleazar Salinas
Hydrometallurgy | 2015
Isauro Rivera; Francisco Patiño; A. Roca; M. Cruells
Revista de la Sociedad Química de Mexico | 2009
Martín Reyes; Francisco Patiño; Francisco J. Tavera; Ramiro Escudero; Isauro Rivera; Miguel Pérez
Journal of the Brazilian Chemical Society | 2012
Mizraim U. Flores; Francisco Patiño; Iván A. Reyes; Isauro Rivera; Martín Reyes; Julio C. Juárez
Geochemical Transactions | 2013
Francisco Patiño; Mizraim U. Flores; Iván A. Reyes; Martín Reyes; Juan Hernández; Isauro Rivera; Julio C. Juárez