[13] H.Y. Sohn, and M.E. Wadsworth, Cinética de los procesos de metalurgia extractiva, Edited by Trillas, Mexico City, Mexico, , p [14] A.R. Geyne, C. 1 Centro de Investigaciones en Materiales y Metalurgia, Universidad Sohn, H. Y.; Wadsworth, M. E., Cinética de los Procesos de la Metalurgia Extractiva, Ed. 3Instituto de Metalurgia, Universidad Autónoma de San Luis Potosí, Av. Sierra .. [12] A. Ballester, L.F. Verdeja, and J. Sancho, Metalurgia Extractiva, Vol. 1, [13] H.Y. Sohn, and M.E. Wadsworth, Cinética de los procesos de metalurgia.

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It is important to note that, during the alkaline decomposition process, arsenic was not detected in the samples analyzed by AAS and ICP.

Civil en Metalurgia Extractiva. R; Handbook of Chemistry and Physics89 th ed. 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. In order to study the stoichiometry of the reaction, samples of arsenical natrojarosite were treated for long periods with NaOH and Ca OH 2.

The manner in which the arsenic is incorporated into the jarosite can influence the mobility and bioavailability of arsenic in controlled or natural environments.

The conversion period is characterized by the formation of a hydroxide halo around an unreacted arsenical natrojarosite core. The arsenic pollution of water is considered a problem of catastrophic proportions.

This is due to the different coordination environments in the position of the cations or to the substitution of SO 4 2- by oxoanions formed by these elements AsO 4 3-CrO 4 The kinetic data are consistent with the chemical prodesos of the process. The resulting chemical composition 4.


Oscar Jaime Restrepo Baena

The data are consistent with the model Figure 6. As a consequence, Germany reduced its limit to 0. The alkaline decomposition of the arsenical natrojarosite is characterized by the removal of sulfate and sodium ions from the lattice and their diffusion to the solution, while a gel of iron hydroxide with adsorbed arsenate is formed. Patricio Proust Crovetto Thus, the use of innovative techniques for the elimination of arsenic is an important subject.

Alkaline reactivity of arsenical natrojarosite

Therefore, in this case, the rate constants are inversely proportional to the square of the initial diameter d 0. Valentina Alliende vice presidenta. Horacio Soto Aguilera The decomposition of the arsenical natrojarosite presents an induction period and a conversion period. extfactiva

N-methylformamide-water mixtures at In NaOH medium, the decomposition of the arsenical natrojarosite is of a fractional order of 0. Madrid,chapter 2.

Kinetic Modeling of the Alkaline Decomposition and Cyanidation of Argentojarosite

Samuel Navarrete Cifuentes This kind of dependence is related to the chemical control; therefore, it is incompatible with the control by diffusion of reactants through the layer of the product. The study provides the kinetics and nature of the cinehica reaction topology, reaction rates and dependence of the reaction on variables such as medium concentration, temperature and particle size.

The arsenic is retained in the residual solids even for times subsequent to the alkaline decomposition. The values of the induction times t ind were obtained from the intersections of the regression straight line with the time axis. Manuel Soto vice presidente.


Sergio Pinedo Fuenzalida The OH – concentration was calculated on the base of the pH of the solution, and the ionic constant of the water was extrachiva on the base of the working temperature.

The model selected for the conversion period was the model of decreasing core and chemical control, which, for particles, takes the following expression: Jorge Coloma Apoyo Laboratorios. Therefore, jarosites containing arsenic have an environmental importance, not only as a means to control the As in water, but it is also well known that the hydrometallurgical industries, mainly the zinc industry, use jarosite precipitation as a metalrgia to control iron, sulfates and alkaline metals among others.

The experimental data are consistent with the spherical particle model with decreasing core and chemical control. Barcelona,chapter During the induction period, there are no morphological metalurbia or formation of any detectable solid layer at practical resolution levels of the EDS technique ca. In Ca OH 2 medium, the reaction order was of 1. The solids examination by EDS after the induction period indicates the presence of a reaction front with an unreacted arsenical natrojarosite core and a gel halo of iron hydroxide with adsorbed arsenate.

Juan Pablo Squella presidente.