Factors affecting lead jarosite formation

Dutrizac, J.E.; Dinardo, O.; Kaiman, S.

doi:10.1016/0304-386x(80)90022-5

Cited by 84 publications

(72 citation statements)

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“…by microbially mediated dissolution of pyrite in mine districts). 7) A preliminary experiment was carried out: the solubilities of jarosite formed at ambient temperatures 9) and synthesized by autoclaving 10) were examined. It was found that jarosite formed at ambient temperatures was almost all dissolved by 1 mol L −1 HCl-extraction, while jarosite synthesized by autoclaving almost all undissolved by 1 mol L −1 HCl-extraction.…”

Section: Resultsmentioning

confidence: 99%

Distribution and Transition of Heavy Metals in Mine Tailing Dumps

et al. 2002

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The vertical distributions of heavy metals and other elements in sediment core samples in a landfill of abandoned mine tailings were examined. Core samples were analyzed by XRF and XRD, and further examined by ICP-AES measurements after acid-sequential extraction with HCl, HF, and HNO 3 . According to XRD, the sediments contained α-quartz as the main component, and sericite, chlorite, rhodochrosite, pyrite, jarosite, sphalerite, and galena as minor components. A complete decomposition method using sequential extraction for the mine tailings sediments was established at ambient temperatures. Acid sequential extraction was useful for the analysis of minerals in mine tailings which are difficult to detect by XRD. Rhodochrosite and chlorite were dissolved by HCl-extraction, quartz and sericite by HF-extraction, and sulfides by HNO 3 -extraction. Rhodochrosite was the main source of high concentrations of Mn in mine drainage, highly distributed below the −100 cm zone in the mine tailings, combined with pyrite but not with sericite and quartz. The distributions of most heavy metals were related to those of pyrite.

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Section: Resultsmentioning

confidence: 99%

Distribution and Transition of Heavy Metals in Mine Tailing Dumps

et al. 2002

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“…Potassium jarosite was prepared according to the methods described in [4,30,31]. This involved dissolving Fe 2 (SO 4 ) 3 ·xH 2 0 (6.4 g) and KNO 3 (24 g) into 800 g de-ionised water in a clean, glass bottle.…”

Section: Jarosite Formationmentioning

confidence: 99%

Crystallization of Jarosite with Variable Al3+ Content: The Transition to Alunite

Jones

2017

Minerals

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This study focused on the formation of the jarosite-alunite solid solution at relatively low temperature, 90 • C. It was found that the transition from jarosite to alunite results in significant changes in the powder X-ray diffraction pattern, the infrared spectrum and thermal behavior when the degree of substitution reached ≥50%. The initial Al/(Al + Fe) in solution, however, required to achieve these substitution levels in the solid is ≥90%. The morphology shows that the faceted jarosite form goes through an intergrown transition to a spherical morphology of pure alunite. This morphology has not been previously observed for alunite and most likely reflects the formation temperature. Rietveld analysis shows that the a lattice parameter obeys Vegard's Rule while the c lattice parameter behavior is more complex. Empirical modelling of the incorporation of Fe into alunite supports the general trends found in the X-ray diffraction data for the behaviour of the a-axis with Al/Fe content. The dehydration of the Al 3+ ion could be a significant contribution to the activation energy barrier to alunite formation as found for other minerals. Finally, dynamic light scattering showed that the nucleation behavior for jarosite and Fe-containing alunite are significantly different. Alunite appears to nucleate continuously rather than in a single nucleation event.

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“…La presencia de hierro en la esfalerita reduce el valor de esta proporción, como consecuencia de la oxidación del ion ferroso y subsiguiente precipitación del ion férrico formado, según la reacción: que al generar ácido, neutraliza parte del amoníaco formado. En la citada figura 2 se ha dibujado en trazo continuo una línea recta de pendiente 1,48 que es el valor que corresponde a la relación amoníaco/cinc para la lixiviación del mineral de La Cavada, si ésta se realiza según las reacciones [4] y [5]. Los resultados experimentales obtenidos corroboran que la lixiviación se realiza según estas reacciones, ya que, como se ve en dicha figura, los valores experimentales para las tres temperaturas tienden a ajus- …”

Section: Reacciones Químicas De Ataqueunclassified

“…La figura 4 muestra, para estas tres temperaturas, la evolución de la concentración de amoníaco en función de la de cinc disuelto. En ella se ha dibujado la recta de pendiente 1,28 que es el valor que corresponde a la esfalerita del concentrado diferencial de cinc, teniendo en cuenta su contenido de hierro y según las reacciones [4] y [5]. Como se puede observar, los valores experimentales para porcentajes de cinc lixiviado bajos se ajus- …”

Section: Fig 2-nh 3 Produced Versus Zinc Leached At 100 110 Y 120 unclassified

Lixiviación oxidante de sulfuros complejos en soluciones de cloruro amónico: cinética de la lixiviación de la esfalerita

Limpo¹

1997

REVMETAL

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Lixiviación oxidante de sulfuros complejos en soluciones de cloruro amónico: cinética de la lixiviación de la esfalerita (#) J.L. Limpcr y Resumen Tras la revisión de las publicaciones recientes sobre la lixiviación de esfalerita en medio cloruro, se presentan los resultados obtenidos en el estudio de la cinética de la lixiviación oxidante con oxígeno de esfalerita en soluciones concentradas de cloruro amónico en presencia de ion cúprico. Este estudio se ha realizado sobre una esfalerita de gran pureza y un concentrado diferencial de cinc. En el intervalo de temperatura estudiado (80 a 130 °C) la disolución se produce de acuerdo con una cinética de control mixto según el modelo de "núcleo sin reaccionar", en el que tanto la difusión en la capa de azufre como la reacción química en el núcleo son etapas controlantes. La expresión matemática de este modelo es: [1-(1-X)Se ha estudiado la influencia que sobre la velocidad de reacción tiene la temperatura, tamaño de partícula y concentración de cúprico. Los valores de la energía de activación de da constante k r que se han obtenido para la esfalerita pura y el concentrado de cinc son, respectivamente, 66,4 y 67,6 kJ/mol. La velocidad de la disolución del cinc aumenta con la potencia 0,43 de la concentración de cúprico. Los resultados obtenidos de la influencia del tamaño de partícula (k T°c \/r 0 y Bocr 0 ), son los que teóricamente predice el modelo de control mixto, hecho que corrobora la validez de este modelo cinético.Palabras clave: Lixiviación. Esfalerita. Cinética. Medio cloruro amónico. Oxidizing leaching of complex sulphides in ammonium chloride: sphalerite leaching kinetics AbstractRecent studies on chloride leaching of sphalerite are rewieved. The kinetics of oxygen leaching of sphalerite in concentrated ammonium chloride solutions in the presence of cupric ion has been studied. A puré sphalerite and a zinc concéntrate have been tested. 80-130 °C temperature range, the dissolution occurred according to a mixed model which assumed both diffusion through sulfur layer and a surface reaction in the shrinking core model. This is described mathematically as: [1-(1-X)The effect of temperature, cupric concentration and particle size on the dissolution rate were determinated. The activation energy of the rate constant k r for the puré sphalerite and zinc concéntrate was found to be 66.4 and 67.6 kJ/mol respectively. The dissolution rate increased as the 0.43 power of the cupric cloride concentration. The results obtained for the effect of particle size show, such as it is predicted by the kinetic mixed model, that the rate constant k r is inversely related, and the parameter B is directly related, to particle radius.

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Factors affecting lead jarosite formation

Cited by 84 publications

References 1 publication

Distribution and Transition of Heavy Metals in Mine Tailing Dumps

Distribution and Transition of Heavy Metals in Mine Tailing Dumps

Crystallization of Jarosite with Variable Al3+ Content: The Transition to Alunite

Lixiviación oxidante de sulfuros complejos en soluciones de cloruro amónico: cinética de la lixiviación de la esfalerita

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