Synthesis and nature of the reaction of a solid solution of ammonium-potassium arsenojarosite in NaOH medium

J. Eliecer Méndez, Mizraim U. Flores, Francisco Patiño, Martín Reyes, Julio C. Juárez, Iván A. Reyes, Elia G. Palacios

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

1 Scopus citations

Abstract

A solid solution of ammonium-potassium arsenojarosite was synthesized for this study. It was chemically and mineralogically characterized by Inductively Coupled Plasma Spectrometry (ICP), elemental analysis, Atomic Absorption Spectrophotometry (AAS), X-Ray Diffraction (XRD) and Scanning Electron Microscopy with Energy-Dispersive X-Ray Spectroscopy (SEM-EDS). The following composition was obtained: 26.67 % Fe, 36.41 % SO4, 3.60 % K, 1 % NH4, 6.71 % AsO4 and 25.61 % OH+H2O, which results in the following approximate formula: [(NH4)0.23K0.77] Fe2.47 [(SO4)1.69(AsO4)0.31] [(OH)4.1(H2O)1.9]. The amount of arsenic was higher than the reported by different authors who have synthesized similar compounds. The XRD results confirm that the obtained sample corresponds to ammonium-potassium arsenojarosite. The granulometric analysis showed that the main particle sizes are 38 and 25 µm, corresponding to mesh sizes 400 and 500. This indicates that a fine size particle was obtained. The compound’s nature of thereaction in NaOH was studied as well, showing an induction period characterized by the formation of active sites until a reaction front is established. It is followed by the progressive conversion period, in which K+, SO42- and NH4+increase in the solution until reaching stabilization. The reaction was followed by determination of K with AAS. The obtained results are consistent with the kinetic model of constant-size spherical particles and unreacted core with chemical control. Partially decomposed particles were also observed by SEM, where an unreacted arsenojarosite core, a reaction front and an ash halo made of amorphous Fe(OH)3 with adsorbed AsO4 can be seen.

Original languageEnglish
Title of host publicationProceedings - European Metallurgical Conference, EMC 2015
PublisherGDMB Verlag GmbH
Pages523-536
Number of pages14
ISBN (Electronic)9783940276612
StatePublished - 2015
Event8th European Metallurgical Conference, EMC 2015 - Dusseldorf, Germany
Duration: 14 Jun 201517 Jun 2015

Publication series

NameProceedings - European Metallurgical Conference, EMC 2015
Volume1

Conference

Conference8th European Metallurgical Conference, EMC 2015
Country/TerritoryGermany
CityDusseldorf
Period14/06/1517/06/15

Keywords

  • Arsenojarosite
  • Characterization
  • Synthesis

Fingerprint

Dive into the research topics of 'Synthesis and nature of the reaction of a solid solution of ammonium-potassium arsenojarosite in NaOH medium'. Together they form a unique fingerprint.

Cite this