Advertisement
Published in:
2016 | OriginalPaper | Chapter
Alkaline Reactivity of Solid Solution of NH4-Na Jarosite with Arsenic
Authors : Víctor Flores, Francisco Patiño, Elia Palacios, Iván Reyes, Mizraim Flores, Martin Reyes, Julio Juárez
Published in: TMS 2015 144th Annual Meeting & Exhibition
Publisher: Springer International Publishing
Activate our intelligent search to find suitable subject content or patents.
Select sections of text to find matching patents with Artificial Intelligence. powered by
Select sections of text to find additional relevant content using AI-assisted search. powered by
In this work, a kinetic analysis of the decomposition process of a solid solution of ammonium and sodium jarosite with arsenic incorporated into its structure in NaOH medium is presented. Atomic absorption spectroscopy (AAS), inductively coupled plasma optical emission spectroscopy (ICP-OES), elemental analysis and X-ray diffraction (XRD) were used for the characterization of the solid solution and the decomposition products. According to the results, the approximate stoichiometry of the jarosite synthesized is as follows: [(NH4)0.72Na0.06(H3O)0.21]Fe3 2.52(SO4)1.85(AsO4)0.15[(OH)4.41(H2O)1.59].It was found that the alkaline decomposition reaction proceeds through an induction period (equation 1), followed by a progressive conversion period (equation 2). (1)<math display='block'> <munder> <mo>−</mo> <mi>θ</mi> </munder> <mo>=</mo><mfrac> <mrow> <msub> <mi>r</mi> <mn>0</mn> </msub> </mrow> <mrow> <msub> <mi>V</mi> <mi>m</mi> </msub> </mrow> </mfrac> <mo>⋅</mo><mn>9.7684</mn><mo>×</mo><msup> <mn>10</mn> <mrow> <mn>10</mn> </mrow> </msup> <mo>⋅</mo><msup> <mi>e</mi> <mrow> <mo>−</mo><mn>65</mn><mo>,</mo><mn>030</mn><mo>/</mo><mi>R</mi><mi>T</mi> </mrow> </msup> <msup> <mrow><mo>[</mo> <mrow> <mi>O</mi><msup> <mi>H</mi> <mo>−</mo> </msup> </mrow> <mo>]</mo></mrow> <mrow> <mn>.22</mn> </mrow> </msup> </math>$$\mathop - \limits_\theta = \frac{{{r_0}}}{{{V_m}}} \cdot 9.7684 \times {10^{10}} \cdot {e^{ - 65,030/RT}}{\left[ {O{H^ - }} \right]^{.22}} $$(2)<math display='block'> <mn>1</mn><mo>−</mo><msup> <mrow><mo>(</mo> <mrow> <mn>1</mn><mo>−</mo><mi>X</mi> </mrow> <mo>)</mo></mrow> <mrow> <mn>1</mn><mo>/</mo><mn>3</mn> </mrow> </msup> <mo>=</mo><mn>3.4395</mn><mo>×</mo><msup> <mn>10</mn> <mn>6</mn> </msup> <mo>⋅</mo><msup> <mi>e</mi> <mrow> <mo>−</mo><mn>51</mn><mo>,</mo><mn>580</mn><mo>/</mo><mi>R</mi><mi>T</mi> </mrow> </msup> <msup> <mrow><mo>[</mo> <mrow> <mi>O</mi><msup> <mi>H</mi> <mo>−</mo> </msup> </mrow> <mo>]</mo></mrow> <mrow> <mn>0.94</mn> </mrow> </msup> <mi>t</mi> </math> $$1 - {\left( {1 - X} \right)^{1/3}} = 3.4395 \times {10^6} \cdot {e^{ - 51,580/RT}}{\left[ {O{H^ - }} \right]^{0.94}}t $$