open access

https://hdl.handle.net/2115/50818

Suppression of pyrite oxidation by carrier microencapsulation using Silicon and Catechol

英語

pyrite oxidation

2011-12-07

Taylor & Francis

Mineral Processing and Extractive Metallurgy Review: An International Journal

33(2)

89-98

Acid mine drainage (AMD) is formed from the natural oxidation of sulfide minerals such as pyrite, FeS2. Prevention of acid mine drainage is very important and several techniques are currently being investigated for the treatment and abatement of AMD. This paper proposes carrier-microencapsulation (CME) using Si-catechol complex -Si(cat)3^[2-]- for preventing pyrite oxidation. In CME, the water soluble organic carrier- catechol and metal ion-Si makes a complex e.g., tris-catecholato complex of Si4+, which oxidatively decomposes on pyrite surface and forms a stable oxide or hydroxide e.g., Si(OH)4 or SiO2 layer on the pyrite surface as a protective coating against pyrite oxidation. To demonstrate the effect of CME using Si(cat)3^[2-] on pyrite oxidation, shaking-flask leaching experiments of pyrite without and with CME treatment were performed. Significant halt in pH drop was observed after the CME treatment of pyrite. The CME coating was found very effective even at low Si(cat)3^[2-] concentration of 1 mol m^[-3] and 5 mol m^[-3]. The amount of Fe and S leached were lower from the pyrite with CME treatment, indicating that CME using Si and catechol is effective in suppressing pyrite oxidation. The effect of pH and presence of microorganism were also evaluated. The CME coating was found very effective even in acidic pH range. The CME treatment suppressed pyrite oxidation even in the presence of iron oxidizing microorganism. Presence of Si and O on the residue pyrite surface in SEM-EDX analysis supported the sustainability of CME coating at acidic pH.

学術雑誌論文

Accepted Manuscript

This is an Author's Accepted Manuscript of an article published in Mineral Processing and Extractive Metallurgy Review: An International Journal, 33(2), 07 Dec 2011, pages 89-98, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/08827508.2011.562946.

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