Hydrotalcite formation for contaminant removal from ranger mine process water

G. B. Douglas, L. A. Wendling, R. Pleysier, M. G. Trefry

Research output: Contribution to journalArticleScientificpeer-review

32 Citations (Scopus)

Abstract

Process water from the Ranger Uranium Mine requires treatment to meet stringent environmental water quality criteria. The acidic water contains substantial SO4, metals, and U. One novel treatment method under consideration is the use of Na-aluminate to both neutralise the process water and precipitate hydrotalcites. Hydrotalcites are a class of Mg-Al layered double hydroxide minerals with a typical endmember chemical composition: Mg6Al2(A)(OH)16·n(H2O), where A = CO32-, SO42-, etc. Many acidic wastewaters contain Mg and/or Al in sufficient abundance for hydrotalcite formation upon addition of alkali to achieve solution pH > 5, and Mg and/or Al to attain a Mg:Al ratio of 2 to 3:1. The utility of hydrotalcites lies in their ability to incorporate a range of cationic (Cu2+, UO22+), metalloid (AsO43-), and (oxy)anionic contaminants (CrO42-). The broad spectrum removal of contaminants, including U, also indicates that hydrotalcites and their derivatives could potentially be used as a containment material in nuclear waste repositories. In this study, Ranger process water derived from extraction of U from chloritic schist was treated with Na-aluminate sourced from Bayer process liquor, in combination with NaOH or Ca(OH)2. Hydrotalcites formed as the primary mineral during process water neutralisation with the ability to simultaneously remove a suite of contaminants from solution.

Original languageEnglish
Pages (from-to)108-115
JournalMine Water and the Environment
Volume29
Issue number2
DOIs
Publication statusPublished - 18 Jun 2010
MoE publication typeA1 Journal article-refereed

Keywords

  • Hydrotalcite
  • Uranium
  • Wastewater

Fingerprint Dive into the research topics of 'Hydrotalcite formation for contaminant removal from ranger mine process water'. Together they form a unique fingerprint.

Cite this