Authors: Palmer, Sara J.; Frost, Ray L.

Source: Applied Spectroscopy, Volume 63, Issue 7, Pages 162A-178A and 727-858 (July 2009) , pp. 748-752(5)

Publisher: Society for Applied Spectroscopy

Abstract:

The seawater neutralization process is currently used in the alumina industry to reduce the pH and dissolved metal concentrations in bauxite refinery residues through the precipitation of Mg, Al, and Ca hydroxide and carbonate minerals. This neutralization method is very similar to the co-precipitation method used to synthesize hydrotalcite (Mg₆Al₂(OH)₁₆CO₃.4H₂O). This study looks at the effect of temperature on the type of precipitates that form from the seawater neutralization process of Bayer liquor. The Bayer precipitates have been characterized by a variety of techniques, including X-ray diffraction (XRD), Raman spectroscopy, and infrared spectroscopy. The mineralogical composition of Bayer precipitates largely includes hydrotalcite, hydromagnesite, and calcium carbonate species. Analysis with XRD determined that Bayer hydrotalcites that are synthesized at 55 °C have a larger interlayer distance, indicating that more anions are removed from Bayer liquor. Vibrational spectroscopic techniques have identified an increase in hydrogen bond strength for precipitates formed at 55 °C, suggesting the formation of a more stable Bayer hydrotalcite. Raman spectroscopy identified the intercalation of sulfate and carbonate anions into Bayer hydrotalcites using these synthesis conditions.

Keywords: HYDROTALCITE; BAYER LIQUOR; CHARACTERIZATION; RAMAN SPECTROSCOPY

Document Type: Research article

DOI: http://dx.doi.org/10.1366/000370209788701152

Affiliations: 1: Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, Queensland, Australia

Publication date: 2009-07-01

More about this publication?

• The Society publishes the internationally recognized, peer reviewed journal, Applied Spectroscopy, which is available both in print and online. Subscriptions are included with membership or can be purchased by institutional or corporate organizations. Abstracts may be viewed free of charge.
  
  Previously published as Bulletin (Society for Applied Spectroscopy)
• Editorial Board
• Information for Authors
• Submit a Paper
• Subscribe to this Title
• Membership Information
• Request copyrighted SAS materials
• Spectroscopic Nomenclature
• Focus Compendium
• ingentaconnect is not responsible for the content or availability of external websites

Related content

• In this: publication
• By this: publisher
• In this Subject: Analytical Chemistry
• By this author: Palmer, Sara J. ;  Frost, Ray L.

Website © Publishing Technology. Article copyright remains with the publisher, society or author(s) as specified within the article.

• Terms and conditions
• Privacy policy
• Information for advertisers