ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Determination of the iron oxide content in bauxite: comparing ICP-OES with UV–VIS and volumetric analysis

Gordana Ostojić, Dragica Lazić, and Saša Zeljković

Alumina Ltd, Zvornik, Bosnia and Herzegovina

E-mail: sasa.zeljkovic@pmf.unibl.org

Received: 1 May 2020  Accepted: 1 August 2020

Abstract:

This study presents the results of the iron oxide content determination in bauxite by means of inductively coupled plasma optical emission spectrometry (ICP-OES), volumetry, and UV–VIS spectrophotometry. Nine certified bauxite reference samples with Fe₂O₃ content from 7.14 to 28.20% were analyzed. Two methods of bauxite sample preparation were applied: melting with a mixture of Na₂CO₃:Na₂B₄O₇ (3:1) and dissolving with a combination of acids (HCl, HNO₃, and H₂SO₄). The recovery value for all the methods used in relation to the certified values was in the range from 92.41% to 113.87%. By using statistical tests, it has been confirmed that the results of ICP-OES analysis generally agree with other methods, which supports its adoption as an alternative for Fe₂O₃ determination in bauxite. Due to a shorter preparation time and complete dissolution, it is recommended to prepare the samples by melting.

Keywords: Iron-oxide; ICP-OES; Volumetry; UV–VIS spectrophotometry; Bauxite

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01305-z

Chemical Papers 75 (1) 389–396 (2021)