Sodalite solids formation at the surface of iron oxide and its impact on flocculation

Sodalite represents the main desilication product (DSP) phase formed from reactive silica during alkaline digestion of bauxite in the Bayer Process. Previous studies into DSP effects on bauxite residue flocculation have focused on flocculant selection or digestion optimisation, not answering a funda...

Full description

Bibliographic Details
Main Authors: Senaputra, A., Fawell, P., Jones, Franca, Smith, P.
Format: Conference Paper
Published: 2013
Online Access:http://hdl.handle.net/20.500.11937/34365
_version_ 1848754202837254144
author Senaputra, A.
Fawell, P.
Jones, Franca
Smith, P.
author_facet Senaputra, A.
Fawell, P.
Jones, Franca
Smith, P.
author_sort Senaputra, A.
building Curtin Institutional Repository
collection Online Access
description Sodalite represents the main desilication product (DSP) phase formed from reactive silica during alkaline digestion of bauxite in the Bayer Process. Previous studies into DSP effects on bauxite residue flocculation have focused on flocculant selection or digestion optimisation, not answering a fundamental question: does DSP coat the residue and thereby change surface properties? This study sought to answer that question by contrasting the physicochemical properties of hematite slurries (as a model phase for residue) containing DSP where it was either made in-situ or added as a physical mixture. On the basis of differences found in dewatering behaviour, zeta potential, desilication rates and microscopy of the solids, it is proposed that DSP nuclei initially associate with the hematite surface and subsequently affect flocculant adsorption chemistry, resulting in different extents of flocculant adsorption and smaller aggregates. The practical implications for flocculation processes are discussed.
first_indexed 2025-11-14T08:36:40Z
format Conference Paper
id curtin-20.500.11937-34365
institution Curtin University Malaysia
institution_category Local University
last_indexed 2025-11-14T08:36:40Z
publishDate 2013
recordtype eprints
repository_type Digital Repository
spelling curtin-20.500.11937-343652017-01-30T13:43:00Z Sodalite solids formation at the surface of iron oxide and its impact on flocculation Senaputra, A. Fawell, P. Jones, Franca Smith, P. Sodalite represents the main desilication product (DSP) phase formed from reactive silica during alkaline digestion of bauxite in the Bayer Process. Previous studies into DSP effects on bauxite residue flocculation have focused on flocculant selection or digestion optimisation, not answering a fundamental question: does DSP coat the residue and thereby change surface properties? This study sought to answer that question by contrasting the physicochemical properties of hematite slurries (as a model phase for residue) containing DSP where it was either made in-situ or added as a physical mixture. On the basis of differences found in dewatering behaviour, zeta potential, desilication rates and microscopy of the solids, it is proposed that DSP nuclei initially associate with the hematite surface and subsequently affect flocculant adsorption chemistry, resulting in different extents of flocculant adsorption and smaller aggregates. The practical implications for flocculation processes are discussed. 2013 Conference Paper http://hdl.handle.net/20.500.11937/34365 restricted
spellingShingle Senaputra, A.
Fawell, P.
Jones, Franca
Smith, P.
Sodalite solids formation at the surface of iron oxide and its impact on flocculation
title Sodalite solids formation at the surface of iron oxide and its impact on flocculation
title_full Sodalite solids formation at the surface of iron oxide and its impact on flocculation
title_fullStr Sodalite solids formation at the surface of iron oxide and its impact on flocculation
title_full_unstemmed Sodalite solids formation at the surface of iron oxide and its impact on flocculation
title_short Sodalite solids formation at the surface of iron oxide and its impact on flocculation
title_sort sodalite solids formation at the surface of iron oxide and its impact on flocculation
url http://hdl.handle.net/20.500.11937/34365