Development of a mixing device for red mud flocculants.

The performance of flocculants used in the solid-liquid separation of red mud is often compromised by the methods used to mix the fast acting polymers into the slurry. A simple model of the relationship between flocculant performance and intensity of mixing is proposed and a device for mixing floccu...

Full description

Bibliographic Details
Main Author: Dougherty, David J.
Format: Thesis
Language:English
Published: Curtin University 1999
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/2083
_version_ 1848743854016036864
author Dougherty, David J.
author_facet Dougherty, David J.
author_sort Dougherty, David J.
building Curtin Institutional Repository
collection Online Access
description The performance of flocculants used in the solid-liquid separation of red mud is often compromised by the methods used to mix the fast acting polymers into the slurry. A simple model of the relationship between flocculant performance and intensity of mixing is proposed and a device for mixing flocculant and slurry has been developed on the basis of the model.The intensity of mixing at the point of distributing the flocculant into the slurry is arguably the most important variable influencing the final flocculant performance. This relationship is established using data from flocculation tests in an agitated tank. The flocculant performance is monitored using an optical sensor and the settling rate of the solid-liquid interface is used as a comparison for the optical sensor. The difficulties, errors and merits of the optical sensor to study the flocculation of red mud and automatic control of flocculation processes are also assessed.The mixing device is connected to a pipe for flocculation tests with red mud. For the tests carried out, a high level of flocculation was recorded.The mixing device combines the flocculant and slurry as thin annular jets directed into one another. The opening for the slurry jet can be altered to provide a variation of the mixing that is achieved. The capability of the device to mix rapidly has been assessed using the diazo coupling reactions between l-naphthol and diazotised sulphanilic acid in alkaline, aqueous solution at room temperature. Variables studied included flow rate and slurry jet opening. Better mixing was indicated at higher flow rates and at reduced jet opening. The use of the diazo coupling reactions for studying micromixing is also assessed.
first_indexed 2025-11-14T05:52:11Z
format Thesis
id curtin-20.500.11937-2083
institution Curtin University Malaysia
institution_category Local University
language English
last_indexed 2025-11-14T05:52:11Z
publishDate 1999
publisher Curtin University
recordtype eprints
repository_type Digital Repository
spelling curtin-20.500.11937-20832019-03-27T01:31:30Z Development of a mixing device for red mud flocculants. Dougherty, David J. red mud flocculants flocculant performance mixing device The performance of flocculants used in the solid-liquid separation of red mud is often compromised by the methods used to mix the fast acting polymers into the slurry. A simple model of the relationship between flocculant performance and intensity of mixing is proposed and a device for mixing flocculant and slurry has been developed on the basis of the model.The intensity of mixing at the point of distributing the flocculant into the slurry is arguably the most important variable influencing the final flocculant performance. This relationship is established using data from flocculation tests in an agitated tank. The flocculant performance is monitored using an optical sensor and the settling rate of the solid-liquid interface is used as a comparison for the optical sensor. The difficulties, errors and merits of the optical sensor to study the flocculation of red mud and automatic control of flocculation processes are also assessed.The mixing device is connected to a pipe for flocculation tests with red mud. For the tests carried out, a high level of flocculation was recorded.The mixing device combines the flocculant and slurry as thin annular jets directed into one another. The opening for the slurry jet can be altered to provide a variation of the mixing that is achieved. The capability of the device to mix rapidly has been assessed using the diazo coupling reactions between l-naphthol and diazotised sulphanilic acid in alkaline, aqueous solution at room temperature. Variables studied included flow rate and slurry jet opening. Better mixing was indicated at higher flow rates and at reduced jet opening. The use of the diazo coupling reactions for studying micromixing is also assessed. 1999 Thesis http://hdl.handle.net/20.500.11937/2083 en Curtin University fulltext
spellingShingle red mud flocculants
flocculant performance
mixing device
Dougherty, David J.
Development of a mixing device for red mud flocculants.
title Development of a mixing device for red mud flocculants.
title_full Development of a mixing device for red mud flocculants.
title_fullStr Development of a mixing device for red mud flocculants.
title_full_unstemmed Development of a mixing device for red mud flocculants.
title_short Development of a mixing device for red mud flocculants.
title_sort development of a mixing device for red mud flocculants.
topic red mud flocculants
flocculant performance
mixing device
url http://hdl.handle.net/20.500.11937/2083