Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Effects of mixing proportions and firing temperature on properties of electric porcelain from Ugandan minerals
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Mechanical Metallurgy.
2008 (English)In: Industrial ceramics, ISSN 1121-7588, Vol. 28, no 1, 1-10 p.Article in journal (Refereed) Published
Abstract [en]

Five sample mixtures of Ugandan kaolin, ball clay, feldspar and flint were formulated and porcelain samples fabricated by extrusion through a vacuum pugmill. Samples were evaluated for formability. The degree of densification of sintered specimens fired at 1200 to 1350 degrees C was evaluated by measuring the firing shrinkage, bulk density, water absorption and bending strength. Crystalline phases and mullite morphology were studied using XRD and SEM respectively. Dielectric strength measurements were carried out on disc specimens. Dielectric and bending strength properties deteriorated at high temperatures because of pore formation and decreasing amount of undissolved quartz in the crystalline phase. An optimum composition of 30% kaolin, 15% ball clay, 30% feldspar and 25% quartz yielded an unglazed body with highest bending strength of 72MPa and dielectric strength of 19MVm(-1) after firing at 1250 degrees C. The body consisted of small, closely packed mullite needles and undissolved quartz crystals embedded in a glass matrix.

Place, publisher, year, edition, pages
2008. Vol. 28, no 1, 1-10 p.
Keyword [en]
rice husk ash, whiteware compositions, bending strength, mechanical-behavior, raw-materials, silica fume, fly-ash, quartz, substitution, constitution
National Category
Chemical Engineering
Identifiers
URN: urn:nbn:se:kth:diva-17593ISI: 000256573400001Scopus ID: 2-s2.0-45749156420OAI: oai:DiVA.org:kth-17593DiVA: diva2:335637
Note
QC 20100525Available from: 2010-08-05 Created: 2010-08-05 Last updated: 2017-12-12Bibliographically approved
In thesis
1. Assessment of ceramic raw materials in Uganda for electrical porcelain
Open this publication in new window or tab >>Assessment of ceramic raw materials in Uganda for electrical porcelain
2006 (English)Licentiate thesis, comprehensive summary (Other scientific)
Abstract [en]

Clay, quartz and feldspar are widely available in Uganda. The location and properties of various clay deposits are reported in the literature, but little is reported on feldspar and quartz deposits. In this work an extended literature on ceramics and porcelains in particular, is documented. Samples from two deposits of feldspar and two deposits of quartz are characterised and found to possess requisite properties for making porcelain insulators. Sample porcelain bodies are made from materials collected from selected deposits using different mixing proportions of clay, feldspar and quartz. Their properties in relation to workability, firing temperature, dielectric and bending strengths are studied. It is found that a mixture consisting of 30% Mutaka kaolin, 15% Mukono ball clay, 30% Mutaka feldspar and 25% Lido beach flint yields a body with highest mechanical strength (72MPa) and dielectric strength (19kV/mm) when fired at 1250°C. The strength (both mechanical and dielectric) is found to decrease with increasing firing temperature. At high firing temperatures, the undissolved quartz in the body decreased, the glass content increases and pores are formed. Mullite content on the other hand does not change at temperatures above 1200°C but there are significant differences in the morphologies of the mullite crystals in the samples. Optimum mechanical and electrical properties are found at maximum virtification and a microstructure showing small closely packed mullite needles.

Place, publisher, year, edition, pages
Stockholm: KTH, 2006. ii, 20 p.
Series
KTH/MSE--06/45--SE+MEK/AVH
Keyword
porcelain, characterisation, bending strength, dielectric strength, Uganda
National Category
Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-4013 (URN)91-7178-408-X (ISBN)
Presentation
2006-06-02, Konferensrum K408, KTH, Brinellvägen 23, Stockholm, 10:00
Opponent
Supervisors
Note
QC 20101122Available from: 2006-05-31 Created: 2006-05-31 Last updated: 2010-11-22Bibliographically approved

Open Access in DiVA

No full text

Scopus

Search in DiVA

By author/editor
Olupot, Peter W.Jonsson, Stefan
By organisation
Materials Science and EngineeringMechanical Metallurgy
In the same journal
Industrial ceramics
Chemical Engineering

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 108 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf