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EFFECT OF ADDING ALUNITE TO REFRACTORY CLAYS
Author(s) -
Knížek Jan O.,
Fetter Hans
Publication year - 1946
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1946.tb11609.x
Subject(s) - alunite , softening , materials science , aluminosilicate , refractory (planetary science) , mineralogy , composite material , andesite , sulfur , metallurgy , shrinkage , geology , chemistry , geochemistry , volcano , biochemistry , seismology , volcanic rock , hydrothermal circulation , catalysis
A bstract Four grades of alunite ore were mixed with four grades of fire clays, and the mixtures were formed into modulus of rupture test bars. These were fired to cone 13–14. Specimens were tested for bulk density and modulus of rupture after the initial firing and after reheating to 1400°C. and 1600°C. Softening temperatures of the mixtures were also determined. In general, small quantities (not exceeding 20%) of alunites improved fired characteristics, including decreasing the reheat shrinkage and increasing the P.C.E. The purity of both raw materials was the determining factor. Excessive additions of alunite, particularly to the low‐grade clays, caused bloating as a result of the evolution of sulfur gases from the alunite.