Properties dependence of chromia and alumina-chromia-zirconia-silica refractories with a mass fraction of 30 % Cr2O3 on the type of chromium oxide

Abstract

In JSC “URIR named after A. S. Berezhnoy” chromia refractories for the lining of pool and feeder of glass-making furnaces for the production of glass fiber from E glass, which are in contact with the glass melt, and alumina-chromia-zirconia-silica refractories with 30 % Cr2O3 for service in the topsides of these furnaces, in areas affected by components of the glass batch and glass melt, have been developed and manufactured. The main raw material for the chromia products manufacturing is metallurgical chromium oxide. In the manufacture of alumina-chromia-zirconia-silica products, metallurgical chromium oxide or a mixture of metallurgical and pigment chromium oxide in a ratio of 2 : 1 is used as the chromium oxide component of the batch. The testing of new materials, such as a new grade of chromium oxide, in the technologies of chromia and alumina-chromia-zirconia-silica refractories is relevant.
 The effect of a new grade of chromium oxide on the properties of chromia refractories has been investigated. It was found that samples of a new grade of chromium oxide, pressed at optimal values of moisture content of the mass and specific pressing pressure, are characterized by a low apparent density of the raw material in comparison with samples made of metallurgical chromium oxide. After firing, samples from chromium oxide of the new grade are not inferior to those of metallurgical chromium oxide in terms of properties, but they have large changes in linear dimensions during firing, which can lead to the formation of cracks, therefore, the issue of obtaining chromia products from mixtures with the replacement of metallurgical chromium oxide with chromium oxide of the new grade in order to increase the apparent density of products requires additional research.
 A study on the effect of new grade of chromium oxide on the properties of alumina-chromia-zirconia-silica refractories with a content of 30 % Cr2O3 has been carried out. It was established that, in the batch for the manufacture of these refractories, containing metallurgical and pigment chromium oxide, it is possible to completely replace the pigment chromium oxide with chromium oxide of the new grade or to increase the content in the batch of chromium oxide of the new grade instead of a part of metallurgical chromium oxide to the ratio of metallurgical chromium oxide and chromium oxide of the new grade 1 : 2.