Aplicabilidade econômica e técnica de concreto refratário em calcinadores de alumina em indústria de São Luís

Abstract

The objective of this work is to discuss the use of refractory concretes in the internal coating of alumina calciners, as well as the main wastes to which they are subjected. This paper also shows a comparative study between Australian refractory concrete and a nationally produced refractory concrete, both applied in a factory in the city of São Luís/MA, with the objective to compare the performance of national and imported refractory materials. The replacement of the refractory concrete currently in use (imported), based on Andalusite, is justified by the high wear presented in the panels located on the warmer region of the calciner and in that way, one of the materials evaluated as possible substitutes was a refractory concrete with colloidal silica binder manufactured nationally. The methodology that was used in this study was based on the achievement of some initial bibliographical researches and on the information collected in the field with a company specialized on applying this type of concrete, so that in the end it would be possible to evaluate if the performance of the new material was more satisfactory than the previously applied one. Despite the fact that the nationally produced material presents good properties, the results were not totally satisfactory, which can indicate poor thermal insulation of the dense and insulated concrete or even a wear on the thickness of the material, which, if remained in an evident way, will make it impossible the use of this material. However, conclusive analyzes can only be taken during the next calcinator inspection, where refractory concrete manufactured in Brazil was applied for testing, where the actual wear of the material could be seen, understanding the reasons for the results found in the study