Influência de diversos aditivos na área específica de argilas esmectíticas, cauliníticas e plásticas para cerâmica branca.

Abstract

The surface area of clay is a fundamental factor in many technological process, such as flocculation and deflocculation, ionic exchange and slip -casting. It is also important for pulverized solids, for example, as in the milling process of mixture, plastic conformation, sintering beyond soil mechanics. Thus, it is undeniable the importance of the present research which is aimed in search of the effects of the use of different additives upon specific area of clays. Eleven natural and industrialized samples ( smectites, kaolins and ball clays for whiteware) were studied with and without additives. Initially the sample passed in sieve ABNT n°- 200 before and after to be treated with additives. The mixture clay-additive was cured in a humid chamber at 100% UR and ambient temperature during a period of seven days. Following the system clay-additive was submitted to the tests of specific area by the methods of Blaine permeameter and adsorption of methylene blue. The results obtained show that the majority of the variabilities occur with the method of adsorption of methylene blue, being the smectites, the clays that exhibit the greater number of variations of specific area and the ball clays the smaller variations in function of the increase of the percentage of the additives.