Caracterização física e química de argilas localizadas na área da empresa Mineração do Nordeste

Abstract

Knowledge of the properties of clays is essential for their destination for a suitable application. The objective of this work was to carry out the physical and chemical characterization of clays present in the iron mining of the company Mineração do Nordeste located in the municipality of Sobral. The collected material was analyzed in order to determine the physical and chemical characteristics by means of X-ray fluorescence, granulometry, consistency and density indices. The results X-ray fluorescence tests showed that the percentage of SiO2 varies from 29.2 to 63.1%, whereas the content of Al2O3 varies from 10.1 to 20.6%, and the percentage of Fe2O3 varies from 13.2 to 46.5%. For the granulometry tests, the percentage of clay varies from 5.3% to 49.5%, with the highest value obtained in sample 1. Samples 2, 3 and 5 present a high value of the gravel fraction (42.6 %, 49.1% and 37.2%, respectively), whereas in sample 4 the silt fraction predominates (25%). Using the granulometric composition together with the Winkler diagram, it was shown that only sample 4 is within the usable region for application in red ceramic. In consistency index tests, it was observed that samples 2, 3 and 5 are considered moderately plastic with IP values of 12.5%, 11% and 14%, while samples 1 and 4 are classified as highly plastics, presenting IP of 30.5% and 20.5%, meeting the criteria for application as raw material in the red ceramic industry. Density values ranged from 2.32 g/cm3 to 2.76 g/cm3. The samples show possible applications such as: aggregates in civil construction, drilling fluid, manufacture of clay pots and raw material for nanocomposites, but there is a need for a more detailed study to prove the application.