Estudo da obtenção de zeólitas a partir de materiais residuais: caulim residual, lama vermelha e casaca de arroz

Abstract

The Amazon region has the largest kaolin reserves and bauxite in Brazil, with the majority located in the region of Pará state. In the beneficiation process of this mining are generated large quantities of mineral waste, which are difficult to sedimentation hinders forest recovery area, thereby creating an environmental problem. Red mud is the residue generated by the aluminum industry. Like other industrial waste and handling complex presents difficulties, and besides being a hazardous material by low grain size and alkalinity. On the other, rice husk ash is an agro-industrial waste resulting from the burning process of the rice home and has a high percentage of silica (SiO2) in its constitution. In zeolite synthesis processes, the search for alternative sources of silicon and aluminum continues to encourage research. In this sense, this paper proposes to obtain adsorbent materials from natural raw materials found in abundance in the region, such as kaolin and red mud as a source of silica and aluminum and silica and rice husk. The zeolite synthesis has the intention and purpose of the aggregate value stop these materials. Kaolin Amazon has proved a good sustainable solution for the synthesis thereof, and looking for the same success with the red mud and rice home, where both experienced a thermochemical treatment with sulfuric acid (mud-red) and the hydrochloric acid (rice hull ash). These were tested in hydrothermal synthesis of zeolite in calcined form (400 and 800°C) at a time four hours with NaOH (3.5 M) to 100°C for autogenous pressure, for 17, 24 and 48 h in order to take advantage of the aluminum-red mud, rice husk silica, besides of aluminum silicon kaolinite.