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    Uso potencial de resíduos da indústria do alumínio na produção de geopolímeros
    (Universidade Federal de São Paulo, 2018-04-27) Almeida, Thelma Miranda de [UNIFESP]; Shinzato, Mirian Chieko [UNIFESP]; Silva, Cecília Chaves Guedes e; Universidade Federal de São Paulo (UNIFESP)
    The aim of this work was to evaluate the aluminum industry waste (red mud and residue from aluminum recycling process) as a source of alumina in production of geopolymers. Geopolymers are formed by amorphous aluminosilicates ligands that can be synthesized at room temperature. The precursor materials used in the production of geopolymers were metakaolinite and volcanic glass. All materials had their chemical composition (x-ray fluorescence), crystalline phases (x-ray diffractometry) and functional groups (infrared spectroscopy with Fourier transform) characterized. Then they were tested in pure form and mixed to produce geopolymers, using sodium silicate alkaline solution. In these tests a series of geopolymer was maintained at 60oC in the first 24 h and at room temperature until completed the respective curing times of 7, 28 and 60 days. Other series remained at room temperature since the beginning of the same curing times. At the end of each period of cure, the geopolymer samples were subjected to compressive strength test and were again characterized. It was observed, in general, that the mechanical strength of the geopolymers increased with the curing time and that the rising of the temperature did not increase this property. All geopolymers prepared with metakaolinite presented a higher compressive strength than those prepared with volcanic glass, due to the SiO2:Al2O3 ratio. The addition of red mud mixed with both precursor materials presented best result of compressive strength that those prepared with the aluminum recycling waste. This is due to the presence of crystalline phases resistant to alkaline attack.