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In the aluminum industries, there are several steps involved in processing since the extraction of bauxite to obtain the final product (Al). During the development of these, various steps generated wastes. One of them, from the electrostatic filter of the calcination step of the Bayer process is a very fine black powder, rich in alumina (Al2O3) that does not meet industry specifications, and it is discarded in the industry yard. Alumina is a noble material and has high commercial value. This black powder has great prospects for recovery, recycling, and future applications. Therefore, it is important to perform characterization of tailings and to do that we have used XRD, SEM, EDS, FTIR, Raman, and thermal analysis.

Calcium carbonate (CaCO3) is a filler often utilized by the Brazilian mattress factories in the production of polyurethane foams. The filler allows the substitution of part of the polymeric agents, conferring dimensional stability and hardness to the foams. However, in agreement with experimental data, it is observed that the excess of commercial CaCO3 utilized in industry causes the increase of hysteresis, possibly causing permanent deformations and damaging the quality of the final product. In the present work, the physico-chemical analyses of the flexible polyurethane foams with different contents of CaCO3 were performed. The foams are submitted to the morphological, mechanical and positron analyses to verify the alterations provoked by the progressive introduction of this filler.

Uma das cargas mais utilizadas na fabricação de espumas flexíveis de poliuretano é o carbonato de cálcio (CaCO3) por ser não abrasivo, não tóxico e de fácil pigmentação. Contudo, é observado que o excesso de CaCO3 comercial usado nas indústrias causa deformações permanentes, o que prejudica a qualidade do produto final. No presente trabalho é proposto o estudo do efeito da concentração de CaCO3 comercial na fabricação de espumas flexíveis de poliuretano. Foram utilizadas diferentes concentrações de CaCO3 na síntese das espumas, as quais foram submetidas à análises térmica e morfológica, afim de verificar as alterações provocadas pela introdução progressiva da carga. One filler often utilized in flexible polyurethane foams is calcium carbonate (CaCO3) because it is non-abrasiveness, non-toxicity and facilitated pigmentation. However, it is observed that the excess of commercial CaCO3 utilized in industry possibly causing permanent deformations and damaging the quality of the final product. The effect of different concentrations of commercial CaCO3, in flexible foams, was studied. Different concentrations of CaCO3 were used for the synthesis of flexible polyurethane foams, which were submitted to morphological and thermal analyses to verify the alterations provoked by the progressive introduction of this filler.