Licenciatura em Química (Sede)
URI permanente desta comunidadehttps://arandu.ufrpe.br/handle/123456789/26
Siglas das Coleções:
APP - Artigo Publicado em Periódico
TAE - Trabalho Apresentado em Evento
TCC - Trabalho de Conclusão de Curso
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Resultados da Pesquisa
Item Estudo de viabilidade do uso de areia residual da produção de silicato de sódio no processo produtivo(2024-09-23) Abreu, Giovanna Pereira de; Gomes, Maria José de Filgueiras; http://lattes.cnpq.br/0060810526769648; http://lattes.cnpq.br/7823109121355746Sand is the main raw material used in the production of sodium silicate. However, the sand waste generated by the silicate industries is a constant and significant problem, with an average annual disposal of 142 tons. Therefore, it is necessary to promote the reduction of this waste through available practices for proper disposal or, when possible, reuse it, given that it can cause negative impacts on the environment. In addition, reusing sand also has the benefit of reducing production costs, since it can be reincluded in the process without compromising yield. In this sense, it is of great relevance to create sustainable solutions capable of efficiently addressing the social, environmental and economic challenges involved and which can be applied in industries. The aim of this work was to evaluate the reuse of this industrial waste and study its reuse in new reactions aimed at the production of sodium silicate. For this purpose, the residue was subjected to a washing process, followed by titrimetric tests, in triplicate, to determine the Na₂O content in the water washing, using 2.0N HCl as titrant, resulting in an average value of 12.80%. X-ray fluorescence tests were also performed on the solid part after washing, indicating a SiO₂ percentage of 99.009%, a value comparable to that of virgin sand, whose SiO₂ content varies between 98.00% and 100.00%, which demonstrates that the results obtained in the residue presented satisfactory results. Based on a formulation suggested in this research, it can be concluded that the reuse of sand in the sodium silicate production process could promote a cost reduction of R$9,870 per batch, representing an annual saving of R$259.670,4, integrating sustainable practices and cost reduction in silicate production.Item Estudos de pré-concentração de platina explorando materiais de sílica organofuncionalizados(2022-10-13) Sousa, Filipe Carvalho Pires de; Belian, Mônica Freire; Lavorante, André Fernando; http://lattes.cnpq.br/1011018535020717; http://lattes.cnpq.br/2626644337183959; http://lattes.cnpq.br/8810636055275824The present work aims to develop an organofunctionalized material through a silylation reaction, by a heterogeneous route, using the Stöber method, capable of effectively coordinating platinum íons (Pt4+). The synthesis of modified silica was carried out by the sol-gel process, where functionalization was carried out one pot through the addition of N´-[(trimethoxysilyl)propylethylenetriamine, tetraethylorthosilicate (TEOS) and ammonium hydroxide, the latter being a catalyst for hydrolysis and condensation reactions. The adsorptive/coordinative capacity of the organofunctionalized silica was evaluated through Fourier transform infrared (FTIR) and electronic absorption techniques. Through infrared spectroscopy, it was possible to observe the presence of bands referring to silanol groups (Si-OH) between 3470 and 3090 cm- 1, and an intense broad band related to siloxane groups (Si-O-Si) at 1029 cm-1. In addition, it was possible to identify bands at 2904 and 2829 cm-1 referring to the N-H groups of the amines present in the organofunctionalization of silica, coming from N´-[(trimethoxysilyl)propylethylenetriamide, as expected; and, at 1465 cm-1, the C-N band of amines is observed. Fourier transform Infrared spectroscopy (FITR) was used as a proposal to observe, through the spectra, the possible changes that occurred with the organofunctionalized compound after reacting with a 10-4 mol L-1 potassium hexachloroplatinate solution. It was possible to observe the shift to lower wave numbers of the signals referring to the N-H and C-N bands, suggesting that the interaction between Pt4+ ions and the silica material is predominantly through coordinative bonds between the ion and the amino groups. After the studies in the infrared region, test were performed on the electronic absorption of platinum ions with different concentrations, and then an analytical curve was constructed. However, two analytical curves were performed in order to quantitatively analyze the adsorption of platinum ions on silica materials. The first with concentrations of 10-3, 10-4, 10-5, 10-6 mol L-1 resulted in a good linear regression coefficient of 0,9995. At lower concentrations, at values of 12,2, 48,8, 97,5, and 195 ppm, the linear regression was also satisfactory, but with a value of 0,9801. Thus, the synthesized compound SIL-TMSDT proved to be effective for platinum (Pt4+) adsorption and efficiency pre-concentration.