Estudo da viabilidade do uso de mat?rias de baixo valor econ?mico do Quadril?tero Ferr?fero na fabrica??o de materiais cer?micos.

Programa de P?s-Gradua??o em Evolu??o Crustal e Recursos Naturais. Departamento de Geologia. Escola de Minas, Universidade Federal de Ouro Preto.Estudos pr?vios sobre a g?nese dos dep?sitos argilosos cenoz?icos do Quadril?tero Ferr?fero foram fundamentais para a sele??o das f?cies mais argilosas em tr?s ocorr?ncias dessa regi?o e para o estudo da viabilidade da sua aplica??o tecnol?gica em cer?mica vermelha, tal como na fabrica??o de tijolos comuns obtidos a altas temperaturas, visando sua utiliza??o como material de constru??o, e na fabrica??o de geopol?meros obtidos a baixa temperatura, tamb?m para sua utiliza??o como material de constru??o e como material filtrante de ?guas polu?das. As mat?rias-primas empregadas nessa pesquisa foram as argilas caulin?ticas das f?cies arenito coesivo maci?o (ACM), diamictito branco (DB) e diamictito vermelho (DV), do dep?sito de Padre Domingos, localizado no sinclinal Moeda; das f?cies argilosa fri?vel (FS) e argilosa maci?a (AM), do dep?sito Morro do Caxambu, localizado no sinclinal Dom Bosco e; das f?cies R1 e R5, localizadas em cortes da rodovia BR-356. Como aditivos foram usados filito (F), que ? o embasamento dos dep?sitos argilosos, e quartzito (Q), proveniente de rejeitos da fabrica??o de placas de revestimento, localizados na cidade de Ouro Preto. Adicionalmente na elabora??o de geopol?meros foi tamb?m utilizada lama vermelha (LMV) proveniente de res?duos da ind?stria de alum?nio, da regi?o de Po?os de Caldas, Minas Gerais. Foram coletados 10 kg de amostra em cada uma das f?cies selecionadas. As amostras foram secadas, destorroadas, homogeneizadas, quarteadas, mo?das e peneiradas a 35 mesh (0,425 mm). Seguidamente, an?lises granulom?tricas, difra??o de raios-X (DRX), fluoresc?ncia de raios-X (FRX), an?lises termodiferenciais (ATD) e termogravim?tricas (ATG), plasticidade, densidade, superf?cie especifica, porosidade, microscopia eletr?nica de varredura (MEV) permitiram confirmar a predomin?ncia da caulinita e, secundariamente, quartzo, hematita, feldspato, muscovita e goethita, al?m de conhecer detalhadamente outras caracter?sticas f?sicas, qu?mica e texturais das argilas. As cores apresentadas pelas amostras est?o diretamente relacionadas ao conte?do em Fe2O3. Ap?s ajustar a umidade ? 8,5 % corpos de prova foram confeccionados e queimados a 900 e a 1.100 ?C. Os corpos cer?micos obtidos com as amostras DV e R1 resultaram com superf?cies homog?neas e sem fraturas, atingindo valores apropriados de absor??o de ?gua, retra??o linear e de resist?ncia ? compress?o ?s normas t?cnicas para tijolos para alvenaria. As cinco amostras restantes (ACM, DB, FS, AM e R5) foram testadas com o aditivo filito (F), em diferentes propor??es. Somente as misturas ACM+15F, DB+5F, FS+5F, AM+5F e, R5+5F ap?s queimadas a 900 ?C resultaram em corpos com caracter?sticas f?sicas e mec?nicas adequadas ? ind?stria de cer?mica vermelha. Ensaios adicionais com uma solu??o alcalina (12 mol/L NaOH) resultaram no aumento da resist?ncia mec?nica e na redu??o da absor??o de ?gua dos corpos. Para a obten??o de geopol?meros, rejeitos de quartzito (Q), tr?s amostras das argilas caulin?ticas (DB, R1 e R5) e lama vermelha (LMV), foram misturados adequadamente nas propor??es: 34%Q_66%R5; 33%Q_67%DB; 49%R1_51%R5; 48%R1_52%DB; 34%Q_56%DB_10%LMV e 34%Q_46%DB_20% LMV. Adicionalmente, geopol?meros tamb?m foram obtidos com as amostras R1 e ACM misturadas com lama vermelha (LMV) na propor??o de 50%R1_40%ACM_10%LMV. Todos os geopol?meros obtidos mostraram superf?cies homog?neas e sem fraturas, com valores de resist?ncia mec?nica superiores aos estipulados para sua utiliza??o como tijolo para alvenaria. A mineralogia dos produtos obtidos indicou a forma??o de sodalita e ze?lita, que s?o esp?cies comuns nos geopol?meros. Finalmente, pesquisando novas aplica??es, ensaios de filtragem utilizando os geopol?meros como filtros de ?guas ?cidas contendo metais pesados mostraram a viabilidade do seu uso na obten??o de ?guas alcalinas e/ou ligeiramente ?cidas e com uma importante redu??o do conte?do de metais pesados. Os resultados desta pesquisa permitiram valorizar mat?rias-primas para o seu uso na ind?stria de cer?mica vermelha, al?m de oferecer um destino final ambientamente correto tanto para o quartzito quanto para a lama vermelha, que atualmente s?o fontes geradoras de poluentes ambientais.Previous studies on Cenozoic clay deposits of the Quadril?tero Ferr?fero were essential to the selection of the most clayey facies in three occurrences of this region and to study the feasibility of technological application in red ceramic, such as in the fabrication of common bricks obtained at high temperatures, for their use as construction material, and in the fabrication of geopolymers obtained at low temperature, for their use as construction material and as filter material for polluted water. The raw materials used in this research were the kaolinitic clay of massive cohesive sandstone (ACM), white diamictite (DB) and red diamictite (DV) facies, of the Padre Domingos deposit, located in the Moeda syncline; of friable clayey (FS) and massive clayey (AM) facies of Morro do Caxambu deposit, located in the syncline Dom Bosco and; the R1 and R5 facies, located in BR-356 highway cuts. As additives were used phyllite (F), which is the basement of clay deposits, and quartzite (Q), from wastes of fabrication of coating plates, located in Ouro Preto city. Additionally in the fabrication of geopolymers was also used red mud (LMV) from waste of the aluminum industry, from Po?os de Caldas region, Minas Gerais. Was collected 10 kg sample of each one of the selected facies. The samples were dried, disaggregated, homogenized, reduced, milling and sieved to 35 mesh (0.425 mm). Next, granulometric analyses, X-ray diffraction (XRD), X-ray fluorescence (XRF), thermodifferential (DTA) and thermogravimetric (TGA) analysis, plasticity, density, surface area, porosity, scanning electron microscopy (SEM) allowed to confirm the predominance of kaolinite and secondarily, quartz, hematite, feldspar, muscovite and goethite, as well as know in detail other physical, chemical and textural characteristics of clays. The colors in the samples are directly associated to the content of Fe2O3. After adjusted the humidity to 8.5% the samples were prepared and fired at 900 and 1,100 ?C. The ceramic samples with DV and R1 resulted with homogeneous surfaces and without fractures, reaching appropriate values of water absorption, linear shrinkage and compressive resistance to technical standards for brick masonry. The remaining five samples (ACM, DB, FS, AM and R5) were tested with the additive phyllite (F), in different proportions. Only the blends ACM + 15F, DB + 5F, FS + 5F, AM + 5F and R5 + 5F after burning at 900 ?C resulted in bodies with physical and mechanical properties appropriated to the ceramic industry. Additional tests with an alkaline solution (12 mol / L NaOH) resulted in a increase of the mechanical strength and reduction of water absorption from the bodies. To obtain geopolymers, quartzite tailings (Q) of three samples of kaolinitic clay (DB, R1 and R5) and red mud (LMV) were adequately mixed in the proportions: 34%Q_66%R5; 33%Q_67%DB; 49%R1_51%R5; 48%R1_52%DB; 34%Q_56%DB_10%LMV and 34%Q_46%DB_20%LMV. Additionally, geopolymers were also obtained samples with the R1 and ACM mixed with red mud (LMV) in the proportion of 50%R1_40%ACM_10% LMV. All geopolymers showed homogeneous surfaces and without fractures, with strength values higher than those required for use as brick masonry. The mineralogy of the products obtained indicated the formation of sodalite and zeolite species which are common in geopolymers. Finally, searching for new applications, filtration assays using the geopolymers as a filter for acidic water containing heavy metals shown the feasibility of their use in obtaining alkaline and/or slightly acidic water, with a significant reduction in heavy metal content. The results of these research allowed evaluate raw materials for use in the ceramic industry and offer a final destination environmentally correctly for both quartzite and the red mud, which are currently sources of environmental pollutants