EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
Notícias
A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
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2 resultados
Resultados da Pesquisa
Item Factors affecting the specific heat of conventional and residue-based mortars.(2020) Mendes, Júlia Castro; Barreto, Rodrigo Rony; Castro, Arthur Silva Santana; Silva, Guilherme Jorge Brigolini; Peixoto, Ricardo André FiorottiThe present work investigates the specific heat of cement-based composites and the factors influencing it. To this purpose, coating mortars with Portland cement and hydrated lime were investigated, along with four types of aggregates: river sand, friable quartzite (QTZ), steelmaking slag (SLG), and iron ore tailings (IOT). Initially, the aggregates were characterised chemically and physically. Subsequently, the mortars were evaluated according to their physical and thermal properties. Adiabatic calorimetry was used to measure the specific heat of the samples in two conditions: oven-dried and saturated. The advantages and limitations of the method were discussed. Results showed that the microstructure of the mortars was more significant to the resulting specific heat than their chemical composition or density. Mortars with high specific heat and density, such as those with IOT and SLG, have great potential as sensible heat storage. Therefore, for application purposes, the specific heat should preferably be obtained through techniques that maintain the structure of the composite mostly intact, such as adiabatic calorimetry.Item Iron ore tailing-based geopolymer containing glass wool residue : a study of mechanical and microstructural properties.(2019) Silva, Keoma Defáveri do Carmo e; Santos, Letícia Figueiredo dos; Carvalho, José Maria Franco de; Peixoto, Ricardo André Fiorotti; Silva, Guilherme Jorge BrigoliniThis work presents an evaluation of the application of iron ore tailing as primary precursor material to geopolymer production. Glass wool residue from the iron ore industry was also included as a blend material. Four mixtures of geopolymers were produced: one mixture using only iron ore tailing; three mixtures where the iron ore tailing was replaced by the glass wool residue, with a substitution ratio of 10%, 20% and 30% (in mass). Furthermore, three different grinding times and three NaOH solution concentration were applied. Compressive strength and flexural strength tests were performed in prismatic specimens at 7-days, and the microstructural analysis of the fragments was obtained by SEM analysis. QXRD analysis based on the Rietveld’s refinement method and TG/DTA analysis was applied for all specimens. The results showed the synthesis of a zeolite phase in all specimens, and the SEM micrographs showed a transformation process of the glass wool residue. Finally, high mechanical performances were found to the iron ore tailing-based geopolymer, reaching values higher than 100 MPa for compressive strength and 20 MPa for flexural strength. The obtained values are related to the grain packing improvements, geopolymerization products, and the glass wool residue working as a supplementary precursor material to the geopolymerization reaction. The result points to the potential of iron ore tailing and glass wool residue to geopolymers studies and application.