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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Resultados da Pesquisa
Item Quartzite tailings in civil construction materials : a systematic review.(2023) Martins, Letícia Matias; Peixoto, Ricardo André Fiorotti; Mendes, Júlia CastroThe inadequate management of waste from the mining industry can lead to several environmental problems. For instance, the extraction of quartzite, an ornamental stone, generates quartzite waste (or residues or tailings) (QTZ), which is commonly deposited in the environment, causing landscape degradation, contamination by dust, and silting of rivers. To mitigate this scenario and stimulate the circular economy, this literature review focuses on the use of quartzite tailings in construction materials. A systematic search was carried out in the Scopus, Web of Science, and Google Scholar databases, including articles in English and Portuguese published between 2007 and 2022. The results showed that the use of QTZ as aggregate in cement-based composites is viable, as this waste has physical, chemical, mineralogical, and microstructural characteristics similar to conventional natural aggregate. Quartzite waste has been successfully adopted in precast concrete, cladding, and laying mortars, soil–cement bricks, and interlocking pavements. Many works brought the physical and mechanical characterization of the proposed construction materials, with gaps being observed mainly in terms of durability and performance. In conclusion, the use of QTZ in construction materials is a promising alternative, especially in cement-based composites. An important advantage is that this material requires little or no prior processing. However, the reuse of quartzite tailings is still limited, showing that more academic studies, private initiatives, and public policies are required.Item Incorporation of quartzite fines in the production of red ceramics.(2021) Silva, Mariana Caroline Andrade; Leão, Versiane Albis; Reis, Érica LinharesThe ornamental stone sector produces a substantial amount of solid waste and effluents that are discarded in a disorderly manner, a fact that has prompted the need for research aimed at reuse. Considering the concepts of sustainable development and conscious mining, this study proposed the incorporation of quartzite residues in the production of ceramics (using soil as raw material) and aimed to reduce production prices, minimize environmental impacts, and obtain a higher quality of ceramic products (with less water absorption and greater resistance). Ceramic bricks were made in accordance with the following variables: replacement percentage (10% and 15%), compaction pressure (28 and 35 MPa), drying temperature (65 C for 72 h and 110 C for 24 h), and firing temperature (950 and 1100 C). Technological tests evaluated the drying and firing linear shrinkage, firing specific weight, water absorption, and resistance to uniaxial compression. After determining the optimal conditions, a flexural tear test and microstructural characterization were also performed. The optimal conditions for making ceramic bricks were a replacement percentage of 15%, compaction pressure of 35 MPa, drying temperature of 65 C (72 h), and firing temperature of 1100 C. These results were favorable because of the partial thermal decomposition of the mineral phases with the recrystallization of mullite and cristobalite. The incorporation of the residue resulted in better quality ceramic products, placing them within the limits established for technological applications, whereas none of the compositions made entirely of clay met the technical specifications.Item Incorporation of waste from ferromanganese alloy manufacture and soapstone powder in red ceramic production.(2018) Cota, Tiany Guedes; Reis, E. L.; Lima, Rosa Malena Fernandes; Cipriano, Ricardo Augusto ScholzThe production of waste from the mining-metallurgical sector is one of the factors of environmental contamination and exploring ways to reuse this waste have attracted considerable research attention. This study proposes the use of residues generated from the manufacturing processes of ferromanganese alloy and soapstone powder for the production of red ceramic. Ceramic bricks were prepared with clay and sludge to investigate the effect of a number of variables, including the replacement of clay with sludge (5% and 10%), compaction pressure (14 and 28 MPa), and firing temperature (850 °C and 1000 °C) on the linear shrinkage, water absorption, firing specific weight, and compressive strength of the bricks. Also tests were carried out with replacement of part of the clay mass by sludge and steatite in the same brick. The best condition for ceramic production was found to be a firing temperature of 1000 °C and compaction pressure of 28 MPa with 5% of clay replaced by sludge. The best results were obtained for bricks with clay replaced by both sludge and steatite, which prompted the formation of the new crystalline phases, spinel and enstatite. After analysis, the brick residue was classified as Non Hazardous and Not Inert. The analyzed parameters were within the established limits for technological applications.Item Reuse of treated sewage effluent in airports : irrigation of ornamental plant nursery.(2013) Couto, Eduardo de Aguiar do; Assemany, Paula Peixoto; Calijuri, Maria Lúcia; Santiago, Aníbal da Fonseca; Alves, Luna Gripp SimõesAirports consume significant amounts of water which can be compared to the volume consumed by mid-size cities, thus practices aimed at reducing water consumption are important and necessary. The objective of this study was to assess the reuse potential of sewage effluent produced at a mid-size international airport for nursery irrigation. The sewage treatment system consisted of a facultative pond followed by a constructed wetland, which were monitored during one hydrological year and the parameters COD, pH, solids, nitrogen, phosphorus and Escherichia coli were analyzed. Removal efficiencies of 85% and 91% were achieved for COD and solids, respectively. Removal efficiencies for ammonia nitrogen and total phosphorus were 77% and 59%, respectively. In terms of E. coli concentration, the treated effluent met the recommendations by the World Health Organization for reuse in irrigation with the advantage of providing high levels of residual nutrient. The ornamental species Impatiens walleriana was irrigated with treated sewage effluent and plant growth characteristics were evaluated. The experiment showed that reuse can enhance plant growth without significantly affecting leaf tissue and soil characteristics. This study highlighted the importance of simple technologies for sewage treatment especially in countries which still do not present great investment in sanitation and proved that effluent reuse for landscape irrigation can provide great savings of water and financial resources for airport environments.Item Greywater production in airports : qualitative and quantitative assessment.(2013) Couto, Eduardo de Aguiar do; Calijuri, Maria Lúcia; Assemany, Paula Peixoto; Santiago, Aníbal da Fonseca; Carvalho, Isabella de CastroAirport complexes are great water consumers where the adoption of reuse practices adapted to their particular characteristics may represent significant savings of financial and environmental resources. Greywater reuse is an important alternative for reducing potable water consumption in airports. The objective of this study was to assess the quality of greywater produced in airport environments and the reuse potential of such effluent. This study was developed in a mid-size airport in Brazil, where a qualitative assessment of greywater produced by different activities was performed. The results were analyzed using descriptive and multivariate statistics. Greywater production in the administrative buildings was estimated by the application of questionnaires and interviewing employees, and compared to the nonpotable demand in these buildings. The results showed that the quality of the greywater produced in the airport is similar to that produced in residences and can be easily treated for reuse purposes. In quantitative terms, greywater reuse can meet the non-potable demand and provide great savings of water and financial resources, in addition to priceless environmental benefits.