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Publicações Científicas e Culturais 22760
Recursos Educacionais 447
Trabalhos Acadêmicos 52847

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Adsorção de ouro com carvão ativado: avaliação da regeneração e seus efeitos no processo
(Universidade Federal de Minas Gerais, 2025-06-28) Marcelo Jordão Nascimento Pereira
This study aimed to evaluate the efficiency of thermal regeneration applied to activated carbon used in the CIL circuit of a gold processing plant. Two experimental campaigns were conducted using real operational samples, submitted to different acid washing and thermal treatment conditions. Adsorptive activity was determined through bench-scale kinetic tests. Results showed that thermal regeneration significantly restored performance, with activity levels above 80%. Washing with higher HCl concentration outperformed HNO₃ (41% vs. 22% activity, respectively), and the removal of fine particles proved to be an important practice to preserve process efficiency. The findings reinforce the technical feasibility of thermal regeneration as a strategy to maintain adsorptive performance.
MannaWUIG: um gateway de canal duplo com tecnologia LoRa para redes de pequeno e médio porte
(Universidade Federal de Minas Gerais, 2025-10-09) Wuigor Ivens Siqueira Bine
The use of the Internet of Things (IoT) with low-power wide area network technologies (LPWANs) is providing significant advances for different sectors, such as smart cities, smart metering, precision agriculture, industry 4.0, among other scenarios, helping decision mak- ing for more efficient solutions/applications. LoRa is a promising technology for LPWAN networks and has been the focus of studies and applications used in simultaneousness with the LoRaWAN communication protocol. Networks that choose to use LoRaWAN have the characteristics of random access upstream, which in networks with many devices promote packet collisions, congestion, latency, and higher battery consumption by the devices. A solution to this problem is the use of gateways capable of receiving simultaneous data on different channels. However, they have a high acquisition cost, consuming a good part of the budget for small and medium-sized private networks. This work proposes an intelligent gateway design and development for IoT applications in small and medium-sized networks, aiming for a national technology creation in this area.
Estratégia de controle do fluxo de potência de um cluster avançado de média tensão com estações de recarga rápida de veículos elétricos e microrredes avançadas
(Universidade Federal de Minas Gerais, 2025-11-07) Dener Augusto de Lisboa Brandão
In this doctoral thesis, control strategies are presented for grid clusters composed of advanced microgrids and fast-charging stations (FCSs). The proposed approach offers more degrees of freedom in energy management, contributing to the mitigation of abrupt power variations in the grid, with a focus on medium-voltage operation and on ensuring power supply within the electrical system. The challenges addressed include the control of power flow in the presence of high penetration of distributed generation and the impact of FCSs on power quality. The work proposes adaptations of the power-based control (PBC) algorithm to deal with such conditions, enabling both local power balancing and the provision of ancillary services to the grid, such as peak shaving, valley filling, and voltage support. The proposed system was evaluated in two distinct modes of operation: grid-connected and islanded. In both modes, centralized and coordinated power control solutions were developed and tested. The simulation results showed that the proposed algorithm is capable of maintaining the voltage at the point of common coupling (PCC) of the grid cluster within the limits considered adequate, as established by the PRODIST standards of ANEEL. Moreover, the methodology proved robust against load and generation variations within the grid cluster in islanded mode, considering simulations with phasor-based solvers. The proposal was also experimentally validated in a small-scale laboratory environment, confirming its practical feasibility. It was possible, for instance, to achieve zero power flow at the PCC, demonstrating internal power balancing, an essential condition for islanded operation.
Efeito da distribuição granulométrica e da umidade na performance das prensas de rolos da Ferro+ Mineração
(Universidade Federal de Minas Gerais, 2024-08-28) Mauro Lucio Teixeira Junior
The optimization of comminution through High Pressure Grinding Rolls (HPGR) is essential for operational efficiency in the particle size adjustment of itabirite ores. The use of HPGR has proven to be a promising alternative for particle size reduction; however, challenges such as material moisture and the presence of fines affect equipment performance. In this context, the evaluation and improvement of the comminution circuit are fundamental to ensuring operational continuity and maximizing the efficiency of both the presses and the processing plant. The objective of this study was to evaluate the performance of HPGR units in the industrial circuit and propose improvements in the processing of current and future ores, identifying factors that affect the efficiency of the presses and proposing operational adjustments that increase the generation of fine fractions (<1.00 mm), thereby optimizing the performance of the subsequent concentration circuit. The methodology involved detailed mapping of the industrial process, identification of critical stages, sampling and particle size analyses, as well as characterization of the processed material. The effects of moisture were also evaluated through photographic records and visual documentation. Industrial tests, blend formation, and in situ experiments made it possible to propose changes in the beneficiation route aimed at improving the efficiency of the presses. The results showed that the presence of fines (<2.00 mm) in the feed and high moisture content reduce comminution efficiency. In collaboration with the R&D team, a brainstorming session identified operational bottlenecks and optimization strategies. It was found that the screening stage preceding the presses (PNs-08) requires improvement, as the recirculation of fines as circulating load compromises the circuit’s performance. Moreover, the expected increase in ROM particle size from 2027 onwards will require additional improvements to prevent circuit overload. Excessive moisture was confirmed as a critical factor, reducing material adhesion to the rolls and the grinding efficiency. In summary, the study broadens the understanding of HPGR application on an industrial scale and provides technical support for operational and strategic decision-making, reinforcing the importance of integrating applied research and industrial practice as a key factor for the sustainability and competitiveness of the mining sector.
Reservatórios metálicos para armazenamento de água potável
(Universidade Federal de Minas Gerais, 2025-09-26) Giulliano Digiorgio Andriola Damasceno
This study addresses the analysis of pathological manifestations in cylindrical steel tanks designed for potable water storage. The research aims to identify and examine the main structural pathologies affecting these tanks, considering design, fabrication, and maintenance aspects. To achieve this, inspections were carried out on several tanks installed in different regions of Brazil, using visual methods and non-destructive testing techniques. The results indicated corrosion as the primary cause of structural degradation, particularly in coastal areas. Furthermore, the study emphasizes the importance of rigorous inspection and monitoring during the manufacturing process of steel tanks to prevent deformations, welding defects, and other pathologies that compromise structural safety and durability. The research concludes that the absence of specific standards for this type of structure in Brazil, combined with inadequate maintenance practices, significantly contributes to the reduction of the tanks’ service life. Preventive strategies are recommended, such as the use of appropriate coatings, regular inspections, and strict quality control during fabrication, to ensure the integrity and longevity of these structures.

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