Navegando por Assunto "Residues"

Agora exibindo 1 - 5 de 5

Acesso aberto (Open Access)
Contribuição para o desenvolvimento de compósito cimento-madeira com materiais da região amazônica
(Universidade Federal do Pará, 2005-06) FONSECA, Fábio de Oliveira; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
This work intends to propose an application for tropical wood waste from wood industry as saw dust; from the region of Belem, in the fabrication of wood-cement composite. Due to the natural chemical incompatibility between wood and cement, this procedure results in a set retarding effect, with wood specie depending intensity. This by-effect can be beaten by using a procedure like additives, wood mineralization, accelerated carbonation and others. Analysis were made with axial compression strength at 28 days age data, for mortars made with 2, 3.5 and 5% wood content in mass; using cements type CP I and CP II; with and without Calcium Clorets-based set accelerator additive. Then, obtained data were statistically analyzed for evaluation on wood content and additive use over mechanical resistance. Most of existing researches uses reforesting species, being the tropical ones almost never studied. So, this work represents a pioneer effort in developing a cement-bonded wood composite with our regionally available materials and residues.
Acesso aberto (Open Access)
Estudo cinético do processo fermentativo da seiva do tronco do óleo de palma (elaeis guineensis jacq.) para fins alimentícios
(Universidade Federal do Pará, 2018-04-09) VEIGA, Juliane Almeida; CORRÊA, Nádia Cristina Fernandes; http://lattes.cnpq.br/5763999772352165
The palm oil agro-industry generates millions of tons of solid biomass, among which trunks stand out. The sap contained in the central region has the highest concentration of fermentable sugars, making it an alternative raw material for the production of co products such as syrup, bioethanol and fermented alcoholic beverages. Therefore, the objective of the research was the kinetic study of the palm oil trunk sap for possible elaboration of a fermented beverage within the alcoholic standards required by Brazilian legislation. Introducing the raw sap: moisture content of 96.07%, ash content of 0.78%, pH 5.65, titratable acidity of 2.64%, specific mass of 1.02 g/cm3,°Brix of 8,03, concentration of total and reducing sugars of 55.89 g/L and 32.71g/L, respectively. To carry out the kinetics, the conditions of the crude sap were adjusted, through the process of evaporation by concentration, after treatment: 14 °Brix, pH 4.0, total and reducing sugars of 72.51 g/L and 55.89 g/L, varying only the concentration of initial cells (2.0, 3.5 and 5.0 g/L). A statistical analysis that there was no explained difference between the alcohol levels obtained. Presenting the inoculum with 5.0 g/L the best kinetic parameters for conversion of substrate into cells (YX/S 0.10), substrate into product (YP/S 0.41), efficiency (77.87%), productivity (1.72 g.L-1/h-1), μmax (0.07 h-1) and percentage of EtOH (3.50 °GL (% v/v))
Acesso aberto (Open Access)
Estudo da influência da incorporação dos resíduos de caulim nas propriedades tecnológicas de cerâmica marajoara para obtenção de tijolo ecológico
(Universidade Federal do Pará, 2025-07-30) BRITO, Fabio Moreira; CÂNDIDO, Verônica Scarpini; http://lattes.cnpq.br/8274665115727809; https://orcid.org/0000-0002-3926-0403; MONTEIRO, Sérgio Neves; http://lattes.cnpq.br/2962183322412029; https://orcid.org/0000-0003-1208-1234
The effects of global climate change are occurring at an unprecedented pace. For this reason, human activities urgently require a paradigm shift to halt this entropic process before the consequences become irreversible. In this context, the use of highly eco-efficient materials aims to conveniently neutralize CO₂. This study aims to incorporate Kaolin waste—KDI (clayey) and KAI (sandy)—into the properties and microstructures of clay mass, assessing its mechanical strength after firing at temperatures of 750 and 950 °C. Within this framework, six formulations were tested, varying from 0% to 50% kaolin waste. The specimens were uniaxially pressed into cylindrical shapes and then subjected to firing at 750 °C and 950 °C for 2 hours at peak temperature. The raw materials underwent tests that provided a comprehensive characterization of their properties, such as X-ray diffraction (XRD), X-ray fluorescence (XRF), optical microscopy (OM), scanning electron microscopy (SEM), and laser diffraction techniques (LD). After mixing and forming the materials into test specimens with different compositions, they were uniaxially pressed in cylindrical molds and subjected to compression testing. The results demonstrated the feasibility of using these wastes, showing favorable outcomes for their incorporation into red ceramics for the production of ceramic products in compliance with current standards.
Acesso aberto (Open Access)
Estudo da influencia do residuo de beneficiamento de cobre sulfetado nas propriedades do concreto asfaltico
(Universidade Federal do Pará, 2016-11-25) KATO, Ricardo Bentes; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968
With the development of industrial society, the demand for raw material has been increasing steadily over the last decades. Linked to this development occurs the generation of residues, which in the case of copper approximately 1% of the soil is exploited and transformed into commercial copper, the other 99% become waste of the process, being deposited in containment basins, where it is estimated 90 million tons the quantity contained in the Canaa dos Carajas plant, from where the residue of this work was obtained. This leads to high construction and maintenance costs, as well as generating a hazardous environmental liability. The objective of this work was to evaluate the addition of copper mining residue in replacement of the small aggregate in CA. In the dosage design it was verified that the content of 10% of residue in substitution to the small aggregate, more precisely 7.73% (obtained by regression), as the proportion that best suited the Marshall properties, even with lower CAP content In relation to the others, fact this provided by the type of fines of the residue. In general, the measured mechanical properties were not altered by the presence of the residue, except for the fatigue data, where the 20% and 25% mixtures showed superior performance, mainly because the resilience modulus values were statistically the same. The rheological data, compared to Superpav classification, were also unchanged, as well as the coating thickness given in the simulation in the SisPav, being in the order of 5 cm. In analyzing the potential for the use of waste, a positive conclusion was reached regarding the technological, environmental and economic aspects, with the possibility of consumption of more than 1.500.000 tons in roads close to the project, besides the economy with CAP consumption and Portland cement for trace correction.
Acesso aberto (Open Access)
Utilização de resíduos da indústria madeireira para fabricação de chapas cimento-madeira
(Universidade Federal do Pará, 2005-11-11) SOUZA, Alberto Alexandre Costa e; POMPEU NETO, Bernardo Borges; http://lattes.cnpq.br/6564259204591721; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
The wood industrialization generates residues big quantity, that are thrown in the environment, and they aren't profited in your totality, or when at most are used to energy generation causing also environmental pollution. This research had as objective to evaluate by means of physical, interface fiber-head office mechanical rehearsals and analysis, for sweeping electronic microscopy, the lumber industry residues utilization for cement-wood particleboard molding. They were going evaluated the compatibility of six dicotyledonous species native of Amazonian, and their mixture in equal parts, with compression axial rehearsals in cylindrical bodies-of-proof, for choice of that better performance for application in cement-wood particleboard. The residues were going used to the natural and submitted to the treatment wash in hot water for two hours, for influence verification of this treatment. The used cement was CP V ARI, with the relation cement/wood 3: 1 on mass, together with the additive accelerators of catches aluminum sulfate to 3% and calcium chloride to 3% and 5%. The results of compression axial rehearsal indicated three species with potential for use in plates, with the treatment wash agreement with the accelerator of catches calcium chloride to 5%. The species Cedrela odorata L. (Cedar), exhibited the best performance in the physical and mechanical rehearsals, overcoming plates manufacturers specifications, being, potentially the residue more indicated for utilization in cement-wood particleboard.