Banca de DEFESA: Matheus Machado Lopes

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : Matheus Machado Lopes
DATE: 21/10/2022
TIME: 14:00
LOCAL: TEAMS
TITLE:

MECHANICAL AND MICROSTRUCTURAL ANALYSIS OF A ULTRAFINE IRON TAILING STABILIZED WITH POLYMERIC SOLUTION

KEY WORDS:

New Geotechnical Materials; Chemical Stabilization; Key Parameters; Tailing-Polymer Composite

PAGES: 110
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

Brazil was scene of major environmental disasters involving tailings dams in the last decade. Forty million cubic meters of tailings were released into the environment with the failure of the Mariana dam in 2015, affecting 663 kilometers of rivers and streams and 1,469 hectares of vegetation. In 2019, twelve million cubic meters were released with the rupture of the Brumadinho dam, losing more than 230 human lives. The demand for mineral materials grows more and more with the advancement of technology, which leads to the need to have a corresponding production. The greater the production, the greater the generation of tailings, which consequently leads to a need to think about the issues of disposal of this material, especially in the safety of dams. Another alternative is the reuse of tailings as material for engineering works, which is focus of this work, studying the chemical stabilization of an iron tailing with polymer. The studies were initiated with the view of the demand for pavements of enough quality so that trucks with ore or tailings can circulate freely during periods of rain. Considering that currently the mining complexes have difficulty moving their machinery in rainy periods, this becomes harmful to mineral production in a way that they make the extraction and processing processes unfeasible due to a logistical transport deficit within the mining complexes, leading to loss of productive capacity temporarily between these rainy periods. The physical characteristics of the iron ore tailings were then evaluated through the tests of specific gravity of the grains and granulometric analysis; chemical through x-ray fluorescence spectrometry (XRF/EDX) and energy dispersion x-ray spectroscopy (EDS) tests; hydraulic by permeability test; mineralogical by X-ray diffraction test (XRD); microstructural by scanning electron microscopy (SEM) and computed microtomography; and mechanics of the composite formed by the tailings and a styrene-acrylic copolymer, starting with the compaction test to determine the best moisture content to work the material; in sequence by uniaxial compression tests to determine the best polymer dosages, which were 40% and 30%; then examined these dosages at different densities (2.2 g/cm³, 2.3 g/cm³ and 2.4 g/cm³) in simple compression tests and direct shear tests at different confining stresses (50 kPa, 100 kPa, 150 kPa and 200 kPa) for an air cure time of 28 days. Finally, determining a mathematical correlation through the key parameters in an attempt to predict the behavior of the composite. The results corroborate that the use of polymers applied in tailings is a good alternative to improve this material so that it can be applied in engineering works. 

BANKING MEMBERS:
Externa à Instituição - GIOVANNA MONIQUE ALELVAN - UFMG
Interno - 404827 - ANDRE PACHECO DE ASSIS
Presidente - 1519113 - MICHELE DAL TOE CASAGRANDE
Interno - 3132829 - RAFAEL CERQUEIRA SILVA