Banca de QUALIFICAÇÃO: THIAGO MOURA DE QUEIROZ E OLIVEIRA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : THIAGO MOURA DE QUEIROZ E OLIVEIRA
DATE: 05/07/2023
TIME: 18:00
LOCAL: Araxá - MG
TITLE:

STACKING A DEWATERED PHOSPHATE SLUDGE: CHARACTERIZATION, NUMERICAL MODELING AND DESIGN CRITERIA

KEY WORDS:

Mining; Piles; Filtration; Tailings; Slimes. 

PAGES: 55
BIG AREA: Engenharias
AREA: Engenharia de Minas
SUBÁREA: Pesquisa Mineral
SPECIALTY: Caracterização do Minério
SUMMARY:

In terms of a scenario where mining operations are being increasingly demanded to be aligned with the principles of sustainability, transparency and safety operations for the communities, tailings production, whether in disposal or reuse, have become one of the main actors for the implementation and achievement of goals of these practices, of which we can highlight the ESG (environmental, social and governance) and the SDG’s (sustainable development goals) of the UN (United Nations), where, in terms of tailings, studies and implementation of new technologies for disposal or reuse are in evidence. Linked to this framework, mineral deposits tend to be mined with lower grades, which, added to the growing world demand for mining products, will tend to generate more and more tailings. In addition, due to the latest tailings dams failures (Mont Polley – 2014, Fundão – 2015 and Brumadinho – 2019) we had the worldwide rise of guides with the aim of standardizing the management of tailings disposal structures of which we can mention the GISTM (Global International Standard of Tailings Management) with the mission of zero fatalities to the population with tailings disposal structures and to provide guidelines and criterias to better understand the behaviour of the tailings storage facilities during all phases of its life-cycle. Futhermore, there were also several changes in Brazilian legislation, which made the requirements for obtaining licenses to operate new tailings dams more stringent, in addition to the public outcry against this type of structure. In this way, one of the most promising alternatives to replace the common operation with tailings dams are the Tailings Piles. This type of structure is only achievable due to technological advances in filtration with the removal of water to allow the material to be stacked. However, dewatering 100% of the production of tailings and stack it often still requires studies and challenges, because you must consider the fine part of tailings, called sludge or slurry, presents greater difficulty in filtration. Also, depending on the partition and mass balance of the types and volumes of tailings generation, it may be necessary to mix the coarser fraction of tailings with the sludge to improve filtration rates and to reduce the moisture content of the cake bringing closer to the optimum moisture content that are one of the parameters that must be in the quality control during the construction of this type of structure. Therefore, because they are new structures and generally never operated before, there are no specific legislations and no historical operations for decades as we have for tailings dams. Thus, establishing satisfactory design criterias, characterization tests and semi-industrial tests, such as experimental fills, become essential steps to guarantee the safety, constructability, operation and closure of the tailings piles. So this work aims to study and discuss design criterias regarding implementation of tailings piles in the literature, discussing also legal obligations or current technical standards and carry out a numerical modeling with stability evaluation using equilibrium-limit methods from laboratory tests and bench tests, carried out by a phosphate mining company that wants to evaluate the implementation of the dewatering and stacking 100% of its tailings production including the sludge fraction.

COMMITTEE MEMBERS:
Presidente - THIAGO BOMJARDIM PORTO
Interna - MICHELLY DOS SANTOS OLIVEIRA
Externo à Instituição - SAULO GUTEMBERG SILVA RIBEIRO - PUCMinas