Banca de DEFESA: LEONARDO LEANDRO DOS SANTOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : LEONARDO LEANDRO DOS SANTOS
DATA : 25/07/2018
HORA: 14:00
LOCAL: Auditório do NUPPRAR
TÍTULO:

Beta-spodumene lithium extraction through mechanisms with obtaining zeolites structures.

PALAVRAS-CHAVES:

beta-spodumene, lithium extraction, Li2CO3, high-throughput screening, molecuar sieves, zeolite cage structure, zeolite channel structures.

PÁGINAS: 100
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Cerâmicos
RESUMO:

The expected increase in the demand for lithium salts results in a growing concern about lithium scarcity and environmental problems in the national lithium extraction industry from renewable reserves whose extractive methodologies are associated with sulfates, organic solvents and the base of actinides, resulting in the formation of sulphated silicoaluminous byproducts and radioactive waste. Currently alternative sources of silicon and aluminum constitute new technologies in the synthesis of molecular sieves involving catalysis, separation, purification and gas storage as a great promise to scale-up applications. Therefore the objective of this study was to develop and design an environmentally efficient route for the extraction of lithium in salt form from beta-spodumene (β-LiAlSi2O6) and technologically viable to obtain by-product with zeolitic properties and properties. Literature studies describe methodologies for the extraction of lithium using sulphated additives, with post-synthesis by-product recovery, ie, this study is unprecedented in the development of zeolite crystalline microstructures en route from litiniferous extraction from beta-spodumene. Firstly in order to develop and design an efficient and economically feasible extraction route, it was important to understand the characteristics of molecular sieves, specifically zeolites. As a result the lithium extraction efficiency with Na2CO3, NaOH and NaCl additives was evaluated by means of atomic absorption measurements in the supernatant, resulting in up to 85% of lithium extracted, based on the chemoselective ion exchange between Li+ of β-LiAlSi2O6 and Na+ Na2CO3 and NaCl. The addition of NaOH promoted mineralizing action for the dissolution of β-LiAlSi2O6, facilitating Li recovery and Si and Al availability for nucleation and growth of zeolitic structures. Finally, two routes were developed, each operating in a closed and continuous circuit (HTS: high-throughput screening), comprising steps such as calcination, solubilization, hydrothermal treatment and bicarbonation, leading to lithium extraction and by-product with zeolite-cage (LTA and FAU) or zeolite-channel topology (LTT, MOR and MFI). The materials were characterized by several techniques such as XRD, TGA/DTA, ICP, adsorption isotherms of N2, SEM, TEM and FTIR with adsorbed pyridine to validate the strategies used.

MEMBROS DA BANCA:
Interno - 1300987 - CARLOS ALBERTO PASKOCIMAS
Externo à Instituição - LINDIANE BIESEKI - UFRN
Externo à Instituição - MANUEL KARIM SAPAG - UNSL
Interno - 1350249 - RUBENS MARIBONDO DO NASCIMENTO
Presidente - 1308577 - SIBELE BERENICE CASTELLA PERGHER
Externo ao Programa - 2087667 - TIAGO PINHEIRO BRAGA