Banca de QUALIFICAÇÃO: KÁSSIA LENE LIMA MARINHO
Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.DISCENTE : KÁSSIA LENE LIMA MARINHO
DATA : 29/11/2019
HORA: 09:00
LOCAL: UFOPA-Campus Amazon
TÍTULO:
Conversion of tailings from Kalunga dam (Pará) into nanomaterial with shigaita-type structure
PALAVRAS-CHAVES:
Tailings, Amazon, transformation, nanomaterial, clay
PÁGINAS: 65
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
RESUMO:
In this work, the transformation of Mn tailings from the Kalunga dam (Pará) into an anionic clay with layer structure was evaluated after chemical and mineral characterization of the tailings, as well as modification of the synthesis conditions (pH, cationic ratio, time and temperature). The characterization techniques were X-ray fluorescence, X-ray diffraction, Raman and infrared spectroscopy (FTIR), thermal analysis, scanning electron microscopy and transmission. The results showed that tailings composed of todorokite, lithiophorite, vernadite, cryptomelana, hollandite, birnessite, quartz, cristobalite, anatase, hematite and MnO content above 54% (weight) were successfully converted to anionic shigaite clay. Ideal conditions revealed that the material is formed at 75 ° C for 2 days, Mn2 +: Al3 + ratio of 4: 1, pH 11.2 with an average particle size of 25 nm. Typical FTIR bands of lamellar product of shigaite were observed in the range of 1100 to 400 cm -1. A typical plate morphology with average grain size of 5 m was observed. The thermal behavior of shigaita showed four main events related to water loss, dehydroxylation, structural destruction (~ 250 º) and oxide formation above 500 ºC. Thus, it was possible to propose the use of tailings from Amazon mining to produce a material of great technological relevance in adsorption processes, which may mean the reduction of waste disposal in the environment.
MEMBROS DA BANCA:
Presidente - 2142681 - BRUNO APOLO MIRANDA FIGUEIRA
Interno - 2143922 - ISRAEL NUNES HENRIQUE
Externo à Instituição - DORSAN DOS SANTOS MORAES - UFPA