Efeito da adição de resíduos sólidos nas propriedades químicas e mineralógicas de geopolímeros
Data
2021-07-07
Autores
Umeda, Thaisa Natiele [UNIFESP]
Orientadores
Shinzato, Mirian Chieko [UNIFESP]
Tipo
Trabalho de conclusão de curso de graduação
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Geopolímeros são materiais formados por aluminossilicatos e soluções alcalinas altamente concentradas, sintetizados à temperatura ambiente. Aluminossilicatos estão presentes em de diversos resíduos sólidos da indústria do alumínio e demais atividades mineradoras que podem ser reaproveitados como matéria-prima de geopolímeros. O presente projeto teve por objetivo analisar o efeito da adição de resíduos da indústria do alumínio, lama vermelha (LV) e resíduo de reciclagem de alumínio (R2) na confecção de geopolímeros com metacaulinita. Esses materiais foram aquecidos a 600 °C para promover a formação de compostos mais reativos (produtos de baixa cristalinidade) com o hidróxido de alumínio e produzir geopolímeros. Foram então caracterizados química e mineralogicamente. No geral, os espectros de FTIR indicaram grupos funcionais típicos de zeólitas, composição que caracteriza os geopolímeros como as bandas relacionadas às vibrações de estiramento das hidroxilas e bandas que indicam as ligações Si-O e Al-O. A análise mineralógica indicou presença de fase com menor cristalinidade, além dos minerais mais resistentes ao aquecimento e à solução alcalina utilizada no processo de geopolimerização. Compararam-se duas metodologias, uma tradicional e outra de fusão alcalina, onde se verificou nenhuma mudança quanto à formação de grupos funcionais. Novas análises mineralógicas em geopolímeros confeccionados pelo método 2 poderão revelar se houve formação de novas fases, como de zeólitas.
Geopolymers are materials formed by aluminosilicates and highly concentrated alkaline solutions, synthesized at room temperature. Aluminosilicates are present in several solid residues from the aluminum industry and other mining activities that can be reused as raw material for geopolymers. This project aimed to analyze the effect of adding waste from the aluminum industry, red mud (LV) and aluminum recycling waste (R2) in the manufacture of geopolymers with metakaolinite. These materials were heated to 600 °C to promote the formation of more reactive compounds (low crystallinity products) with aluminum hydroxide and produce geopolymers. They were then characterized chemically and mineralogically. In general, the FTIR spectra indicated functional groups typical of zeolites, a composition that characterizes geopolymers as bands related to hydroxyl stretch vibrations and bands that indicate Si-O and Al-O bonds. The mineralogical analysis indicated the presence of a phase with lower crystallinity, in addition to minerals more resistant to heating and to the alkaline solution used in the geopolymerization process. Two methodologies were compared, one traditional and the other alkaline fusion, where no changes were found regarding the formation of functional groups. New mineralogical analyzes in geopolymers made by method 2 may reveal whether new phases, such as zeolites, were formed.
Geopolymers are materials formed by aluminosilicates and highly concentrated alkaline solutions, synthesized at room temperature. Aluminosilicates are present in several solid residues from the aluminum industry and other mining activities that can be reused as raw material for geopolymers. This project aimed to analyze the effect of adding waste from the aluminum industry, red mud (LV) and aluminum recycling waste (R2) in the manufacture of geopolymers with metakaolinite. These materials were heated to 600 °C to promote the formation of more reactive compounds (low crystallinity products) with aluminum hydroxide and produce geopolymers. They were then characterized chemically and mineralogically. In general, the FTIR spectra indicated functional groups typical of zeolites, a composition that characterizes geopolymers as bands related to hydroxyl stretch vibrations and bands that indicate Si-O and Al-O bonds. The mineralogical analysis indicated the presence of a phase with lower crystallinity, in addition to minerals more resistant to heating and to the alkaline solution used in the geopolymerization process. Two methodologies were compared, one traditional and the other alkaline fusion, where no changes were found regarding the formation of functional groups. New mineralogical analyzes in geopolymers made by method 2 may reveal whether new phases, such as zeolites, were formed.