Eletroflotação De Finos E Ultrafinos De Minério De Ferro Com O Uso De Um Biossurfactante Extraído Da Bactéria Rhodococcus Opacus

Abstract

Primeiro agradeço a Deus, pelo dom da vida, por me ajudar nos dias difíceis, sem ele nada disso seria possível. Agradeço ao meu orientador, o Professor Dr. Maurício Leonardo Torem, pela confiança, paciência e ensinamentos. Ao meu coorientador, Dr. Ronald Rojas Hacha, pela ajuda no laboratório, pela paciência, compreensão e ensinamentos científicos e de vida. Ao Departamento de Engenharia Química e Materiais (DEQM) da PUC -Rio, seus professores, pesquisadores e funcionários, pela oportunidade de realização do curso, experiências trocadas, conhecimento transmitido, colaboração e incentivo. A minha família, principalmente meus pais, Mônica e Cesar e a minha irmã Cláudia por todo amor, carinho, compreensão e auxílio, sem eles também nada disso teria acontecido. Agradeço aos meus colegas de curso e laboratório, em especial Luana Nascimento, Carlos Moura, Jesana Moura, Marcelo Camarate, Elivone Lopes e Antonio Gutiérrez Merma que foram meus companheiros do dia-a-dia e que muito me ajudaram. Ao CNPq, à FAPERJ e à PUC-Rio, pela concessão dos auxílios financeiros. O presente trabalho foi realizado com o apoio da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior -Brasil (CAPES) -Código de financiamento 001. PUC-Rio -Certificação Digital Nº 1821076/CA Palavras-chaveEletroflotação; biossurfactante; minério de ferro; hematita; quartzo.

Hematite Flotation Using Mixed Bioreagent Systems Extracted From Rhodococcus Opacus and Rhocococcus Erythropolis

“…It is known that when the hematite is pure, the IEP occurs in acid to neutral pH region (Carlson & Kawatra, 2013;Quast, 2015). Moreover, the hematite IEP could appears in the region of pH close to 2.2 -6.9, wich are in a good agreement with reported values of hematite IEP using sodium chloride as indifferent electrolyte (Parks, 1965;Lopez, 2015;Olivera 2014;Camarate 2019;Simoes 2020). Furthermore, there are diffferent factors that could affect the zeta potential of iron oxides like mineral heterogenity, impurities sealed in the particles and also the ageing of the particle surface (Quast, 2015).…”

“…Some literatures explain that biosurfactants extracted from the genus Rhodococcus presents a complex structure that make these biosurfactants as substances with anionic characteristics, and for this reason quartz particles do not acquire positive charge at low pH (Simoes, 2020). Kelly & Spottiswood (1982) reports the quartz IEP value between 2-3.7 and other researches as Natarajan & Deo (2001); Mesquita et al (2003) observed similar behaviour in the zeta potential profile for quartz after interaction with biosurfactants from genus Bacillus and Rhodococcus respectively.…”

“…Different nonpathological microorganisms have been widely used in bioflotation processes. Bacterium from genus Rhodococcus as Rhodococcus erythropolis and Rhodococcus opacus, have proven their behaviour as a biocollectors for hematite flotation besides other mineral ores (Mesquita et al, 2003;Yang et al, 2013;Hacha et al, 2018;Simoes 2020). Other microorganisms used as bioreagents to sepate specific minerals of interest are shown in Table 2.…”

“…(Figure 34) The stretching vibration of OH that could correspond to the presence of polysaccharides and proteins (Simoes et al, 2020) has been transferred to peak at 3428.13 cm -1 . The peak at 1628.14 cm -1 may be attributed to the bending vibration of the interaction between the C=O group and the hematite hydroxyl metal group (Tohry et al, 2021).…”

“…In all cases the value of contact angle angle values of hematite in a huge range where 36° could be considerated as hydrophilic mineral or slightly hydrophobic raising contact angle of about 50° in neutral pH (Yin et al, 2017;Shrimali t al., 2016). According to Simoes (2020), in acidic pH the contact angle is smaller because the surface charge with the same value probably are repulsed. Furthermore, each curve shows a little slop through the pH range increases, at that point we can affirm the hematite becomes more hydrophobic.…”