Recuperação de metais de catalisadores mássicos e monometálicos

Afonso, Júlio Carlos; Lima, Tatiana Siqueira de; Campos, Paula Constante; Pinheiro, Ana Acácia de Sá

doi:10.1590/s0100-40422003000600024

Cited by 3 publications

(3 citation statements)

References 6 publications

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“…The idea is to highlight the specific knowledge of the interviewee in the art of Engineering linked to offshore activities. Therefore, the literature consulted offers partial support to the analysis of the discourses of the research participants [14][15][16]. Table 3 presents the questions applied to the selected respondents.…”

Section: Semi-structured Interviewsmentioning

confidence: 99%

A 2022 vision of offshore engineering professionals on the application of agile methodologies

Andrade¹,

Mainier²,

Monteiro³

2023

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It has been observed the recognized effectiveness of the use of Agile Methodologies in Information Technology (IT) projects and the discreet application of these methodologies in Engineering projects. The present work aims to carry out a study of the use of Agile Methodologies in the design and manufacturing phases of offshore equipment, allowing the profile of the population most familiar with these methodologies to be drawn, as well as to seek information regarding their implementation. For the development of this study, a questionnaire elaborated with nineteen questions was sent to one hundred and seventy respondents, in addition to conducting interviews with seven of these respondents, which allowed, thus, to gather information about the area of activity, the level of education, the age, years of experience of the respondents, among other information, characteristics, and aspects. In conclusion, this study manages to draw a parallel between the use of Traditional and Agile Methodologies, indicating which are the most used and informing the perception of professionals regarding the use of these methodologies.

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Section: Semi-structured Interviewsmentioning

confidence: 99%

A 2022 vision of offshore engineering professionals on the application of agile methodologies

Andrade¹,

Mainier²,

Monteiro³

2023

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“…A dissolução em meio contendo HF + H 2 O 2 de catalisadores zeolíticos desativados pode ocorrer em tempo curto, permitindo o isolamento direto de aditivos de alto valor agregado, como os lantanídeos. O sucesso deste procedimento mostra a aplicabilidade do processo de dissolução em meio contendo fluoreto, inicialmente aplicado a catalisadores à base de alumina (NiMo, CoMo/Al 2 O 3 , Pt/ Al 2 O 3 , etc) 17 , para amostras contendo simultaneamente silício e alumínio, contanto que a amostra não contenha metais alcalinos ou alcalino-terrosos, pois neste caso, ocorreu abundante precipitação do Al como criolita (Na 3 AlF 6 ) e do Ca (CaF 2 + Ca 3 (AlF 6 ) 2 ), comprometendo a recuperação dos referidos elementos em formas reutilizáveis industrialmente com rendimento satisfatório. A obtenção de fluoretos de valor comercial (criolita e NaF + Na 2 SiF 6 ) reduziu grandemente o volume de resíduo gerado no processo.…”

Section: Conclusõesunclassified

“…Foram empregados métodos convencionais de tratamento por fusão. Em outra série de experimentos, tentou-se recuperar componentes dessas zeólitas empregando soluções contendo o íon fluoreto, aproveitando suas propriedades complexantes, o que permite utilizar condições experimentais brandas (tempo e temperatura) como aplicadas em nosso laboratório a outros tipos de catalisadores 17 .…”

Section: Introductionunclassified

Reciclagem química de zeólitas comerciais desativadas

et al. 2004

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Recebido em 24/3/03; aceito em 21/7/03 CHEMICAL RECYCLING OF SPENT COMMERCIAL ZEOLITES. Pyro and hydrometallurgical processes were applied to the treatment of spent commercial zeolites (a molecular sieve and a ZSM-5 sample). Both catalysts were employed in pilot plant units. They were kept in their original shape, they were not regenerated and were not subjected neither to mechanical stress nor to overheating zones during their time on-stream. Two recycling processes were tested: (i) direct solubilization of samples in mixtures of HF + H 2 O 2 (60 o C, 1 h). Although silicon was solubilized, insoluble matter was found in both samples, particularly in the molecular sieve, due to its high amounts of alkaline and alkaline-earth metals; (ii) fusion with KHSO 4 (5 h, 600 ºC) with KHSO 4 /zeolite mass ratio 6:1. After fusion the solid was solubilized in water (100 ºC), leaving silicon as SiO 2 residue. In both processes, solubilized metals were isolated by conventional selective precipitation techniques. Analysis of final products by common analytical methods shows that metals present in the original catalysts were recovered with very high yields except when the molecular sieve was treated with HF + H 2 O 2. This reactant mixture proved to be suitable for processing zeolites with a low alkaline and alkaline-earth metal content whereas fusion with KHSO 4 appeared to be adequate for all types of zeolites.

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