Recovery of platinum from spent catalysts in a fluoride-containing medium

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

doi:10.1016/j.hydromet.2004.01.001

Cited by 47 publications

(23 citation statements)

References 8 publications

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“…They were fed into a milling machine for size reduction (100% < 1 mm, 30 min). This mass was dried at 40 All calculated values of ΔG 0 are negative. It follows that the reactions occur with high probability in the direction of product formation under the temperature range used, as described earlier.…”

Section: Methodsmentioning

confidence: 99%

“…17,38 This acid has already been investigated as a leachant for spent catalysts. 39,40 Different from many carboxylic acids (citric, malic, succinic, oxalic, iminodiacetic, tartaric), 5,21 formic acid has apparently not been tested yet. Like oxalic acid, the simplest aliphatic monocarboxylic acid is a strong reductant, but does not precipitate metal ions as does oxalate.…”

Section: Introductionmentioning

confidence: 99%

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PROCESSING OF SPENT ZINC-MnO2 DRY CELLS IN VARIOUS ACIDIC MEDIA

et al. 2017

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publicado na web em 04/12/2017 This paper describes a route for recovering manganese and zinc from spent zinc-MnO 2 dry cells via acid leaching. Sulfuric, hydrofluoric and formic acids were used as leachants. Hydrogen peroxide was added as reductant, except for formic acid since it is itself a reductant. Experiments were run at 25-40 o C for 1-3 h. Under the best optimal conditions, over 95 wt.% of zinc and manganese were leached irrespective of the leachant. Leaching of contaminants was strongly dependent on the leachant due to the insolubility of salts or complexing reactions. Zn(II) was best extracted with D2EHPA diluted in n-heptane at pH > 1, particularly from the leachates of weak acids. Mn(II) was much more co-extracted from sulfuric leachates, but was easily scrubbed with dilute leachant (~2 mol L -1 ). Zn(II) striping was possible using 5 mol L -1 H 2 SO 4 . Manganese was isolated as MnO 2 carrying the leached contaminants. High-purity sodium salts of the anions of the leachants were recovered after slow evaporation of the final solution.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

PROCESSING OF SPENT ZINC-MnO2 DRY CELLS IN VARIOUS ACIDIC MEDIA

et al. 2017

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“…This phenomenon is called the spillover effect [20]. After removing the Al 2 O 3 and the SBA-15 supports, the liberated coke consisted of coke and Pt metal because Pt metal does not dissolve in the HF solution [21]. The oxidation temperatures of both liberated cokes were lower than that of the coke on each catalyst prior to removing the support.…”

Section: Catalyst Performancementioning

confidence: 99%

Oxidation of Coke Formed Over Pt-Al2O3 and Pt-SBA-15 in Propane Dehydrogenation

Bok

Ahn

et al. 2009

Catal Lett

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In this study, different oxidation patterns of coke over 3% Pt-Al 2 O 3 and 3% Pt-SBA-15 catalysts were observed but the same catalytic performance was obtained in the dehydrogenation of propane. The oxidation peaks of coke on 3% Pt-Al 2 O 3 appeared at 416 and 513°C, while only one sharp peak was present at 556°C in the coke oxidation pattern of 3% Pt-SBA-15. Using the XRD patterns, it was confirmed that the structure of the coke formed over the catalysts was the same. The TPO profiles indicated that the relative distance of coke from the metallic phase (coke location) and the oxygen mobility on each support played important roles in the oxidation of coke.

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“…7,16 Aparentemente não há menção ao uso de ácido fluorídrico. O íon fluoreto é uma base muito forte e forma complexos muito estáveis com cátions contendo configurações de gás nobre (os ácidos duros) [21][22][23] Ao contrário de diversos ácidos carboxílicos usados como complexantes (cítrico, málico, succínico, tartárico, oxálico), 2,16 o ácido fórmico parece não ter sido testado. Tal como o ácido oxálico, o mais simples dos ácidos monocarboxílicos alifáticos é um poderoso agente redutor, mas não precipita íons metálicos como no caso do oxalato.…”

Section: Introductionunclassified

Lixiviação Ácida De Baterias Íon-Lítio

Silva¹,

Afonso²,

Mahler³

2018

Quim. Nova

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publicado na web em 22/02/2018 ACIDIC LEACHING OF Li-ION BATTERIES. This paper describes a route for recovering cobalt and lithium from spent Li-ion batteries via acidic leaching. Sulfuric, hydrochloric, hydrofluoric and formic acids were used as leachants. Hydrogen peroxide was added as reductant, except for formic acid since it is itself a reductant. Experiments were run at [25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] o C for 1-3 h. Under the best optimal conditions, the leaching efficiency order was HCl ≈ HF > H 2 SO 4 > HCOOH. Over 90 wt.% of cobalt and lithium were leached by the inorganic acids. The insoluble matter corresponds mainly to the carbon from the cathode. Co(II) was extracted with D2EHPA 16 vol.% diluted in n-hexane at pH ~5 (A/O ratio 1/1 vol/vol, one stage, 25 °C). Co(II) striping was possible using a dilute leachant (1-2 mol L -1 HCl or H 2 SO 4 , 4-5 mol L -1 HF or HCOOH). Lithium was isolated from the raffinate by precipitation as carbonate or phosphate.Keywords: lithium-ion battery; metals recovery; solvent extraction; cobalt; lithium. INTRODUÇÃOAs baterias de íon-lítio por apresentarem uma elevada densidade de energia, vida útil longa, massa reduzida, taxa de descarga baixa e menor toxicidade em relação a outros tipos de baterias (níquel-cád-mio, níquel hidreto metálico), são hoje muito utilizadas em telefones celulares, câmeras fotográficas e outros equipamentos eletroeletrônicos (EEE) portáteis.1,2 O desenvolvimento de novas versões tecnológicas desses equipamentos e a maior facilidade de acesso dos mesmos a mais camadas da população levam a uma inevitável elevação da produção e do consumo de EEE e, consequentemente, de suas baterias. Mais de 60% do mercado da energia potátil é hoje preenchido por baterias de íon-lítio.3-6 Suas características o colocam na dianteira do desenvolvimento de veículos híbridos e elétricos. [6][7][8] Essas baterias apresentam em sua composição um ânodo, um cátodo, coletores de corrente, um separador, um eletrólito, um invó-lucro externo e peças de vedação. O ânodo é composto de grafite, lítio, carbono e fluoreto de polivinilideno (PVDF), que fixa os demais componentes ao coletor de corrente, que é uma lâmina de cobre; o eletrólito é tipicamente hexafluorfosfato de lítio (LiPF 6 ) em solvente orgânico, normalmente carbonato de etileno (CE), carbonato de dietila (DEC), carbonato de dimetila (DMC) ou misturas deles. O separador é feito de polipropileno (PP) ou polietileno (PE). O cátodo é feito de carbono (grafita), um óxido misto contendo lítio e cobalto (como o LiCoO 2 , que detém ~40% do mercado 6 ) e PVDF, que fixa os componentes ao coletor de corrente do cátodo, que é uma lâmina de alumínio. Hoje, cerca de 25% do cobalto produzido no mundo se destina à manufatura de baterias.8 A expansão do mercado de EEE portáteis pressiona o preço desse metal nos mercados internacionais. 9,10Além disso, devido a problemas relacionados à disponibilidade de cobalto (as principais fontes primárias se localizam em regiões de forte instabilidade geopolítica...

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Recovery of platinum from spent catalysts in a fluoride-containing medium

Cited by 47 publications

References 8 publications

PROCESSING OF SPENT ZINC-MnO2 DRY CELLS IN VARIOUS ACIDIC MEDIA

PROCESSING OF SPENT ZINC-MnO2 DRY CELLS IN VARIOUS ACIDIC MEDIA

Oxidation of Coke Formed Over Pt-Al2O3 and Pt-SBA-15 in Propane Dehydrogenation

Lixiviação Ácida De Baterias Íon-Lítio

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