Processing of spent NiW/Al2O3 catalysts

Autor: Jéssica Frontino Paulino, Julio Carlos Afonso, José Waldemar Silva Dias da Cunha

Publikováno v: Química Nova, Vol 36, Iss 5, Pp 711-715 (2013)

Spent oxidized (500 ºC, 5 h) commercial NiW/Al2O3 catalysts were processed using two different routes: a) fusion with NaOH (650 ºC, 1 h), the roasted mass was leached in water; b) leaching with HCl or H2SO4 (70 ºC, 1-3 h). HCl was the best leachan

Externí odkaz: https://doaj.org/article/b2cfbefbe4d84a17baff02e6d2df3b32

Extração líquido-líquido de ferro(III) e titânio(IV) pelo ácido bis-(2-etil-hexil) fosfórico (D2EHPA) em meio de ácido sulfúrico Liquid-liquid extraction (LLE) of Fe(III) and Ti(IV) by bis-(2-ethyl-hexyl) phosphoric acid (D2EHPA) in sulfuric acid medium

Autor: Glauco Corrêa da Silva, José Waldemar Silva Dias da Cunha, Jo Dweck, Julio Carlos Afonso

Publikováno v: Química Nova, Vol 31, Iss 5, Pp 1230-1236 (2008)

This work presents a study on the separation of Fe(III) and Ti(IV) from sulfuric acid leaching solutions of ilmenite (FeTiO3) using liquid-liquid extraction with D2EHPA in n-dodecane as extracting agent. The distribution coefficients (K D) of the ele

Externí odkaz: https://doaj.org/article/240fcdb1041541a99fa40aa50aa03593

Extração líquido-líquido de urânio(VI) do colofanito de itataia (Santa Quitéria, Ceará) por extratantes orgânicos em presença de ácido fosfórico Liquid-liquid extraction of uranium(VI) from colofanite of itataia (Santa Quitéria, Ceará) by organic extractants in the presence of phosphoric acid

Autor: Valeria Aparecida Leitão Ribeiro, Júlio Carlos Afonso, Glória Regina da Silva Wildhagen, José Waldemar Silva Dias da Cunha

Publikováno v: Química Nova, Vol 31, Iss 8, Pp 2159-2164 (2008)

This work describes the liquid-liquid extraction of uranium after digestion of colofanite (a fluoroapatite) from Itataia with sulfuric acid. The experiments were run at room temperature in one stage. Among the solutions tested the highest distributio

Externí odkaz: https://doaj.org/article/029497c87db9420cabf3650c66fa9dc2

Processing of spent NiW/Al2O3 catalysts

Autor: Júlio Carlos Afonso, Jéssica Frontino Paulino, José Waldemar Silva Dias da Cunha

Publikováno v: Química Nova, Vol 36, Iss 5, Pp 711-715 (2013)
Química Nova v.36 n.5 2013
Química Nova
Sociedade Brasileira de Química (SBQ)
instacron:SBQ
Química Nova, Volume: 36, Issue: 5, Pages: 711-715, Published: 2013

Spent oxidized (500 ºC, 5 h) commercial NiW/Al2O3 catalysts were processed using two different routes: a) fusion with NaOH (650 ºC, 1 h), the roasted mass was leached in water; b) leaching with HCl or H2SO4 (70 ºC, 1-3 h). HCl was the best leachan

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::906476a50689e34deab0c98d4ddeaebc
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422013000500016&lng=en&tlng=en

Isolamento do tungstênio da volframita da mina de Igarapé Manteiga (Rondônia - Brasil) por lixiviação ácida

Autor: José Waldemar Silva Dias da Cunha, Cláudio Augusto Vianna, José Luiz Mantovano, Júlio Carlos Afonso, Jéssica Frontino Paulino

Publikováno v: Química Nova, Vol 35, Iss 9, Pp 1854-1857 (2012)

We report results of the efficiency of tungsten extraction from wolframite concentrate (containing 61.5 wt % WO3) from the Igarapé Manteiga mine (state of Rondônia, Brazil) through acid leaching with strong mineral acids at 100 ºC and 400 rpm for

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5069f67fe6f97eb4869a5274fcf508c1
https://doi.org/10.1590/s0100-40422012000900026