Sample records for hydrogen sulfates

Sample records 1 - 1 shown.


Recuperação de metais de catalisadores de hidrorrefino usados via fusão com KHSO4/ Recovery of elements from spent hydrorefining catalysts after fusion with KHSO4

Afonso, Julio Carlos; Silva, Neocir da; Salvato, Gustavo Nascimento; Busnardo, Roberto Giovanini

Resumo em inglês This work describes a process for metal recovery from spent NiMo and CoMo/Al2O3 commercial hydrorefining catalysts. The samples were treated by fusion with potassium hydrogen sulfate (5 h, 600 ºC) with a KHSO4/catalyst mass ratio of 10:1. After fusion the solid was solubilized in water (100 ºC), leaving silicon compounds as residue. Losses of nickel and cobalt may reach 16 wt% of the amount present in the sample, depending on the silicon content. Soluble metals were iso (mais) lated by selective precipitation techniques (nickel, cobalt, aluminum) or by solvent extraction with methyl-isobutyl ketone (molybdenum) in a hydrochloric acid medium. All metals were recovered in very good yields except for nickel and cobalt in the presence of considerable amounts of silicon. Soluble wastes consist of potassium/sodium sulfates/chlorides. Solid wastes correspond to about 4 wt% of the catalyst and can be discarded in industrial dumps.

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