Re-manufacture of cobalt-manganese-bromide as a liquid catalyst from spent catalyst containing cobalt generated from petrochemical processes via hydrometallurgy

[Display omitted] •A spent CMB catalyst was completely leached at 1M H2SO4, 40°C and 0.1 of S/L ratio.•The S×F value of Co and Mn over Ca and Mg was higher than 11 by Na-Cyanex 272.•Co and Mn was recovered from Ca and Mg through 4 stage extraction by Na-Cayenx 272.•Re-manufactured CMB contains 48.5g/L Co and 23.2g/L Mn by 2M HBr in stripping.•In pilot plant, 288L CMB liquid catalyst could be produced during 24h. Cobalt and manganese have been the subject of individual separation studies because their fields of application are different. However, this study shows that high-value products can be manufactured in the form of a cobalt-manganese-bromide (CMB) liquid catalyst by simultaneously recovering cobalt and manganese. Na-bis-(2,4,4-tri-methyl-pentyl)phosphinic acid was employed in order to manufacture the CMB liquid catalyst from the spent catalyst generated from petroleum chemistry processes. The pH-isotherm, degree of saponification of solvent and separation factor values were investigated. ΔpH50 and separation factor values show that Co and Mn can be separated from impurities such as Mg and Ca. Further, the extraction stages and organic/aqueous ratio isotherms were investigated using counter-current simulation extraction batch tests. To prepare CMB from a loaded organic phase obtained in a stripping study using hydrogen bromide, the Co and Mn were completely stripped and concentrated by a factor of 6 using a 2M hydrogen bromide solution. When compared with manufactured and commercial CMB, the CMB liquid catalyst could be produced by supplying a shortage of Mn in the form of manganese bromide. Finally, the method of manufacture of CMB was subjected to a real pilot plant test.