Abstract

XIANG, X.; WANG, X.; XIA, W.  and  YIN, J.. Metal recovery from TiCl₄ slurry by evaporation and acid leaching. J. S. Afr. Inst. Min. Metall. [online]. 2019, vol.119, n.5, pp.421-426. ISSN 2411-9717.  http://dx.doi.org/10.17159/2411-9717/85-192-1/2019.

TiCl₄ slurry containing valuable metals is an unavoidable by-product of the titanium ore chlorination process. The recovery of these valuable metals, which include titanium, niobium, tantalum, and aluminum, is an urgent issue to tackle in the titanium industry. The results of this investigation show that the valuable metallic elements can be recovered from the slurry by evaporation in a sealed container and leaching with dilute hydrochloric acid. After evaporation at 200°C for 60 minutes, nearly 99% of the titanium was recovered in the form of TiCl₄, which was formed by the reaction of the TiO₂ in the slurry with AlCl₃. After evaporation, metals like niobium, aluminum, and tantalum remained in the residue. By leaching with 2.1 mol/L HCl at a L/S ratio of 6:1 mL/g at 80°C for 60 minutes, the soluble metals, such as aluminum, iron, and copper were all removed from the residue, and the niobium and tantalum were further enriched in the leach residue. A concentrate containing 53.40 wt% Nb and 5.57 wt% Ta was obtained by washing the leach residue with dilute aqueous ammonia under stirring. A potential waste water purifying agent containing 263.75 g/L AlCl₃ was produced by purifying the leaching solution with Al(OH)₃ and modified polyacrylamide.

Keywords : TiCl₄ slurry; niobium; recovery; evaporation; leaching.

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