Beneficiation permits recycling of titania-rich pigment sludges

摘要

A study has been conducted to assess a new wet beneficiation treatment for the recovery of the sulphuric-acid-soluble titanium oxide contained in the waste from an Italian TiO{sub}2-pigment facility. The waste is produced during treatment of aTi-enriched slag and contains as main components TiO{sub}2 (54%, of which 42% acid-soluble and 12% insoluble), SiO{sub}2 (27%) and Al{sub}2O{sub}3 (6%). Eighty percent of the material is finer than 50μm. The first step was to ascertain the possibilitiesoffered by size classification, wet gravity separation, froth flotation and wet high-intensity magnetic separation to improve the grade and recovery of TiO{sub}2 and reduce the SiO{sub}2 content. The next step was to optimize the operating conditions ofthe various separations and assemble them into a complete flow-sheet. Beneficiation ensures potentially 70% recovery of the TiO{sub}2 with a concentrate grade of 80%.