Separation and recovery of iron from vanadium extraction tailing slag by P204-P507 mixture collector flotation process

Vanadium extraction tailing slag is difficult to be utilized on a large scale due to their complex mineral composition. A promising collector was proposed to separate iron and gypsum from the vanadium extraction tailing slag with mixed collector of bis(2-ethylhexyl) phosphate and Mono-(2-ethylhexyl) phosphate by flotation process. The vanadium extraction tailing slag mainly consist of iron oxide, ilmenite, vanadium iron spinel, calcium sulfate and quartz. Under the conditions of pulp pH of 1, ball mill time of 1.5 h, collector ratio of 1:1, pulp concentration of 14.29 g/L, and collector dosage of 2.86 mL/L, content of TFe (total iron) in the vanadium extraction tailing slag increased from 27.5 % to 37.13 %. By seven times flotation processes, TFe content of flotation concentrate can increase to 43.27 % and the flotation tailing can be used as gypsum production. The interaction mechanism between (P204 + P507) collector and vanadium extraction tailing slag was analyzed by XRD, Zeta potential, FTIR and XPS. This method realizes the recovery of iron and gypsum from vanadium extraction tailing slag, and improves the resource utilization efficiency of solid waste residue. • Recovery of iron and gypsum from vanadium tailing slag by flotation method. • A mixed collector of P204 and P507 was proposed. • Iron grade can increase to 43.27 % by multi-flotation processes. • The flotation tailing can be used as gypsum.