Recovery of iron from dry tailings dump of a processing plant using an efficient circuit

More than half of the tailings dams worldwide contain valuable materials due to the poor performance of upstream processes. Iron ore processing plants are no exception and there has been always a transfer of iron to the tailings. This work aims to investigate the feasibility of producing a high yield product suitable for feed of the concentrate plant from the tailings dump of Zarand Steel Complex ore. For this purpose, five dumps with Fe average grade of 17-20% were studied and sampled. Six samples from each of the five dumps together with one sample from the mixture of them were taken. The representative samples were crushed by a roll crusher down to 6 mm and followed by a medium intensity magnetic separator (MIMS) and a rougher stage. The tailing of previous steps was removed and the product was concentrated by a low intensity magnetic separator (LIMS) in the cleaner stage. The product obtained was sieved by a 3 mm screen that the underflow was selected as the final product while its coarse-grained fraction was crushed by a roll crusher at the beginning of the circuit.
Experimental results showed that the iron reprocessing from tailings dumps was potentially associated with an increase of 20-25% in the iron content. The mass recovery obtained from each dump sample comprised of ca. 16- 22% with the iron grade of 40-45%. The mass recovery of the mixed dumps sample was about 20% with an average grade of 40%.