Separation of Manganese and Iron from Reductive Leaching Liquor of Electric Arc Furnace Dust of Ferromanganese Production Units by Solvent Extraction

Electric arc furnace dust (EAFD) of ferromanganese production units, in the form of slurry, contains tar, alkalies, manganese, zinc, iron, silica, calcium, aluminum and other elements. A hydrometallurgical route based on solvent extraction technique was investigated for selective separation of manganese from the dust. Leaching of the EAFD resulted in an aqueous feed containing 4 g/L of manganese and 0.87 g/L iron. At the next stage, extraction of manganese and iron from the leach liquor was performed using D2EHPA, Cyanex 272, Cyanex 302 and their mixtures in various proportions. The synergistic effect of the extractants on the separation of iron and manganese with a mixture of D2EHPA and Cyanex 272 or Cyanex 302 was studied. Increasing the Cyanex 272/ 302 to D2EHPA ratio in the organic phase increased the distance between the extraction isotherms of manganese and Iron. The highest separation factor of iron over manganese was obtained with 15:5% v/v of Cyanex 302: D2EHPA mixture. Effects of various aromatic and aliphatic diluents, such as hexane, kerosene, and carbon tetrachloride on the extraction were also investigated.