Abstract: By analyzing the mineral composition and phase composition of electric furnace nickel-iron slag, the heavy metal content of electric furnace nickel-iron slag with different particle sizes was investigated, and the BCR (Bureau Community of Reference) continuous extraction method and adjusting the pH value of extractant were used to test the leaching of electric furnace nickel-iron slag. The results show that the powdered electric furnace nickel-iron slag has the highest heavy metal content, and the complete electric furnace nickel-iron slag has a lower heavy metal content than that of the damaged. The electric furnace nickel-iron slag is a general industrial waste, not a hazardous waste. Heavy metal Cd is more easily leached, heavy metals Cu and Ni are more easily leached in a weak acid environment, heavy metals Cr, Pb and Mn are more easily leached in a reducible state, and Zn and Cu are more easily leached in an oxidizable state. Except for Cu and Pb, the decrease of pH increases the leaching amount of heavy metals in the nickel-iron slag of electric furnace, showing an L-shaped leaching curve. Cu accelerates the leaching in an alkaline environment, while Pb only is leached in a large amount under a strong alkaline environment. Pay attention to the Pb leaching test in a strong alkaline environment.

Key words: nickel-iron slag, heavy metal, leaching toxicity, BCR, electric furnace