Method for improving iron grade of magnetic separation iron concentrate from copper benefication tailings of copper smelting slag

Abstract

The invention discloses a method for improving the iron grade of magnetic separation iron concentrate from copper beneficiation tailings of copper smelting slag, relating to the fields of hydrometallurgy and comprehensive recovery of secondary resources. The invention leaches the copper beneficiation tailings of copper smelting slag with a sulfuric acid solution, filters the leached material to collect leaching residue, and performs grinding treatment on the leaching residue followed by magnetic separation to obtain an iron concentrate product; the concentration of the sulfuric acid solution used ranges from 0.1 mol / L to 0.4 mol / L. Based on the difference in acid decomposition between fayalite and magnetite, the invention adopts a selective acid leaching process combined with grinding and magnetic separation procedures: it directionally decomposes fayalite through acid leaching to create conditions for subsequent magnetite enrichment; then breaks the intergrowth structure between magnetite, gangue minerals and undecomposed fayalite by grinding; and finally realizes efficient separation of magnetite by means of magnetic separation, significantly improving the grade and recovery rate of iron concentrate. The invention features simple operation, can meet the demand for iron resource recovery from copper smelting solid waste, and provides a feasible path for the high-value utilization of secondary resources.