Thermal Upgrading of Nickeliferous Pyrrhotite Tailings for the Recovery of Nickel in the Form of Ferronickel Alloy

Abstract

Production of ferronickel alloy by thermal treatment of nickeliferous pyrrhotite (Pyrr) tailings was studied by both thermodynamic assessment and experimentation. It was demonstrated that Ni can be extracted from Pyrr by increasing the Fe/S ratio of the material, which was achieved by either partial oxidation of Pyrr followed by H 2 reduction or in situ generation of metallic Fe from the reduction of magnetite by petroleum coke pre-mixed with Pyrr. Examination of the samples produced from thermal treatment at 1173 K demonstrated that both approaches were effective in generating ferronickel, although the size of the particles was suboptimal for subsequent separation. Increasing the ferronickel particle size could be achieved by a smelting step at 1473 K, forming a sulfur-deficient molten matte. Slow cooling of the molten matte resulted in precipitation, settling, and growth of ferronickel alloy particles.

Experimental Determination of the Main Parameters of the Refining Process of Rough Ferronickel, Obtained by Iron-Chromium-Nickel Selective Reduction

“…Possible limits of changes in the chemical composition of the initial slag (%) were accepted: CaO=40…50; SiO2=12...18; ΣFeO=20...30; other oxides (A12O3, MgO, etc.)=10...15. The following initial slag composition was chosen: CaO=40%; SiO2=12%; ΣFeO = 20%; other oxides = 20% [15][16][17].…”

Preparation of Ni–Co ore mining mullock powder based cementing materials by mechano-chemical activation: Performance and Mechanism

“…Ni-Co ore mining mullock (OMM) is the waste slag produced after preheating, reduction melting, and separation re ning in the process of nickel mining and smelting (Yu et al 2019). China has more than 80 nickel-cobalt tailings ponds, which can be explained by historical and technical reasons.…”