Impact of MgO and K2O on Slag-Nickel Matte Equilibria

Dmitry Sukhomlinov, Olli Virtanen, Petri Latostenmaa, Ari Jokilaakso, Pekka Taskinen*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

4 Citations (Scopus)
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Slag chemistry of the direct nickel matte smelting was studied in typical industrial high-grade nickel matte smelting conditions at 1400 °C and 0.1 atm pSO2. The experimental technique used involved equilibration, quenching and direct elemental phase composition analysis by Electron Probe X-ray Microanalysis. Magnesia and potassia, a typical gangue constituent of sulfidic nickel concentrates and a common impurity of industrial grade silica flux (sand), respectively, were adopted as slag modifiers in concentrations typical to industrial operations. Their effects on oxidation degree of the nickel-copper-iron matte and equilibrium concentrations of Ni and Cu in the slag were studied as a function of oxygen partial pressure. Solubility of silica in the slag increased significantly with additions of MgO and K2O in the constrained case studied, at silica saturation. Equilibrium concentrations of Ni and Cu in the slag containing MgO and K2O were about a quarter lower compared to the pure iron silicate slag, in the entire oxygen partial pressure range studied.

Original languageEnglish
Pages (from-to)768-778
Number of pages11
Issue number6
Publication statusPublished - 1 Dec 2019
MoE publication typeA1 Journal article-refereed


  • flash smelting
  • fluxing
  • phase equilibria
  • thermodynamics


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