396
J. Salminen et al.
Fig. 4 Principle of ScanArc’s plasma torch
Fig. 5 Principles of ScanArc and ArcFume plasma reactor
turbulence to the liquid slag and an upper smaller PG2 (200 kW) that helps to keep
the heat balance of the reactor and helps the kinetics of the reactions. Air/LPG = 27
was typically used in the test work (Fig. 5).
Smelting Tests of Boliden Kokkola Residues Using ArcFume
Plasma Reactor
The idea of testing combined residue as a feed was first seen as risky and challenging.
The main foreseen risk lied in the slightly unknown dynamics of sulphur vaporization
and reactions in the plasma furnace and unwanted solidification of sulphur in the offgas lines. Tests were first carried out with jarosite after flotation that still contained
significant amounts of sulphur. Good clean slag was produced with flotated jarosite,
and no matte (FeS) formation was observed. That gave confidence using combined
residue as a feed into plasma reactor. The results shown in this work looks promising,
and as an outcome, one can state that the ArcFume plasma process can handle the
most difficult feeds such as Boliden Kokkola’s combined residue.
Figure 6 shows the preliminary idea for the smelting and fuming process. Com-
J. Salminen et al.
Fig. 4 Principle of ScanArc’s plasma torch
Fig. 5 Principles of ScanArc and ArcFume plasma reactor
turbulence to the liquid slag and an upper smaller PG2 (200 kW) that helps to keep
the heat balance of the reactor and helps the kinetics of the reactions. Air/LPG = 27
was typically used in the test work (Fig. 5).
Smelting Tests of Boliden Kokkola Residues Using ArcFume
Plasma Reactor
The idea of testing combined residue as a feed was first seen as risky and challenging.
The main foreseen risk lied in the slightly unknown dynamics of sulphur vaporization
and reactions in the plasma furnace and unwanted solidification of sulphur in the offgas lines. Tests were first carried out with jarosite after flotation that still contained
significant amounts of sulphur. Good clean slag was produced with flotated jarosite,
and no matte (FeS) formation was observed. That gave confidence using combined
residue as a feed into plasma reactor. The results shown in this work looks promising,
and as an outcome, one can state that the ArcFume plasma process can handle the
most difficult feeds such as Boliden Kokkola’s combined residue.
Figure 6 shows the preliminary idea for the smelting and fuming process. Com-