XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2255
The recovery of mixed sulfides was 2 to 4% higher at 35 °C
in comparison to that achieved at 20 °C. As a result, cumu-
lative copper recovery (rougher and scavenger) increased
markedly when slag flotation was carried out at 35 °C in
comparison to 20 °C option. Cu grade of approximately
3% higher has been registered for the tests performed at 35
°C, compared to the one at 20 °C, implying positive effect
from temperature on froth carrying capacity. This trend
also means that oxygen content in the pulp plays a subordi-
nate role in the floatability of copper bearing phases in the
investigated slag material.
Increased temperature possibly stimulate release of
Cu cations into the pulp which could facilitate collector
adsorption on mineral surface. On a more fundamental
side, it could be studied whether chemisorption or physical
sorption of the collector is the predominant mechanism for
the two Cu-bearing phases identified in the slags.
Based on the liberation curves derived from the SEM-
EDS it could be assumed that the (re)-grinding stimulates
merely surface reactivation of slag particles rather than real
fragmentation and size reduction.
with approximately 7% higher recovery observed at 35 °C,
compared to the one seen at 15 °C. Based on the latter
observations, it could be reconfirmed that higher tempera-
tures do favor slag flotation kinetics.
The recoveries and grades of silicon, (proxy of fayalite)
demonstrate a well-defined increasing trend with tem-
perature increase – Figure 10. This trend corroborates the
higher mass pull during high temperature flotation, which
together with the higher recoveries of Cu, is possibly leading
to an elevated Si-content inside the concentrate. However,
this can be an indication of more fayalite being recovered
into the concentrate, knowing that fayalite is not the com-
pound of economic value. It should be noted however that
to maintain smelter process efficiency the recycled to the
furnace concentrate should carry fayalite to a certain extent.
CONCLUSIONS
Higher temperatures seemed to have a positive impact
on pulp viscosity and possible collector adsorption on the
copper-bearing sulfides present in the slag, while has limited
or no influence when native copper phases are concerned.
Figure 9. Cu grade (left) and cumulative recovery (right) at rougher and scavenger stages as function of temperature
Figure 10. Cumulative Si grades and recoveries at rougher and scavenger stages as function of temperature
The recovery of mixed sulfides was 2 to 4% higher at 35 °C
in comparison to that achieved at 20 °C. As a result, cumu-
lative copper recovery (rougher and scavenger) increased
markedly when slag flotation was carried out at 35 °C in
comparison to 20 °C option. Cu grade of approximately
3% higher has been registered for the tests performed at 35
°C, compared to the one at 20 °C, implying positive effect
from temperature on froth carrying capacity. This trend
also means that oxygen content in the pulp plays a subordi-
nate role in the floatability of copper bearing phases in the
investigated slag material.
Increased temperature possibly stimulate release of
Cu cations into the pulp which could facilitate collector
adsorption on mineral surface. On a more fundamental
side, it could be studied whether chemisorption or physical
sorption of the collector is the predominant mechanism for
the two Cu-bearing phases identified in the slags.
Based on the liberation curves derived from the SEM-
EDS it could be assumed that the (re)-grinding stimulates
merely surface reactivation of slag particles rather than real
fragmentation and size reduction.
with approximately 7% higher recovery observed at 35 °C,
compared to the one seen at 15 °C. Based on the latter
observations, it could be reconfirmed that higher tempera-
tures do favor slag flotation kinetics.
The recoveries and grades of silicon, (proxy of fayalite)
demonstrate a well-defined increasing trend with tem-
perature increase – Figure 10. This trend corroborates the
higher mass pull during high temperature flotation, which
together with the higher recoveries of Cu, is possibly leading
to an elevated Si-content inside the concentrate. However,
this can be an indication of more fayalite being recovered
into the concentrate, knowing that fayalite is not the com-
pound of economic value. It should be noted however that
to maintain smelter process efficiency the recycled to the
furnace concentrate should carry fayalite to a certain extent.
CONCLUSIONS
Higher temperatures seemed to have a positive impact
on pulp viscosity and possible collector adsorption on the
copper-bearing sulfides present in the slag, while has limited
or no influence when native copper phases are concerned.
Figure 9. Cu grade (left) and cumulative recovery (right) at rougher and scavenger stages as function of temperature
Figure 10. Cumulative Si grades and recoveries at rougher and scavenger stages as function of temperature