XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3137
was reacted for 20 min. The concentration of depressant
was consistent with flotation. The samples were washed
three times with the same pH, and the samples were used
for Raman spectroscopy measurement after dried in a vac-
uum oven.
Adsorption Measurement
The calcium ion concentration in galena and pyrite flota-
tion pulp before and after interaction with different reagents
was measured by ICP (Inductively Coupled Plasma Atomic
Emission Spectrometry). First, 2g mineral samples were
placed in a beaker with distilled water and the pulp was
ultrasonic for 5 min. Then, the supernatant of the ultra-
sonic was poured away and the mineral after ultrasonic
cleaning transferred to the flotation cell and 35ml distilled
water was added. After that, the flotation pulp stirring for 1
min and the pH regulator, Ca2+ of different concentrations
and NaHA were added according to experimental require-
ments, the stirring time of the reagents were 2min,2 min
and 3 min, respectively. After the sample treatment was
completed, the pulp stood for 10min, and the supernatant
was extracted by high speed centrifuge for solid-liquid sepa-
ration. After centrifugation, the Ca2+ concentration in the
supernatant was determined by ICP.
Electrochemical Measurement
The electrochemical test was conducted by using Gamry
Framework (Gamry, America). A three-electrode system
was used for the Tafel polarization curve test, the reference
electrode was saturated Ag/AgCl electrode, the auxiliary
electrode was graphite electrode, and working electrode was
galena or pyrite electrode. Galvanic corrosion potential and
galvanic corrosion current of galvanic corrosion test were
the potential and current of galena and pyrite couples at 20
min. After each test, the mineral surface was polished with
sandpaper for the next test.
RESULTS AND DISCUSSION
Micro-Flotation Results
Figure 2 shows the effect of depressant concentration on
the flotation of galena and pyrite at pH 9. As shown in
Figure 2a and Figure 2b, when the depressant CaCl2 and
NaHA was present alone, the flotation recovery of galena
was little affected. With the increase of depressant concen-
tration, the recovery of galena was above 90%. The float-
ability of pyrite decreased with the increase of CaCl2 and
NaHA concentration. The recovery of pyrite was 66.69%
when the concentration of CaCl2 was 10mg/L and the
recovery of pyrite was 49.6% when the concentration of
CaCl2 was increased to 20mg/L. The recovery of pyrite
first decreased with the increase of NaHA concentration
and then almost remained unchanged. When the concen-
tration of sodium humate was 50mg/L, the recovery of
pyrite decreased from 86.89% to 64.07%, and the recovery
of pyrite changed little with the increase of NaHA con-
centration. The effective separation of galena and pyrite
cannot be achieved with a single depressant. In order to
separate galena and pyrite effectively, the effects of CaCl2
and NaHA as combined depressants on the floatability of
galena and pyrite were studied (Figure 2c and Figure 2d).
As illustrated in Figure 2c, When CaCl2 and NaHA were
added sequentially as combination depressants, both galena
and pyrite had good depression effect. The recoveries of
galena and pyrite remain unchanged after a sharp decrease
with the increase of CaCl2 concentration. The recoveries
of galena and pyrite were 23.12% and 85.34% respec-
tively when CaCl2 concentration was 4mg/L. Galena and
pyrite could be separated effectively under these conditions.
When CaCl2 concentration was continued to increase to
10mg/L, the recovery of galena sharply decreased to below
10%, and the flotation separation of galena and pyrite could
not be realized. Figure 2d illustrated that the recovery of
galena decreased gradually with a small decrease, while the
recovery rate of pyrite decreased greatly with the increase
of NaHA concentration. When NaHA concentration was
50mg/L, the recovery of pyrite decreased to about 20%.
The results shown that galena and pyrite could be separated
effectively when the CaCl2 concentration was 4mg/L and
NaHA concentration was 50mg/L.
The effect pH on the flotation of galena and pyrite
under different reagents is illustrated in Figure 3. As shown
in Figure 3, in the absence of depressant, galena had good
floatability in the whole pH range, and the flotation recov-
ery was above 90% the recovery of pyrite remained above
80% when pH 10 and the recovery of pyrite slightly
decreased when pH 10, which was caused by the OH–
adsorbed on the surface of the mineral to enhance its
hydrophilicity. In the presence of combined depressant,
galena recovery increased first and then decreased with the
increase of pH. Galena flotation recovery was more than
80% in the pH range 6~10. The flotation recovery of pyrite
decreases gradually with the increase of pH. The recovery of
pyrite decreased gradually with the increase of pH and the
flotation recovery of pyrite was about 20% in the pH range
6~10. According to the results, galena and pyrite could be
separated effectively when CaCl2 and NaHA were used as
combination depressants in the pH range 6~10.
The reagents addition order could affect mineral float-
ability. The effect of the reagent addition order of depres-
sants on the flotation of galena and pyrite is studied, and the
was reacted for 20 min. The concentration of depressant
was consistent with flotation. The samples were washed
three times with the same pH, and the samples were used
for Raman spectroscopy measurement after dried in a vac-
uum oven.
Adsorption Measurement
The calcium ion concentration in galena and pyrite flota-
tion pulp before and after interaction with different reagents
was measured by ICP (Inductively Coupled Plasma Atomic
Emission Spectrometry). First, 2g mineral samples were
placed in a beaker with distilled water and the pulp was
ultrasonic for 5 min. Then, the supernatant of the ultra-
sonic was poured away and the mineral after ultrasonic
cleaning transferred to the flotation cell and 35ml distilled
water was added. After that, the flotation pulp stirring for 1
min and the pH regulator, Ca2+ of different concentrations
and NaHA were added according to experimental require-
ments, the stirring time of the reagents were 2min,2 min
and 3 min, respectively. After the sample treatment was
completed, the pulp stood for 10min, and the supernatant
was extracted by high speed centrifuge for solid-liquid sepa-
ration. After centrifugation, the Ca2+ concentration in the
supernatant was determined by ICP.
Electrochemical Measurement
The electrochemical test was conducted by using Gamry
Framework (Gamry, America). A three-electrode system
was used for the Tafel polarization curve test, the reference
electrode was saturated Ag/AgCl electrode, the auxiliary
electrode was graphite electrode, and working electrode was
galena or pyrite electrode. Galvanic corrosion potential and
galvanic corrosion current of galvanic corrosion test were
the potential and current of galena and pyrite couples at 20
min. After each test, the mineral surface was polished with
sandpaper for the next test.
RESULTS AND DISCUSSION
Micro-Flotation Results
Figure 2 shows the effect of depressant concentration on
the flotation of galena and pyrite at pH 9. As shown in
Figure 2a and Figure 2b, when the depressant CaCl2 and
NaHA was present alone, the flotation recovery of galena
was little affected. With the increase of depressant concen-
tration, the recovery of galena was above 90%. The float-
ability of pyrite decreased with the increase of CaCl2 and
NaHA concentration. The recovery of pyrite was 66.69%
when the concentration of CaCl2 was 10mg/L and the
recovery of pyrite was 49.6% when the concentration of
CaCl2 was increased to 20mg/L. The recovery of pyrite
first decreased with the increase of NaHA concentration
and then almost remained unchanged. When the concen-
tration of sodium humate was 50mg/L, the recovery of
pyrite decreased from 86.89% to 64.07%, and the recovery
of pyrite changed little with the increase of NaHA con-
centration. The effective separation of galena and pyrite
cannot be achieved with a single depressant. In order to
separate galena and pyrite effectively, the effects of CaCl2
and NaHA as combined depressants on the floatability of
galena and pyrite were studied (Figure 2c and Figure 2d).
As illustrated in Figure 2c, When CaCl2 and NaHA were
added sequentially as combination depressants, both galena
and pyrite had good depression effect. The recoveries of
galena and pyrite remain unchanged after a sharp decrease
with the increase of CaCl2 concentration. The recoveries
of galena and pyrite were 23.12% and 85.34% respec-
tively when CaCl2 concentration was 4mg/L. Galena and
pyrite could be separated effectively under these conditions.
When CaCl2 concentration was continued to increase to
10mg/L, the recovery of galena sharply decreased to below
10%, and the flotation separation of galena and pyrite could
not be realized. Figure 2d illustrated that the recovery of
galena decreased gradually with a small decrease, while the
recovery rate of pyrite decreased greatly with the increase
of NaHA concentration. When NaHA concentration was
50mg/L, the recovery of pyrite decreased to about 20%.
The results shown that galena and pyrite could be separated
effectively when the CaCl2 concentration was 4mg/L and
NaHA concentration was 50mg/L.
The effect pH on the flotation of galena and pyrite
under different reagents is illustrated in Figure 3. As shown
in Figure 3, in the absence of depressant, galena had good
floatability in the whole pH range, and the flotation recov-
ery was above 90% the recovery of pyrite remained above
80% when pH 10 and the recovery of pyrite slightly
decreased when pH 10, which was caused by the OH–
adsorbed on the surface of the mineral to enhance its
hydrophilicity. In the presence of combined depressant,
galena recovery increased first and then decreased with the
increase of pH. Galena flotation recovery was more than
80% in the pH range 6~10. The flotation recovery of pyrite
decreases gradually with the increase of pH. The recovery of
pyrite decreased gradually with the increase of pH and the
flotation recovery of pyrite was about 20% in the pH range
6~10. According to the results, galena and pyrite could be
separated effectively when CaCl2 and NaHA were used as
combination depressants in the pH range 6~10.
The reagents addition order could affect mineral float-
ability. The effect of the reagent addition order of depres-
sants on the flotation of galena and pyrite is studied, and the