4
the pipes feeding the rig. Since observation of relative dif-
ferences between the frothers was the goal, a decision was
taken to do the tests at the finer grind as the trends should
still be the same. Error bars are based on the standard error
of duplicate froth stability tests.
RESULTS AND DISCUSSION
The main aim of the project was to develop a screening
methodology for frothers. The following section will pres-
ent data of both metallurgical bench-scale and plant-scale
tests, as well as laboratory froth stability tests. It will also
draw comparisons between these two types of testing meth-
odologies. Many operations utilise froth stability tests only
to screen frothers before carrying out any flotation test to
determine the metallurgical indicators.
This case study also highlights the natural floatability of
PGMs in the presence of a frother only.
Batch Flotation Testwork
The Merensky ore hot float data obtained on the first con-
centrate is shown in Figures 1 and 2. Figure 1 shows the 4E
PGM concentrate grade versus recovery data and Figure 2
shows the 4E PGM recovery versus concentrate mass pull
data.
As seen from the data, a very different result is observed
when screening frothers with and without other reagents
present. When only adding the frother, Senfroth 200 is the
frother of choice however, in the presence of other reagents
such as collectors and depressants, the frother of choice is
Senfroth 153 when comparing both the 4E PGM concen-
trate grade and recovery (Figure 1). This clearly shows a
varying degree of interactions of the evaluated frothers with
the other reagents and the minerals present in the ore. It is
interesting to note that the natural floatability of the PGM
minerals present in the Merensky ore with only a frother is
around 16% 4E PGM while with other reagents including
the frothers the average 4E PGM recovery is around 87%
4E PGM.
The 4E PGM recovery versus concentrate mass pull
data shows that a lower mass pull and a higher 4E PGM
recovery were obtained for Senfroth 153 with other reagents
present compared to the baseline (Figure 2).
Figure 3 shows the first concentrate mass pull data,
which indicates that Senkol 153 gave the lowest mass pull,
compared to the other frothers evaluated yet still giving the
highest total 4E PGM recovery, thereby offering selectivity
with lower dilution of the concentrate by gangue minerals.
Once the frother was selected from the data obtained
during the initial phase of the testwork, the collector dosage
was optimised using Senfroth 153 as the optimal frother.
Figure 4 shows the dosage curve obtained for SIBX. The
data highlights that a dosage of 215 g/t is the optimal dos-
age and coincides with the operations current SIBX dosage.
Figure 1. 4E PGM concentrate grade-recovery data obtained during a Merensky ore hot float
screening of frothers with and without other reagents
the pipes feeding the rig. Since observation of relative dif-
ferences between the frothers was the goal, a decision was
taken to do the tests at the finer grind as the trends should
still be the same. Error bars are based on the standard error
of duplicate froth stability tests.
RESULTS AND DISCUSSION
The main aim of the project was to develop a screening
methodology for frothers. The following section will pres-
ent data of both metallurgical bench-scale and plant-scale
tests, as well as laboratory froth stability tests. It will also
draw comparisons between these two types of testing meth-
odologies. Many operations utilise froth stability tests only
to screen frothers before carrying out any flotation test to
determine the metallurgical indicators.
This case study also highlights the natural floatability of
PGMs in the presence of a frother only.
Batch Flotation Testwork
The Merensky ore hot float data obtained on the first con-
centrate is shown in Figures 1 and 2. Figure 1 shows the 4E
PGM concentrate grade versus recovery data and Figure 2
shows the 4E PGM recovery versus concentrate mass pull
data.
As seen from the data, a very different result is observed
when screening frothers with and without other reagents
present. When only adding the frother, Senfroth 200 is the
frother of choice however, in the presence of other reagents
such as collectors and depressants, the frother of choice is
Senfroth 153 when comparing both the 4E PGM concen-
trate grade and recovery (Figure 1). This clearly shows a
varying degree of interactions of the evaluated frothers with
the other reagents and the minerals present in the ore. It is
interesting to note that the natural floatability of the PGM
minerals present in the Merensky ore with only a frother is
around 16% 4E PGM while with other reagents including
the frothers the average 4E PGM recovery is around 87%
4E PGM.
The 4E PGM recovery versus concentrate mass pull
data shows that a lower mass pull and a higher 4E PGM
recovery were obtained for Senfroth 153 with other reagents
present compared to the baseline (Figure 2).
Figure 3 shows the first concentrate mass pull data,
which indicates that Senkol 153 gave the lowest mass pull,
compared to the other frothers evaluated yet still giving the
highest total 4E PGM recovery, thereby offering selectivity
with lower dilution of the concentrate by gangue minerals.
Once the frother was selected from the data obtained
during the initial phase of the testwork, the collector dosage
was optimised using Senfroth 153 as the optimal frother.
Figure 4 shows the dosage curve obtained for SIBX. The
data highlights that a dosage of 215 g/t is the optimal dos-
age and coincides with the operations current SIBX dosage.
Figure 1. 4E PGM concentrate grade-recovery data obtained during a Merensky ore hot float
screening of frothers with and without other reagents