flotation behaviour of upper east and lower mine ores
TRANSCRIPT
Investigation Of Flotation Behaviour Of Upper East And
Lower Mine Ores At Bulyanhulu Gold Plant
By:Emmanuel E. Mmole
IPT Student - University of Dar es Salaam
Outline
• Introduction
• Project Objectives
•Methodology
• Results
• Conclusion
• Recommendations
Introduction• The flotation ore feed at Bulyanhulu gold processing plant has a
complex mineralogy
• It is mainly comprised of pyrite (FeS2) and chalcopyrite (CuFeS2)
• The ore feed includes the Lower Mine (high grade) and the
Upper East (low grade) ores.
• This feed causes pulp spillages at the cleaner flotation cells due
to its probable mineralogy and flotation characteristics
Project Objectives• To optimize the production of gold, copper and silver at the
flotation circuit by determining the flotation behavior of the
Lower Mine and Upper East ores
• Improving gold (and copper) recovery with the subsequent
reduction of gold losses in tails
• Optimizing the flotation feed treatment
• Reduction of operating costs
Methodology• Kinetic flotation testwork on the Lower mine and Upper East
ore samples, as well as the flotation feed as the control sample.
• Pulp density: 35% solids
• Air flowrate: 5 L/min
• pH: Natural ore pH (8 - 9)
• Reagents dosages:
PRODUCT PAX (g/t) Aerophine (g/t) Frother (g/t)
Flotation feed 300 22 27Lower Mine Ore 300 22 27Upper East Ore 600 50 27
Results
0 5 10 15 20 25 30 350.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
0.00
39.33
62.84
75.2078.01 78.91 80.37
82.91
0.00
68.39
79.02
86.22 87.37 88.14 88.88 90.10
0.00
62.94
81.58
89.78 90.96 91.65 92.70 93.64
Au recovery vs time curves for Lower Mine ore, Upper East ore and Flotation feed
Lower Mine Ore Upper East Ore Flotation Feed
Flotation Time (min)
% A
u Re
cove
ry
Results (cont.)
0 5 10 15 20 25 30 350.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
0.00
48.27
72.95
86.2888.75 89.55 90.65 92.11
0.00
59.08
68.59
76.3278.50
81.6583.91
87.74
0.00
66.29
82.00
89.01 90.23 90.98 92.00 92.89
Cu recovery vs time curves for Lower Mine ore, Upper East ore and Flotation feed
Lower Mine Ore Upper East Ore Flotation Feed
Flotation Time (min)
% C
u Re
cove
ry
Results (cont.)
150 225 300 375 450 5250.00
20.00
40.00
60.00
80.00
100.00
10.00
15.00
20.00
25.00
30.00Au Recovery vs PAX dosage for Flotation feed
Au Recovery Logarithmic (Au Recovery) Au grade Polynomial (Au grade)
PAX dosage (g/t)
Au re
cove
ry (%
)
Au g
rade
(g/t
)
Results (cont.)
150 225 300 375 450 52580.00
85.00
90.00
95.00
100.00
0.000
5.000
10.000
15.000
20.000
Cu Recovery vs PAX dosage for Flotation feed
PAX dosage (g/t)
Cu re
cove
ry (%
)
Cu g
rade
(%)
Conclusion• Flotability of gold and copper bearing minerals in both types of
ores is relatively fast. At least 70% of these minerals can be
recovered in the first 10 minutes of flotation after which the rate
of flotation starts to decrease.
• The recovery curve of PAX optimization for copper seems to
flatten at around 300 g/t PAX with a recovery of about 95% and
concentrate grade around 3%.
• For gold, the recovery keeps increasing past 300 g/t PAX giving
recovery of about 81% and a concentrate grade of 25 g/t.
Recommendations• The project is commendable because it would help to:
Alleviate additional costs incurred due to usage of excessive
reagents to treat the troublesome ore feed.
Optimize the flotation feed treatment, thereby improving the
flotation circuit recovery (and concentrate grade).
Recommendations (cont.)• I therefore recommend the following:
Mineralogical analysis of the flotation feed should be done.
Decrease the amount of Upper East ore in the composite
flotation feed.
Further tests should be done by a proper design of
experiment so as to determine the interaction of the reagents
on the response (recovery or concentrate grade).