2440 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
A further test was carried out doubling the dose of
the dithiophosphate to see if the copper recovery could be
improved with nickel recovery staying the same. The results
proved that doubling the dose was beyond the starvation
levels, allowing nickel to float. Copper recoveries went
up to better than SIPX recoveries to 53.5%, 74.3% and
87.1%.
Being that Eagle doesn’t have the ability to test a grind
addition type reagent in its pilot plant, adding thionocarba-
mate by itself is not an option. However, the reagent can be
easily dispersed when added with a water-soluble reagent,
like xanthate and dithiophosphates. There are many reagent
flotation products on the market involving thionocarba-
mate/dithiophosphate blends. Further lab tests will involv-
ing find a good blend of these two reagents.
CONCLUSIONS
The conventional flotation circuit for nickel/copper ores
predates the discovery of copper selective collectors that
have been applied in copper circuits since the 1960s, mak-
ing cleaner copper concentrates free from gangue sulphide
minerals. However, these reagents, when applied properly,
can also provide recovery and grade efficiencies wherever
copper minerals are, regardless of the circuit. Copper min-
erals have the strongest flotation kinetics of any other min-
eral, and using copper selective reagents can lead to better
results with nickel ores.
The end result for the Eagle flotation circuit is not to
remove a majority of the copper mineral in the first flota-
tion cell, but to take enough away to enhance the nickel flo-
tation kinetics in the rest of the circuit. With that in mind,
it will be possible to maintain a starvation dose of a copper
selective reagent which will not pull a significant amount
of nickel.
FUTURE WORK
More lab tests are scheduled. With the thionocarbamate
reagent requiring addition to the grinding mill, it will not
be possible to trial the reagent in our pilot plant. With
the dithiophosphate showing promise as well, dithiophos-
phate/thionocarbamate blends will be tested in the lab to
facilitate dosing right into the feed box of the pilot plant.
Also, the current diethyl dithiophosphate will be tested
against a dibutyl dithiophosphate to see if the larger mole-
cule enhances copper recovery and ignores nickel minerals.
Once a suitable reagent or blend of thionocarbamate/
dithiophosphate is determined, trials in the mill’s pilot
plant will be undertaken.
ACKNOWLEDGMENTS
The author would like to thank the management of Eagle
Mine and Lundin Mining for supporting the research pre-
sented in this paper.
REFERENCES
Lawson, V., G Hill, G., Kormos, L., and G Marrs, G. 2014.
The Separation of Pentlandite from Chalcopyrite,
Pyrrhotite and Gangue in Nickel Projects Throughout
the World. Proceedings of the 12th AUSIMM Mill
Operators’ Conference, Townsville, Queensland.
Brindle, S. 2022. Eagle June 2022 -Composite Mineralogy
Survey. XPS Expert Process Solutions, Report No.
5022833. Falconbridge, Ontario.
Capanema, R., ed. 2009. Mineral Chemicals Handbook.
Stanford, CT. Cytec Industries Inc.
Agar, G E, Kipkie, W B and Wells, P F, 1982. The separa-
tion of chalcopyrite from pentlandite from INCO met-
als Sudbury area ores, in Proceedings XIV International
Mineral Processing Conference, paper IV-1 (Canadian
Institute of Mining and Metallurgy: Toronto).
Xu, M and Wells, P, 2004. Development of copper/nickel
separation at INCO, in Proceedings 36th Annual
Meeting of the Canadian Mineral Processors, Ottawa, pp
15–28.
Fuerstenau, M C, Jameson, G J and Yoon, R H, 2007.
Froth Flotation: A Century of Innovation, pp 806–
808 (Society for Mining, Metallurgy and Exploration:
Englewood).
Lawson, V and Rowland, L, 2012. Copper nickel sepa-
ration, in Proceedings XXVI International Mineral
Processing Congress, paper 1080 (Indian Institute of
Minerals Engineers: New Delhi).
A further test was carried out doubling the dose of
the dithiophosphate to see if the copper recovery could be
improved with nickel recovery staying the same. The results
proved that doubling the dose was beyond the starvation
levels, allowing nickel to float. Copper recoveries went
up to better than SIPX recoveries to 53.5%, 74.3% and
87.1%.
Being that Eagle doesn’t have the ability to test a grind
addition type reagent in its pilot plant, adding thionocarba-
mate by itself is not an option. However, the reagent can be
easily dispersed when added with a water-soluble reagent,
like xanthate and dithiophosphates. There are many reagent
flotation products on the market involving thionocarba-
mate/dithiophosphate blends. Further lab tests will involv-
ing find a good blend of these two reagents.
CONCLUSIONS
The conventional flotation circuit for nickel/copper ores
predates the discovery of copper selective collectors that
have been applied in copper circuits since the 1960s, mak-
ing cleaner copper concentrates free from gangue sulphide
minerals. However, these reagents, when applied properly,
can also provide recovery and grade efficiencies wherever
copper minerals are, regardless of the circuit. Copper min-
erals have the strongest flotation kinetics of any other min-
eral, and using copper selective reagents can lead to better
results with nickel ores.
The end result for the Eagle flotation circuit is not to
remove a majority of the copper mineral in the first flota-
tion cell, but to take enough away to enhance the nickel flo-
tation kinetics in the rest of the circuit. With that in mind,
it will be possible to maintain a starvation dose of a copper
selective reagent which will not pull a significant amount
of nickel.
FUTURE WORK
More lab tests are scheduled. With the thionocarbamate
reagent requiring addition to the grinding mill, it will not
be possible to trial the reagent in our pilot plant. With
the dithiophosphate showing promise as well, dithiophos-
phate/thionocarbamate blends will be tested in the lab to
facilitate dosing right into the feed box of the pilot plant.
Also, the current diethyl dithiophosphate will be tested
against a dibutyl dithiophosphate to see if the larger mole-
cule enhances copper recovery and ignores nickel minerals.
Once a suitable reagent or blend of thionocarbamate/
dithiophosphate is determined, trials in the mill’s pilot
plant will be undertaken.
ACKNOWLEDGMENTS
The author would like to thank the management of Eagle
Mine and Lundin Mining for supporting the research pre-
sented in this paper.
REFERENCES
Lawson, V., G Hill, G., Kormos, L., and G Marrs, G. 2014.
The Separation of Pentlandite from Chalcopyrite,
Pyrrhotite and Gangue in Nickel Projects Throughout
the World. Proceedings of the 12th AUSIMM Mill
Operators’ Conference, Townsville, Queensland.
Brindle, S. 2022. Eagle June 2022 -Composite Mineralogy
Survey. XPS Expert Process Solutions, Report No.
5022833. Falconbridge, Ontario.
Capanema, R., ed. 2009. Mineral Chemicals Handbook.
Stanford, CT. Cytec Industries Inc.
Agar, G E, Kipkie, W B and Wells, P F, 1982. The separa-
tion of chalcopyrite from pentlandite from INCO met-
als Sudbury area ores, in Proceedings XIV International
Mineral Processing Conference, paper IV-1 (Canadian
Institute of Mining and Metallurgy: Toronto).
Xu, M and Wells, P, 2004. Development of copper/nickel
separation at INCO, in Proceedings 36th Annual
Meeting of the Canadian Mineral Processors, Ottawa, pp
15–28.
Fuerstenau, M C, Jameson, G J and Yoon, R H, 2007.
Froth Flotation: A Century of Innovation, pp 806–
808 (Society for Mining, Metallurgy and Exploration:
Englewood).
Lawson, V and Rowland, L, 2012. Copper nickel sepa-
ration, in Proceedings XXVI International Mineral
Processing Congress, paper 1080 (Indian Institute of
Minerals Engineers: New Delhi).