3063
Enhancing Gold-Tellurium Flotation Performance: A Study from
Laboratory to Industrial Scale on Åkulla Kankberg Ore at the
Boliden Plant
Carmel Vasconcelos, Anna Gulkova, Dominiqui Brising, Paulina Nordfeldt
Boliden Minerals
ABSTRACT: Au-Te mineralization is contained within quartz-andalusite and topaz alteration, with small
amounts of sulphide minerals. Gold is present in the ore as native gold and gold-tellurides. The flotation plant
aims to selectively float gold mineral particles to maximize production. This research presents the findings of
recovery and selectivity enhancements for gold, silver and tellurium at both laboratory and industrial scales by
substituting the main flotation collector. Quantification of the differences in metallurgical performance between
the collectors was evaluated, and quantified mineralogical characterization using QEMSCAN ® was done to
understand the process responses.
INTRODUCTION
Gold primarily occurs in its native form and secondarily as
gold in solid-solution, mainly in compounds with silver,
tellurium, and mercury (Zhang 2010). Au-Tellurium min-
eralization exhibits significant variation and can commonly
be classified into mineral member groups with silver, bis-
muth, and lead (Spory 2019). Generally, Au-tellurides are
processed with sulphide minerals, with recovery occurring
in the concentrate along with pyrite and other sulphides
(Yan, 1997).
The metallurgical process chain for complex miner-
als often involves flotation, leaching, and advanced smelt-
ing techniques, as exemplified by Boliden. Successful gold
recovery requires understanding the ore’s mineralogy and
chemical-physical characteristics during treatment (Allan,
2001). Previous research demonstrated that mixtures
of collectors create a synergistic effect on froth flotation
(Lotter, 2010), motivating the evaluation of new mixtures,
especially for precious metals and complex ores. This arti-
cle presents advancements in metallurgical performance
for treating Åkulla’s Au-Tellurium mineralization from
Kankberg.
Boliden Area Concentrator
Currently there are four active underground mines in the
Boliden Area that supply ore to one mill. Ore is processed
in short campaigns lasting from a few days to several weeks.
There are several reasons for not blending the ores: they
have different hardness and grades, require different process
conditions, and produce concentrates with varying grades
and penalty elements. Additionally, avoiding ore blending
enhances metallurgical treatment for optimal performance
and facilitates metallurgical accounting. Most ores pro-
cessed are complex sulphide ores containing Cu-Pb-Zn,
along with Au and Ag, while Åkulla Kankberg ore has a
different mineralogy.
The Boliden Area concentrator processes about 1.6–
1.7 Mton ore annually depending on feed ore properties
and mines’ production. The plan consists of 3 independent
production lines, called A, B and C, where A is used exclu-
sively for processing of slag from nearby Rönnskär smelter,
Enhancing Gold-Tellurium Flotation Performance: A Study from
Laboratory to Industrial Scale on Åkulla Kankberg Ore at the
Boliden Plant
Carmel Vasconcelos, Anna Gulkova, Dominiqui Brising, Paulina Nordfeldt
Boliden Minerals
ABSTRACT: Au-Te mineralization is contained within quartz-andalusite and topaz alteration, with small
amounts of sulphide minerals. Gold is present in the ore as native gold and gold-tellurides. The flotation plant
aims to selectively float gold mineral particles to maximize production. This research presents the findings of
recovery and selectivity enhancements for gold, silver and tellurium at both laboratory and industrial scales by
substituting the main flotation collector. Quantification of the differences in metallurgical performance between
the collectors was evaluated, and quantified mineralogical characterization using QEMSCAN ® was done to
understand the process responses.
INTRODUCTION
Gold primarily occurs in its native form and secondarily as
gold in solid-solution, mainly in compounds with silver,
tellurium, and mercury (Zhang 2010). Au-Tellurium min-
eralization exhibits significant variation and can commonly
be classified into mineral member groups with silver, bis-
muth, and lead (Spory 2019). Generally, Au-tellurides are
processed with sulphide minerals, with recovery occurring
in the concentrate along with pyrite and other sulphides
(Yan, 1997).
The metallurgical process chain for complex miner-
als often involves flotation, leaching, and advanced smelt-
ing techniques, as exemplified by Boliden. Successful gold
recovery requires understanding the ore’s mineralogy and
chemical-physical characteristics during treatment (Allan,
2001). Previous research demonstrated that mixtures
of collectors create a synergistic effect on froth flotation
(Lotter, 2010), motivating the evaluation of new mixtures,
especially for precious metals and complex ores. This arti-
cle presents advancements in metallurgical performance
for treating Åkulla’s Au-Tellurium mineralization from
Kankberg.
Boliden Area Concentrator
Currently there are four active underground mines in the
Boliden Area that supply ore to one mill. Ore is processed
in short campaigns lasting from a few days to several weeks.
There are several reasons for not blending the ores: they
have different hardness and grades, require different process
conditions, and produce concentrates with varying grades
and penalty elements. Additionally, avoiding ore blending
enhances metallurgical treatment for optimal performance
and facilitates metallurgical accounting. Most ores pro-
cessed are complex sulphide ores containing Cu-Pb-Zn,
along with Au and Ag, while Åkulla Kankberg ore has a
different mineralogy.
The Boliden Area concentrator processes about 1.6–
1.7 Mton ore annually depending on feed ore properties
and mines’ production. The plan consists of 3 independent
production lines, called A, B and C, where A is used exclu-
sively for processing of slag from nearby Rönnskär smelter,