XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3605
stage are indicated, as these have been used in a high-level
financial analysis later in this paper.
STAGEWISE IMPLEMENTATION CASE
STUDY
The following case study presents the design for a proposed
stagewise implementation of GT technologies for an exist-
ing gold operation. The operation is based in Africa and
has approximately three (3) years of processing remaining
for the current oxide ore body. There are two neighbouring
sulfide deposits consisting of both pyrite and arsenopyrite-
hosted gold. The majority of non-sulfide gangue is present
as silicates and carbonates. The following subsections will
consider the project specific requirements for each stage,
accompanied by a detailed discounted cash flow financial
analysis of three (3) contrasting implementation scenarios:
whole-of-plant, stagewise and semi-stagewise.
Stage 1: Concentration (Jameson Concentrator)
The mineralogy and grades of the ore to be fed to the con-
centrator are summarised Table 1.
Flotation testwork yielded the following grade recov-
ery curves (Figure 5). It is noted that the grade-recovery
curves here related only to Jameson Cell testwork which
were completed after conventional flotation cell testwork.
Based on the results of the flotation work, a P80 of
150 µm was selected, with ore to be fed to a Jameson Cell
flotation circuit at a rate of one million tonnes per annum
(125 tph). The circuit required to treat this feed will consist
of one Jameson rougher cell and one Jameson scavenger cell.
Stage 1 will be characterised by the production of a
saleable concentrate (Point A on the grade recovery curve
in Figure 5), at a grade of 30 g/t gold for a recovery of
85% gold and a total mass pull of 6%. Due to the arsenic
content of the concentrate (7%), it has been assumed that a
penalty will apply to concentrate sales and a payable rate of
75% contained gold has been applied.
The sale of the concentrate after the commissioning
of the Jameson Concentrator circuit will bring additional
revenue forward whilst the remaining design, installation
Comminution
Fine Grinding
(IsaMill™)
Oxidative Leach
(OxiLeach™)
Flotation
(Jameson
Concentrator™)
Saleable
Concentrate
Cyanide Leach
(CIL) Plant
Dore Production
Tailings Storage
Ore Feed /
Tailings
Figure 4. Typical processing flowsheet for extending life of mine (LOM) of an existing operation and stages of implementation
Table 1. Ore grade to Jameson concentrator
Mineralogy
Pyrite %2.16
Arsenopyrite %1.82
Quartz %38.93
Muscovite %23.36
Chlorite %9.15
Dolomite %12.32
Grade
Au g/t 1.96
As %0.35
S %0.80
stage are indicated, as these have been used in a high-level
financial analysis later in this paper.
STAGEWISE IMPLEMENTATION CASE
STUDY
The following case study presents the design for a proposed
stagewise implementation of GT technologies for an exist-
ing gold operation. The operation is based in Africa and
has approximately three (3) years of processing remaining
for the current oxide ore body. There are two neighbouring
sulfide deposits consisting of both pyrite and arsenopyrite-
hosted gold. The majority of non-sulfide gangue is present
as silicates and carbonates. The following subsections will
consider the project specific requirements for each stage,
accompanied by a detailed discounted cash flow financial
analysis of three (3) contrasting implementation scenarios:
whole-of-plant, stagewise and semi-stagewise.
Stage 1: Concentration (Jameson Concentrator)
The mineralogy and grades of the ore to be fed to the con-
centrator are summarised Table 1.
Flotation testwork yielded the following grade recov-
ery curves (Figure 5). It is noted that the grade-recovery
curves here related only to Jameson Cell testwork which
were completed after conventional flotation cell testwork.
Based on the results of the flotation work, a P80 of
150 µm was selected, with ore to be fed to a Jameson Cell
flotation circuit at a rate of one million tonnes per annum
(125 tph). The circuit required to treat this feed will consist
of one Jameson rougher cell and one Jameson scavenger cell.
Stage 1 will be characterised by the production of a
saleable concentrate (Point A on the grade recovery curve
in Figure 5), at a grade of 30 g/t gold for a recovery of
85% gold and a total mass pull of 6%. Due to the arsenic
content of the concentrate (7%), it has been assumed that a
penalty will apply to concentrate sales and a payable rate of
75% contained gold has been applied.
The sale of the concentrate after the commissioning
of the Jameson Concentrator circuit will bring additional
revenue forward whilst the remaining design, installation
Comminution
Fine Grinding
(IsaMill™)
Oxidative Leach
(OxiLeach™)
Flotation
(Jameson
Concentrator™)
Saleable
Concentrate
Cyanide Leach
(CIL) Plant
Dore Production
Tailings Storage
Ore Feed /
Tailings
Figure 4. Typical processing flowsheet for extending life of mine (LOM) of an existing operation and stages of implementation
Table 1. Ore grade to Jameson concentrator
Mineralogy
Pyrite %2.16
Arsenopyrite %1.82
Quartz %38.93
Muscovite %23.36
Chlorite %9.15
Dolomite %12.32
Grade
Au g/t 1.96
As %0.35
S %0.80