Source:
p. 6
Company | Interest | Ownership |
Galane Gold Ltd.
|
100 %
|
Indirect
|
Mupane Gold Mining Pty., Ltd.
|
100 %
|
Direct
|
Summary:
The Mupane Gold Deposit lies within the Tati Greenstone Belt (TGB) which comprises a NNW striking group of Archaean metavolcanic, metasedimentary and intrusive igneous rocks trending over 65km strike length and up to 20 km width.
The Mupane deposits are located in an area known as the Mupanipani Hills, ridges formed by outcrops of banded siliceous and graphitic iron formation (GIF). These units of so-called „iron formation? are hosted by a sequence of metasediments, including coarse grained carbonate bearing conglomerates, para amphibolites, marbles, metapelites and minor orthoamphibolites.
Tau was the largest gold deposit identified at Mupane. The reserves were depleted in 2009. It consists of two GIF-hosted lenses of gold mineralisation, termed the northern and the southern lenses which merge at between 80 m and 140 m depth to form a single ore lenses.
The deposit has an east-west strike length of 377m and has been defined to a maximum depth of 400 m. The ore zones vary in width between 3 m and 60 m and dips to the south at 45 o to 65o The Tau deposit is hosted within a quartz biotite/amphibolite-schist, minor garnet schists and a conglomerate unit. The western end of the mineralisation is truncated by a dolerite dyke, which is a part of the Karoo dyke swarm, and may be a remobilisation of the dyke along and pre-existing fault/shear. The grunerite associated with the amphibolite schist had weathered to form Nontronite clays in parts of the oxide/transitional zone.
The Tati Greenstone Belt (TGB) hosts numerous small scale nickel and gold deposits.
The nickel deposits consist almost entirely of disseminated to semi massive sulphide bodies hosted by a series of late stage troctolitic intrusive bodies on the northeastern edge of the greenstone belt.
The belt has been extensively prospected in the past due to the abundance of numerous small scale narrow quartz vein hosted gold deposits. These deposits are all clearly related to late stage, high level brittle shear zones developed within the volcanics and sediments of the belt.
The deposits were generally refractory in the fresh sulphides and contained significant amounts of arsenopyrite and some stibnite although the gold is principally hosted within pyrite and to a lesser extent pyrrhotite (i.e. Map-Nora Lodes). The alteration associated with the mineralisation varies depending on the host rocks but typically consists of biotite, muscovite, chlorite, carbonate and ubiquitous quartz either as veins or silicification. Very few of these deposits appear to have developed significant magnitude to be worthwhile propositions for modern gold mining.
In style the gold mineralisation conforms to the Archaean Lode Gold or Orogenic Gold style of mineralisation. They all appear to have formed late in the history of the belt and closely resemble mineralisation seen in the Archaean greenstone belts of Canada, South America and Australia.
Mineralisation is a “disseminated-style" in well-bedded, silicified quartz-rich parts of the graphitic iron formation (GIF) at Tau and Tholo and partly silicified graphitic schists at Kwena. This style of mineralisation is unlike that of most Achaean gold deposits being a broad siliceous zone. Mineralisation is not dominated by discrete veins and the deposit lacks sharply-bounded loads. The mineralized parts are however distinctive due to the silicification of the GIF.
The ore zone at Tau lies within the GIF unit. In comparison to unmineralized GIF, mineralized GIF is substantially altered. The addition of silica, remobilized silica, carbonate, wallrock fragmentation and the addition of vein quartz and sulphides have in large part overprinted the original features of the GIF. Mineralized GIF is highly siliceous and carbonated, highly deformed with the graphitic units strongly sheared. Deformation is ductile, with a very minor brittle component, mostly fracturing, and specifically fracturing of arsenopyrite. Minor vein quartz are brecciated, sheared and incorporate much of the GIF wallrock. Arsenopyrite is the most visual sulphide phase, and gold mineralisation is sulphidation of wallrock by this phase.
Mining Methods
- Truck & Shovel / Loader
- Blasthole slot
Summary:
Mupane gold mine has an underground and open pit mining plan currently focusing on its newly developed underground decline in the Tau orebody.
Mining activity is conventional open pit mining exploiting the Tau, Kwena and Tholo deposits in the immediate vicinity of the processing plant, and the remote Signal Hill, Molomolo and Golden Eagle gold deposits.
Delineation of the ore zones and associated grades is determined by grade control drilling using an RC rig. Where RC information is absent or widely spaced, blast-hole sampling is practiced. Assaying is done on the mine with results then being used to create the ore blocks.
Processing
- Gravity separation
- Flotation
- Concentrate leach
- Carbon in leach (CIL)
- Carbon adsorption-desorption-recovery (ADR)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Flow Sheet:
Summary:
The Mupane gold plant design was based on well understood and proven technology with the flow
sheet consisting of the following:
The flow sheet consists of:
-Crushing.
-Grinding.
-Flotation (for primary ore).
-Cyanide leach/carbon adsorption.
-Carbon desorption.
-Gold recovery.
-Cyanide detoxification and arsenic precipitation.
-Tailings disposal.
-Reagent mixing, storage and distribution.
-Water and power supply.
-Other services.
The flotation circuit operated during the period of February 2006 to February 2009 when sulphide ore was treated. However, carbon fouling was experienced and the subsequent unacceptable soluble losses led to its discontinuation. Since then process changes, such as grinding in cyanide, incorporating the regrind mill into the circuit and using the flotation cells as additional leaching reactors have been on trial and it is expected that this will negate the necessity to operate ........

Recoveries & Grades:
Commodity | Parameter | 2019 | 2018 | 2017 | 2016 | 2015 |
Gold
|
Recovery Rate, %
| ......  | ......  | ......  | ......  | ......  |
Gold
|
Head Grade, g/t
| 1.72 | 1.97 | 1.75 | 1.29 | 1.29 |
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Reserves at December 31, 2019:
Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
|
20 kt
|
Gold
|
0.98 g/t
|
0.6 koz
|
Probable
|
|
1,827 kt
|
Gold
|
1.97 g/t
|
115.5 koz
|
Proven & Probable
|
|
1,847 kt
|
Gold
|
1.96 g/t
|
116.1 koz
|
Measured
|
|
1,603 kt
|
Gold
|
1.42 g/t
|
73 koz
|
Measured
|
Tailings
|
12,851 kt
|
Gold
|
0.42 g/t
|
174.2 koz
|
Indicated
|
|
3,748 kt
|
Gold
|
1.43 g/t
|
172.6 koz
|
Measured & Indicated
|
|
5,352 kt
|
Gold
|
1.43 g/t
|
245.6 koz
|
Inferred
|
|
4,485 kt
|
Gold
|
1.4 g/t
|
201.9 koz
|
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