Company | Interest | Ownership |
Government of Mali
|
10 %
|
Indirect
|
Robex Resources Inc.
|
90 %
|
Indirect
|
Nampala SA.
|
100 %
|
Direct
|
Deposit Type
- Vein / narrow vein
- Orogenic
- Mesothermal
Summary:
Specifically, the Nampala deposit can be classified as a turbidite-hosted structurallycontrolled orogenic (mesothermal) lode-gold system.
Gold mineralization is primarily hosted in competent coarse-grained sedimentary rock where brittle fracturation, openings and veining occurred. Gold is associated to structurally controlled tension quartz vein systems and stockworks developed in the brittle fractures and in areas of increased porosity as a result of the deformation of the more competent coarse- grained greywacke, siliciceous sandstone and sandstone.
Shear zones are developed in the more ductile adjacent (or locally intercalated) shales (particularly the graphitic shale) and are commonly barren. Some narrow NNE-trending subvertical shear corridors are exposed in the pit from north to south and have been traced nearly continuously to the southernmost drill hole of the 2017-2018 drilling program.
Some anomalous gold values can also be found locally in the chill margins or along the contact of the intermediate intrusives. Local brittle deformation seems to have created space for tension quartz veins to penetrate the fringe of the stock and this seems to be confirmed by resistivity and conductivity geophysical maps which display what seem to be a slight NE/SW and NW/SE fracture pattern. This corresponds to the general orientation of the mineralization in the mine where mineralized domains are oriented 020°N and are controlled laterally by subvertical structures and stratigraphy. Within these delineations, as many as five generations of veins are observed and there seems to be a global plunge of 25-30° to the SW as well as the SE where flatter undulating quartz veins are noted. The mineralization type found at the Main and East zones is structurally controlled sediment-hosted orogenic gold affected by late intrusives. In both zones, the mineralized quartz veins have propagated into the more competent coarsegrained wakes, sandstones and arenites affected by brittle deformation. Through rheological contrasts between the different sediments, the plastic planar shear slipping along the ductile and less permeable siltstones and mudstones resulted in the propagation of interplanar shear bands, the brittle fracturing of arenitic rocks, the opening of tension jogs and the formation of dilation joints. As a result, quartz vein propagation and hydrothermal alteration of the protolith was favourable in the more porous sandstones and arenitic rocks. Hydrothermal alteration and quartz vein development patterns follow the structural corridors, filling extension gashes and jogs along shear corridors in the sediments and along the intrusives.
The dominant hydrothermal alteration in both zones is characterized by pervasive carbonatization-silicification and pyrite- arsenopyrite disseminations accompanied by chlorite and clay minerals (kaolinitization). The hydrothermal alteration displays outward zonation around quartz veins. The bulk of the sulphides occur as widespread disseminations of fine (submillimetre) pyrite and arsenopyrite. They are found within silicate-carbonate alteration rims in the wall rock around individual quartz veins, within quartz-carbonate veins. The degree of silicification and arsenopyrite concentrations appear to be slightly higher in the East Zone than in the Main Zone.
Summary:
The Nampala Mine is excavated using a conventional truck and shovel operation. The widest equipment used by the contractors is a Caterpillar 773B haul truck matched with a 385 hydraulic excavator. The ore and waste are composed mostly of saprolite located in the oxidized horizon. No drilling and blasting are required to access the current Mineral Reserve. A total of 7 pits are planned to recover the identified Mineral Reserve.
Processing
- Calcining
- Gravity separation
- Agitated tank (VAT) leaching
- Carbon in leach (CIL)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Flow Sheet:
Summary:
The proposed Nampala process plant design is based on conventional and wellknown CIL technology. The process plant will consist of scrubbing, crushing, milling, cyanidation by carbon in leach, Zadra elution method (used for recovery of gold from loaded carbon), electrowinning, carbon regeneration, calcining, smelting and tailing disposal. The plant comprises also reagent mixing, storage and distribution facilities, water, air supplies and infrastructures.
Recoveries & Grades:
Commodity | Parameter | 2019 | 2018 | 2017 | 2016 |
Gold
|
Recovery Rate, %
| ......  | ......  | 83.9 | 80.3 |
Gold
|
Head Grade, g/t
| ......  | ......  | 0.85 | 0.82 |
Production:
Commodity | Units | 2020 | 2019 | 2018 | 2017 | 2016 |
Gold
|
oz
| ...... ^ | ......  | 44,946 | 36,997 | 12,051 |
All production numbers are expressed as metal in doré.
^ Guidance / Forecast.
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Operational Metrics:
Metrics | 2019 | 2018 | 2017 | 2016 |
Ore tonnes mined
| ......  | ......  | 1,451,497 t | 680,621 t |
Waste
| ......  | ......  | 2,184,546 t | 1,613,814 t |
Stripping / waste ratio
| ......  | ......  | 1.5 | 2.4 |
Tonnes processed
| ......  | ......  | 1,615,966 t | 719,090 t |
Daily processing rate
| ......  | ......  | 4,400 t | |
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Reserves at August 1, 2019:
Category | Tonnage | Commodity | Grade | Contained Metal |
Probable
|
7,719 kt
|
Gold
|
0.73 g/t
|
180 koz
|
Indicated
|
16,304 kt
|
Gold
|
0.82 g/t
|
429 koz
|
Inferred
|
1,296 kt
|
Gold
|
0.74 g/t
|
31 koz
|
Total Resource
|
17,600 kt
|
Gold
|
0.81 g/t
|
460 koz
|
Commodity Production Costs:
| Commodity | Units | 2020 | 2019 | 2018 | 2017 |
Total cash costs (sold)
|
Gold
|
CAD
|
...... ^
|
......
|
643 / oz
|
618 / oz
|
All-in sustaining costs (sold)
|
Gold
|
CAD
|
...... ^
|
......
|
973 / oz
|
906 / oz
|
^ Guidance / Forecast.
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Operating Costs:
| Units | 2019 | 2018 | 2017 |
Total operating costs ($/t milled)
|
CAD
| 16 | 15 | 13 |
Financials:
| Units | 2019 | 2018 | 2017 |
Sustaining costs
|
M CAD
| ......  | 15.6 | 10 |
Revenue
|
M CAD
| ......  | 78.4 | 57.2 |
Operating Income
|
M CAD
| ......  | 25.5 | 22.6 |
Operating Cash Flow
|
M CAD
| ......  | 26.9 | 23.2 |
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Corporate Filings & Presentations:
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News:
News | Date |
Robex Resources Inc.: Acquisition of “Gladie” Permit and Beginning of Production for Four New Pits
|
March 30, 2021
|
Robex Resources Inc.: With 391,000 Ounces of Probable Mineral Reserves, Robex Expects a Mine Life of Nearly 9 Years for Nampala
|
October 25, 2020
|
Robex Resources Inc. Modifies the Released NI 43-101 Technical Report on August 9, 2019
|
June 5, 2020
|
Robex Resources Inc. Announces the First Encouraging Results of the 2020 Exploration Program.
|
May 22, 2020
|
Robex, Results Once Again Show Strong Improvement in 2019, With the Same Trend Continuing Into the First Quarter of 2020
|
April 28, 2020
|
Robex Resources Inc. Fourth Quarter 2019: New Production Progressing Very Well - Launch of an Ambitious Exploration Plan
|
February 6, 2020
|
Robex Resources: Nampala Project (Mali) - New Resource and Reserve Estimate
|
June 25, 2019
|
Aerial view:
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