Nampala Project (Mali): New Resource and Reserve Estimate

QUÉBEC CITY, June 25, 2019 (GLOBE NEWSWIRE) — Robex Resources Inc. (“Robex” and/or the “Company”) (TSXV: RBX/FWB: RB4) is pleased to report to the market the integration of all its 2018-2019 drilling results in a new Mineral Resource estimate and a new Mineral Reserve estimate in accordance with National Instrument 43-101.


Main highlights:

  • Indicated Mineral Resources increase of 77% and totaling 429,000 ounces of gold (compared to 242,000 ounces of gold in 2018 MRE) (216,000 oz in oxide type (principally saprolite), 105,000 oz in transition zone and 107,000 oz in fresh rock (sulphides)), which corresponds to a total of 16,304,000 t at 0.82 g/t Au. This represents an increase of more than 60% in tonnes of resources available and 10.8% in the average grade.
  • Inferred Mineral Resources totaling 31,000 ounces of gold (3,000 oz in saprolite type (oxides), 14,000 oz in transition zone and 31,000 oz in fresh rock (sulphides)), which corresponds to a total of 1,296,000 t at 0.74 g/t Au; 
  • Positive impact 2018-2019 drilling overall positive impact on the project. Despite the amount of gold produced since the last 2018 MRE, the NAMPALA’s drilling campaign (27,000 meters) has allowed increasing resources significantly. Furthermore, the 25,000 meters drilled on MININKO’s permit totaled over 52,000 meters drilled during the 2018-2019 campaign, nearly three times the effort for the previous campaign.
  • Reserve update. Following the 2018-2019 campaign, we have established a new reserve estimate. It was decided to carry out additional metallurgical tests before eventually integrating reserves in transition zone and in fresh rock. As a result, we can now report 180,000 ounces of reserves as at April 30, 2019 only in oxide, or 7,719,000 t at a grade of 0.73 g/t with a stripping ratio of 2.76.
  • Denis Boivin (QP Geologist) and Mario Boissé (QP Mining Engineer) have also updated the NAMPALA model block. They also established the economic envelopes and pit designs based on resources and reserves, respectively. 


The Nampala 2019 MRE has been completed under the supervision and responsibility of Mr. Denis Boivin, P.Geo., B.Sc., (OGQ #816), independent and qualified person under National Instrument 43-101, and by Mario Boissé, Eng., (OIQ #130715), independent and qualified person under National Instrument 43-101. Denis Boivin’s mandate was to validate the 2018-2019 drilling, to make a new model block and complete a compliant mineral resource estimate using all recent and validated data from the 2018-2019 drilling, validated historical exploration data and exploitation data coming from the current mining operation at Nampala. Mario Boissé’s mandate was to complete the economic envelopes and establish a compliant mineral reserve estimate using all recent and validated data from the 2018-2019 drilling, validated historical exploration data and exploitation data coming from the current mining operation at Nampala. Denis Boivin and Mario Boissé consider the 2019 MRE to be reliable, thorough, based on quality data, reasonable hypotheses and parameters that conform to NI 43-101 and CIM Definition Standards.

Table 1. – Nampala (2019) Mineral Resource Estimate

Category Cut-Off
Au (g/t)
Weathering type Tonnage
Au (g/t)
Au (000 oz)
Indicated 0.38 Oxide 9,223 0.73 216
0.48 Transition 3,666 0.90 105
0.48 Fresh rock 3,416 0.98 107
Subtotal 16,304 0.82 429
Inferred 0.38 Oxide 693 0.64 14
0.48 Transition 103 0.86 3
0.48 Fresh rock 500 0.86 14
Subtotal 1,296 0.74 31
Total 17,600 0.81 460

Table 2. – Nampala (2019) Mineral Reserve Estimate

Weathering type Probable Mineral Reserves Non-Reserve Material (Au > 0.38 g/t) Waste Stripping
Au (g/t)
Au (g/t)
Au (000 oz)
Au (g/t)
Au (000 oz)
Oxide 0.38 7,719 0.73 180 335 0.61 7 18,503 2.76
Transition N/A       1,551 0.79 39 860
Fresh rock N/A       31 0.62 1 8
Total   7,719 0.73 180 1,916 0.75 46 19,371

Notes to accompany  tables:

  1. The independent and qualified person for the mineral resource estimate, as defined by NI 43-101, is Mr. Denis Boivin, B.Sc., P.Geo., (OGQ #816) and Mr. Mario Boissé mining Eng. (OIQ #130715), and the effective date of the estimate is April 30, 2019.
  2. These Mineral Resources are not Mineral Reserves as they do not have demonstrated economic viability. The Mineral Reserves were established on the current technical capacity of the NAMPALA plant.   Mario Boissé recommends further metallurgical  to analyze the economic potential of the resources used in transition zone and in fresh rock for the 2019 MRE.
  3. The Mineral Resources and Reserves estimate follows 2014 CIM definitions and guidelines.
  4. The Mineral Resources include Mineral Reserves.
  5. Results are presented in situ and undiluted for open pit scenario and considered to have reasonable prospects for economic extraction.
  6. Grade interpolation was performed on the Nampala operating permit from 1 m drilling composites using the grade of the material analyzed and stripped at 15 g/t Au. The grade model was interpolated following the RBF (Radial Basis Function) method of the Leapfrog Geo software version 4.5.0 and evaluated in a 20-degree model block (10 m x 15 m x 5 m). In situ densities were interpolated using respective oxidation levels, with on average: Saprolite (oxides) = 1.60; Transition = 2.18 and Fresh rock = 2.63 (g/cm3).
  7. Resources are contained in an economic envelope built with the Lerch-Grossman optimization tool found in MineMap’s IMS software. Cut-off levels are set at 0.38 g/t Au for oxides and 0.48 g/t for transition rock and fresh rock. Cut-off levels were calculated based on: gold price USD 1,250/oz, CAD:USD exchange rate of 1.33 and the following parameters:
    1. Oxide: Mining cost=USD 2.00/t; Processing cost (Plant)=USD 8.70/t; USD/t; G&A=USD 2.30/t
    2. Transition: Mining cost=USD 2.41/t; Processing cost (Leach)=USD 8.92/t; G&A=USD 2.30/t
    3. Fresh rock: Mining cost=USD 2.55/t; Processing cost (Leach)=USD 8.92/t; G&A=USD 2.30/t
  1. The slope of the economic envelope is set at 40 degrees for an elevation of more than 330 m and 45 degrees for lower elevations.
  2. Reserves are contained in an economic envelope similar to that recovery is set at 0% in transition rock and healthy rock; The DCP (Distance to closest point) must be less than 30m in order to be categorized in the indicated; Mining recovery is 97%. In addition, a mining design with 7 pits serves as a final constraint or:
    1. A 21m wide ramp at a 10% slope is established to the bottom of the pits.
    2. 10m benches with a 5m bench establish a wall angle at 46.2 degrees.
    3. Potential pits with a diameter of less than 100m are ignored.
  1. The number of metric tonnes was rounded to the nearest thousand and the metal content are presented in troy ounces (tonne x grade / 31.10348). Any gap between the totals is due to the rounding effects. The rounding practices are in accordance with the recommendations established by the appendix 43-101A1.
  2. Denis Boivin P.Geo and Mario Boissé Eng. are not aware of any known environmental, permitting, legal, title-related, taxation, socio-political or marketing issues, or any other relevant issue not reported in this Technical Report that could materially affect the mineral resource estimate.

Robex Resources estimates that, based on these assumptions, the current rate of production already suggests that beyond the 4 years of proven production (2023), ROBEX has ample time to invest in, we hope, abundant discoveries of new resources. In addition, the very large increase in resources gives hope that the metallurgical tests to be carried out will already transform some of the resources established into new reserves.


To follow up on the positive results from the 2018-2019 drilling, the 2019 MRE and recommendations, a 2019-2020 drilling program will focus on the areas (West, East and South) with the main objectives of confirming continuity and achieving a definition campaign allowing the eventual publication of new resources in oxide mainly. The new program plans an effort of approximately 30,000 meters of drilling comparatively to the 25,00 meters of the campaign that has just ended on NAMPALA. This campaign will take place after the rainy season. The Company will regularly communicate the results obtained (as one goes along).

For financial efficiency reasons, NAMPALA is building an in-house mining exploration and planning department with a new 700 m2 core sample room that complements the current core sample room, and a heavy training program for our internal employees.


The geological and technical information contained in this press release have been validated by Mr. Denis Boivin P.Geo., B.Sc., (OGQ #816) and Mr. Mario Boissé Eng. (OIQ #130715), qualified and independent people under NI 43-101. The Technical Report in accordance with NI 43-101, supporting results in this press release which will be entitled “NI 43-101 Technical Report and Mineral Resource and Reserves Estimate for the Nampala Gold Mine”, will be available incessantly and within the regulatory deadlines on SEDAR ( and on the Company web site (


“Robex Resources has established a rigorous development policy based on planned steps. After regenerating the fundamentals of the NAMPALA project, we then built a very effective production tool which is based on an operational plant. Next we brought a plant to very efficiently operations. We are now approaching the development and expansion phase of the project, according to the re-engineered knowledge of our mineralized assets through the 2018 43-101 and plan for the future with this new 2019 43-101 which demonstrates the very significant increase in our resources. We can now continue our development by maintaining our exploration effort, carrying out the metallurgical work to adapt our current plant and thus process many more different types of ore. This cautious and structured step-by-step policy allows us to quickly build a solid mining operation that we hope to increase steadily. At the same time, we are actively pursuing our deleveraging policy.”

For information:

Robex Resources Inc.
Benjamin Cohen, CEO
Augustin Rousselet, CFO/COO
Head office: 581-741-7421
[email protected]            

This press release contains statements that may constitute “forward-looking information” or “forward-looking statements” as set out within the context of security law. This forward-looking information is subject to many risks and uncertainties, some of which are beyond Robex’s control. The actual results or conclusions may differ considerably from those that have been set out, or intimated, in this forward-looking information. There are many factors that may cause such disparity, especially the instability of metal market prices, the results of fluctuations in foreign currency exchange rates or in interest rates, poorly estimated reserves, environmental risks (stricter regulations) , unforeseen geological situations, unfavourable extraction conditions, political risks brought on by mining in developing countries, regulatory and governmental policy changes (laws and policies), failure to obtain the requisite permits and approvals from government bodies, or any other risk relating to mining and development. There is no guarantee that the circumstances anticipated in this forward-looking information will occur, or if they do occur, how they will benefit Robex. The forward-looking information is based on the estimates and opinions of Robex’s management at the time of the publication of the information and Robex does not assume any obligation to make public updates or modifications to any of the forward-looking statements, whether as a result of new information, future events, or any other cause, except if it is required by securities laws. Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

Comments are closed.

Free newsletter for stock pics, interview transcripts & investing ideas