Overview

The Tucano Mine is located in Amapá State, Brazil, approximately 200 km from Macapá, the state capital, and is accessible via the Brazilian federal highway BR-210.

The Tucano Mine tenement portfolio is comprised of 197,283 ha, 100% controlled by Great Panther. This large land package in one of the most interesting areas in the world for gold exploration covers approximately a 90-kilometre-long section of the Vila Nova Greenstone Belt, centered around the Tucano Mining License.

The mine site is relatively remote but counts with existing infrastructure such as road access, hydro power, telecommunications and the port at Santana. The towns of Serra do Navio and Pedra Branca do Amapari are the nearby communities where 90% of the workforce comes from. The Santana port can accommodate relatively large ships as it was built for bulk material handling and has been in use until recently to handle iron ore from the Zamin property, adjacent to the Tucano Gold Mine site, to the southeast.

The Tucano Gold Mine is a well-established mining operation comprising eight open pits, the Urucum North underground project, a processing plant and tailings dam. Mine production to date has been sourced from all pits except Urucum East.

Mine production within the presently developed LOM pits is the responsibility of a mining contractor, U&M Mineração e Construção S.A. (“U&M”), and utilizes conventional earthmoving equipment with drill and blast, load and haul operations. The mined ore is blasted in eight-metre benches and dug in two four-metre cuts with backhoe excavators loading ore and waste into off-highway dump trucks. Mined ore is either fed directly to the crusher or temporarily stockpiled.

The existing processing plant was designed by Ausenco. After approximately four years of operation, an expansion was planned, also by Ausenco, as part of the original Definitive Feasibility Study to install a 3 MW ball mill. This new secondary grinding mill, alongside the 7 MW single stage SAG mill, was installed in order to maintain 3.1 million tonnes per annum throughput capacity treating 100% of the much harder sulphide ore type.

A new oxygen plant was installed at site in 2019 to deal with sulfide material and through that additional step recoveries of sulfide ores can reach higher than 90% recoveries.

Operating Results

 

Q4 2021

Q4 2020

Change

FY 2021

FY 2020

Change

Total material mined (tonnes)

6,260,316

6,605,369

-5%

23,455,626

25,483,176

-8%

Total waste mined (tonnes)

5,469,661

5,803,286

-6%

20,978,703

23,562,964

-11%

Ore mined (tonnes)

303,845

749,510

-59%

1,064,453

1,858,037

-43%

Ore processed (tonnes milled)

883,222

901,854

-2%

3,439,053

3,359,041

2%

Au grade (g/t)

0.77

1.23

-37%

0.78

1.28

-39%

Au recovery (%)

88%

90%

-2%

89%

91%

-3%

Gold production (oz)

19,107

32,017

-40%

75,919

125,417

-39%

Carbon fines gold recovery

223

100%

3,429

100%

Total gold production (oz)

19,330

32,017

-40%

79,348

125,417

-37%

Exploration

Tucano is hosted by the Proterozoic aged Vila Nova Greenstone Belt, the southern-most extension of the Guiana Shield, with many similarities to the greenstones in West Africa that contain many world-class deposits and to which the Guiana Shield was once connected. Tucano belongs to the sub-category of Iron Formation Hosted Gold Deposits, which includes notable names such as the historic Homestake Mine in South Dakota and the Musselwhite Mine in northern Ontario.

Tucano’s exploration package comprises 39 tenements covering an area of 1,972 square kilometres. These tenements are at various stages of advancement from application for exploration license to exploration license, and applications for mining licenses, through to mining concessions. There is a pipeline of high potential near-mine prospects, anchored by several high-grade gold drill intervals over several metres, which will be fast-tracked as near-term opportunities to increase resources and prolong the mine life. In 2020, Great Panther undertook a detailed evaluation of the available regional geophysical and geochemical data and developed a litho-structural model allowing the definition of high potential exploration corridors and targets within the large exploration tenement portfolio. In 2021 Great Panther initiated efficient regional exploration programs over these high potential corridors and is fast-tracking exploration of prioritized targets.

Highlights of resource conversion in 2020 drilling, in particular at Tapereba (“TAP AB”) on the southern part of the mine sequence, were reported on June 23, 2020, and a new Mineral Resource and Mineral Reserve estimate, on December 15, 2020. Highlight intercepts from TAP AB are presented below. These results demonstrate the presence of higher-grade mineralization within the mine sequence and the need to understand the controls on, and the grade and continuity variations, in these zones. In 2021, drilling focused on resource replacement and expansion for the open pit operations and deeper drilling to delineate and test variability and continuity of high-grade zones for inclusion in underground mining studies.

TAP C is a series of three pits over a 1,500 m trend of which the C1 pit is the largest with a depth of 50 m and a strike length of approximately 700 m. Initial results of drilling reported on April 7, 2021, and re-modelling of the TAP C1 deposit define the structural framework that has affected the mineralization. The updated model being used to guide ongoing drilling, explains mineralization discontinuities while providing better controls on areas of pinch and swell of the mineralized zones. The pit was mined by the previous operator down to the base of the oxide zone. The Tucano plant now has the capability to process both oxide and sulphide ore.

Exploration in the tenement package, which is around 90-kilometres-long by an average of 20-kilometres wide, includes over 500 kilometres of regional multi-element soil sampling complimented by auger and rotary air blast drilling. Once environmental permitting is in place, targets will be tested by Reverse Circulation drilling. 2021 initiated with activities on the Mutum and Saraminda targets that are being evaluated for fast-tracking.

Highlights from near-mine drilling at the TAP AB1 and AB3 open pits

Drill hole Interval (m) From (m) To (m) Est. true width (m) Grade (g/t Au)
DD020 10.25 231.95 242.20 7.3 6.55
including 1.05 234.60 235.65 0.7 29.29
DD020 1.95 247.05 249.00 1.4 26.95
DD018 29.40 161.60 191.00 13.5 15.99
including 6.40 161.60 168.00 2.9 38.33
including 2.40 172.60 175.00  1.1 16.20
including 4.00 177.00 181.00 1.8 27.99
DD016 20.20 167.00 187.20 11.9 1.89
DD012 6.25 4.20 10.45 4.5 6.21
including 1.59 5.41 7.00 1.1 17.37
DD009 16.70 188.00 204.70 10 10.96
DD007 20.00 201.00 221.00 14.3 1.71
DD003 3.00 22.00 25.00 1.4 31.70
RC003 12.00 47.00 59.00 5.7 8.06
including 1.00 51.00 52.00 0,5 64.89
RC004 22.00 84.00 106.00 7.3 4.78
  • DD = diamond drilling; RC = reverse circulation
  • Highlight drill results are +25 gram*metre intervals intersected in drilling this year.

2020 drill results from Tucano

Reserve & Resource Estimates

Mineralization at Tucano is controlled by a major north-south shear zone. The texture and mineralogy along the shear zone indicate high-temperature hydrothermal alteration. This zone exhibits intense hydrothermal alteration, particularly silicification and sulfidation, bearing auriferous pyrrhotite and pyrite. The alteration is most intense in the proximity of reactive meta-sediments such as banded iron formations and carbonate and, to a lesser extent, in calcsilicates, schists, and amphibolites. Late cross cutting intrusions are typically barren.

The mineralization at Tucano occurs in a series of deposits over a 7 km strike length associated with the north-south trending shear zone occurring coincident with a north-south line of topographic ridges. From south to north, these deposits have been named TAP AB, TAP C and Urucum.  Duckhead is a high-grade open pit to the southeast of the TAP deposits. Higher grades are associated with the more intensely hydrothermally altered rocks.

TUCANO MINERAL RESERVE ESTIMATES AT JULY 31, 2021

  Tonnes (000s) Grade Au g/t Contained Au oz
Open pit      
Proven 2,495 1.40 112,000
Probable

7,437

1.08 259,000
Total P&P

9,932

1.16 372,000
Underground      
Proven 189 3.78 23,000
Probable 1,976 4.17 265,000
Total P&P 2,164 4.13 288,000
Stockpile      
Proven 1,400 0.50 22,000
Probable 0 0 0
Total P&P 1,400 0.50 22,000
Total      
Proven

4,084

1.20 158,000
Probable

9,413

1.73 524,000
Total P&P 13,496 1.57 682,000

Notes:

  1. Mineral Reserves were classified using CIM Definition Standards (2014).
  2. Open pit Mineral Reserves are estimated within designed pits above marginal cut-off grades that vary from 0.40 g/t Au to 0.45 g/t Au for oxide ore and 0.46 g/t Au to 0.50 g/t Au for sulphide ore.
  3. Underground Mineral Reserves were estimated using a cut-off grade of 2.4 g/t Au.
  4. Mineral Reserves are estimated using an average long-term gold price of US$1,650/oz and a BRL:USD exchange rate of R$5.00:US$1.00.
  5. Mineral Reserves incorporate estimates of dilution and mineral losses.
  6. A minimum mining width of 15 m was used for open pit Mineral Reserves and 3 m was used for underground Mineral Reserves.
  7. Average metallurgical process recovery: 91.5%.
  8. Numbers may not add due to rounding.

TUCANO MINERAL RESOURCE ESTIMATES AT JULY 31, 2021

  Tonnes (000s) Grade Au g/t Contained Au oz
Open pit      
Measured

5,651

1.20 217,000
Indicated

18,863

1.17 711,000
Total M&I

24,514

1.18 928,000
Inferred

1,476

1.10 52,000
Underground      
Measured 0 0 0
Indicated

2,493

4.41 353,000
Total M&I 2,493 4.41 353,000
Inferred 5,306 2.73 466,000
Stockpile      
Measured 1,400 0.50 22,000
Indicated 0 0 0
Total M&I 1,400 0.50 22,000
Inferred 0 0 0
Total      
Measured 7,051 1.06 240,000
Indicated 21,355 1.55 1,064,000
Total M&I 28,407 1.43 1,303,000
Inferred 6,782 2.37 518,000

Notes:

  1. Mineral Resources were classified using CIM Definition Standards (2014).
  2. Mineral Resources are inclusive of Mineral Reserves.
  3. Since the prior MRMR estimates, drilling results are available for the TAP AB, TAP C, and Urucum open pit resources.
  4. Mineral Resources are estimated at various cut-off grades depending on mining method, mineralization style and haulage distances.
  5. Mineralization wireframes were generated at 0.3 g/t Au for open pit resources except for URCN where a 0.5 g/t Au wireframe was used. Underground resources were calculated within a 1.6 g/t Au wireframe. The minimum wireframe width is three metres.
  6. Mineral Resources are estimated using a long-term gold price of US$1900/oz and a US$:BR$ exchange rate of 1:5.
  7. The Company's Mineral Resource estimates were prepared by Mr. Carlos Henrique Pires, F. AusIMM, a full-time Tucano employee and a Qualified Persons as defined by NI 43-101.
  8. Numbers may not add due to rounding.
  9. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. Mineral resources are subject to infill drilling, permitting, mine planning, mining dilution and recovery losses, among other things, to be converted into mineral reserves. Due to the uncertainty associated with inferred mineral resources, it cannot be assumed that all or any part of an inferred mineral resource will ever be upgraded to indicated or measured mineral resources, including, as a result of continued exploration.

QUALIFIED PERSONS

Great Panther's own technical Qualified Persons oversaw the process and carried out new estimates on the Urucum, TAP C and TAP AB open pit deposits.

On behalf of Great Panther, Fernando A. Cornejo, Professional Engineer, supervised the preparation of and approved for inclusion in this news release the Tucano Mineral Reserve estimates and Nicholas Winer, Fellow AusIMM, and Carlos Pires, Chartered Professional, Fellow AusIMM (CP), supervised the preparation of and approved for inclusion in this news release the Tucano Mineral Resource estimates Messrs. Cornejo, Winer and Pires are non-independent Qualified Persons as defined by NI 43-101.

The Qualified Persons for Mineral Resource estimation have reviewed the Tucano QA/QC program. The QA/QC program for drill core includes the regular insertion of blanks, standards and duplicates into sample batches, diligent monitoring of assay results, and necessary remedial actions. Resource drilling samples are first assayed at the Tucano onsite laboratory. All intervals with anomalous gold are submitted and re-analyzed by the Certified, SGS Geosol laboratory in Belo Horizonte by 50 g fire-assay. All SGS Geosol assays, after diligent monitoring of QA/QC and necessary remedial actions, supersede the Tucano assay results in the database for MRMR grade estimation. QA/QC monitoring of the SGS laboratory also includes inter-laboratory checks on five percent of samples with the Certified, ALS laboratory in Belo Horizonte. In addition to the data verification methodology described above, personal inspections of the Tucano property have also been completed.

Unless stated otherwise, all scientific and technical information contained in this news release has been reviewed and approved by Fernando A. Cornejo, P. Eng., Chief Operating Officer, and Nicholas Winer, Vice-President, Exploration of Great Panther, each a Qualified Person as defined by NI 43-101.

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NI 43-101 Technical Report on the Tucano Gold Mine

Amapa, Brazil   |   September 30, 2020

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