Goldsource Announces High Metallurgical Recoveries for Eagle Mountain

Vancouver, British Columbia--(Newsfile Corp. - September 13, 2018) - Goldsource Mines Inc. (TSXV: GXS) (OTCBB: GXSFF) (FSE: G5M) ("Goldsource" or the "Company") is pleased to report high metallurgical recoveries and positive grinding cost-benefit analysis at its 100%-owned Eagle Mountain Gold Project ("Eagle Mountain") in Guyana, South America. The metallurgical results show an average gold recovery of 96.7%, of which 24.4% of the recovery was from gravity tests and the remaining recovery was through cyanidation. The metallurgical testwork was conducted by SGS Canada Inc. at Lakefield, Ontario ("SGS Lakefield") under the supervision of Tetra Tech Inc. ("Tetra Tech"). The Company has retained the services of Tetra Tech, an independent Vancouver based company to complete a PreFeasibility Study ("PFS") for a potential large-scale open pit, gravity-cyanidation operation at Eagle Mountain.

Highlights of Metallurgical Study Results for PFS

• Average gold recovery of an estimated 96.7%, including an average recovery of 24.4% from the gravity tests with the remaining recovered through cyanidation.

• Conceptual grind size of an estimated 200 microns (P₈₀) through a standard gravity-CIP (carbon-in-pulp) plant.

• Approximately a minimum of 45% of mineralized saprolite is minus 200 microns and could bypass the grinding circuit with potential positive benefits in capital and operating costs.

• Low abrasiveness and standard work index in the saprolite mineralization.

• Leach residency times and reagents consumption within comparative standard industry levels.

• Positive cyanide detoxification results.

Yannis Tsitos, President, commented, "We are very pleased with the metallurgical results which are consistent with the preliminary gold recoveries announced on May 17, 2018. The overall gravity-cyanidation gold recovery remains at high levels (> 95%) even at coarser saprolite feeds in excess of 500 microns. Results indicate that a minimum of 45% of the total mineralized saprolite could bypass the grind circuit. Our efforts will continue at Eagle Mountain with focus on saprolite resources expansion, resource estimation and the conclusion of the PFS study."

Twenty-two saprolite samples representing the different mineralized zones of the Eagle Mountain deposits were collected (trench and core) with additional samples representing the existing pilot gravity plant tailings and the plus 2 millimetre ("mm") stockpile from the same operation. The bulk sample, totalling approximately 500 kilograms, was shipped to SGS Lakefield in Q1, 2018 for testing.

The test program consisted of grindability testing, sample characterization (assaying, sizing, mineralogy and gold deportment) followed by gravity separation and cyanidation. The received samples were grouped into seven composites designated as VC1 through VC7 for the purposes of the test program (see Table below). The Master Composite is a blend of the composite samples (VC1 to VC4 and VC7). The composite sample, VC5 is representative of the existing pilot gravity plant tailings from the 2016 operation. The composite sample, VC6 is representative of the plus 2 mm stockpile from the same pilot plant operation.

The results of the detailed metallurgical testwork are summarized as follows and in the table below: 

• The Bond Ball Mill Work Index is 16.3 kWh/t for the coarse fractions of the Master Composite (with no fines) and 8.1 kWh/t for the overall sample (including fines),

• The Bond Abrasion Index is 0.004, and indicates low abrasiveness in the mineralization,

• The gold grade for the Master Composite sample was 0.98 g/t.  The sulphur (as pyrite) content is <0.05%. No deleterious elements were noted in assays results,

• For the Master Composite sample, approximately 50% of the gold occurs within the finer fraction of minus 25 micron,

• The gravity concentration tests, excluding pilot plant tails, resulted in a gold recovery between 18.9 to 29.5% averaging 24.4%,

• Average cyanide leach test results from gravity tailings showed an average gold recovery of 96.7% which is in line with the results from the Master Composite sample,

• Test results show that the optimal grind size of an estimated 200 micron (P80) is required for the gravity followed by leaching, the applied standard condition for cyanide concentration was 0.5 g/L, and 

• The cyanide detoxification results indicated that the CN_WAD, present in the CIP barren pulp could be destroyed to levels below the typical effluent discharge requirement of 1 mg/L.

Summary of Gravity & Cyanide Leach Results

Notes:

* VC5 sample (Pilot Gravity Plant Tailings) without prior grinding or additional gravity separation; already passed through the FALCON Gravity Concentrators at the pilot plant.
** 48 hours leach residency times.

Summary of Gravity & Cyanide Leach Results from Coarser Grinding

Notes:

** 48 hours leach residency times.

The recommended proposed design rate for mineralized saprolite volume to bypass the grinding circuit for the PFS is 45%. No additional metallurgical testwork is recommended at this stage. However, further metallurgical testwork may be justified depending on the success of expansion drilling on newly defined targets.

Based on the above detailed metallurgical results, the general flowsheet for PFS conceptually suggests an open-pit mining operation followed by a standard gravity-grind-leach (CIP) processing facility at a throughput rate of 4,000 to 5,000 tpd.

The Qualified Persons under National Instrument 43-101 - Standards of Disclosure for Mineral Projects for this news release are N. Eric Fier, CPG, P.Eng, Chief Operating Officer and Executive Chairman for Goldsource, and Hassan Ghaffari, M.A.Sc., P.Eng, Director, Metallurgy Mining and Minerals, Tetra Tech Inc., who have reviewed and approved its contents.

ABOUT GOLDSOURCE MINES INC.

Goldsource Mines Inc. (www.goldsourcemines.com) is a Canadian resource company working aggressively to develop its advanced-stage, 100%-owned Eagle Mountain saprolite and hard-rock gold project in Guyana, South America. From 2016 to 2017, through a gravity pilot plant initiative, the Company completed testing on gravity-only gold production and both dry and wet mining open-pit techniques. Goldsource is now focused on delivering feasibility studies to achieve large-scale gold production at Eagle Mountain. Goldsource is led by an experienced management team, proven in making exploration discoveries and in project construction.

Ioannis (Yannis) Tsitos
President
Goldsource Mines Inc.

For Further Information:

Goldsource Mines Inc.
Contact: Ioannis (Yannis) Tsitos, President
Fred Cooper, Investor Relations
Telephone: +1 (604) 694-1760
Fax: +1 (604) 357-1313
Toll Free: 1-866-691-1760 (Canada & USA)
Email: info@goldsourcemines.com
Website: www.goldsourcemines.com
570 Granville Street, Suite 501
Vancouver, British Columbia V6C 3P1

CAUTIONARY STATEMENT AND FORWARD-LOOKING DISCLAIMER

This news release contains "forward-looking statements" within the meaning of Canadian securities legislation. Such forward‑looking statements concern Goldsource's strategic plans, timing and expectations for the Company's exploration and drilling programs at Eagle Mountain; metallurgical test estimates; and timing and completion of an updated resource estimate and a PFS. Such forward‑looking statements or information are based on a number of assumptions, which may prove to be incorrect. Assumptions have been made regarding, among other things: conditions in general economic and financial markets; accuracy of the interpretations and assumptions used in calculating inferred mineral resource estimates; availability of mining equipment; availability of skilled labour; timing and amount of capital expenditures; performance of available laboratory and other related services; and future operating costs. The actual results could differ materially from those anticipated in these forward‑looking statements as a result of the risk factors including: the timing and content of work programs; results of exploration activities and development of mineral properties; the interpretation of drilling results and other geological data; the uncertainties of resource estimations; receipt, maintenance and security of permits and mineral property titles; environmental and other regulatory risks; project costs overruns or unanticipated costs and expenses; and general market and industry conditions. Forward-looking statements are based on the expectations and opinions of the Company's management on the date the statements are made. The assumptions used in the preparation of such statements, although considered reasonable at the time of preparation, may prove to be imprecise and, as such, readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date the statements were made. The Company undertakes no obligation to update or revise any forward-looking statements included in this news release if these beliefs, estimates and opinions or other circumstances should change, except as otherwise required by applicable law.

Neither TSX-V nor its Regulation Services Provider (as that term is defined in policies of the TSX-V) accepts responsibility for the adequacy or accuracy of this release.