Sirios obtains up to 97% gold recovery including 88% by gravity on the Cheechoo project

MONTREAL, QUEBEC – Management of SIRIOS (TSX-V:SOI) is pleased to announce the positive results of the Phase I metallurgical testing undertaken by COREM. Gold recovery rates up to 97% were obtained, including 88% by gravity as shown in the table below. The tests were conducted on three composite samples of PQ drill core, each of approximately 130 kg.

 

Gold recovery by gravity and tailing cyanidation

Sample #

Lithology Head grade

(Au g/t)

Gold Recovery (%)

Grade obtained (Au g/t)

Gravity

Tailing Cyanidation

Total

9 Tonalite 0.56 81.4 15.2 96.6

0.92

12 Pegmatite 3.06 88.0  9.1 97.1

2.81

26 Meta-greywacke 0.27 56.5 34.5 91.0

0.31

The tonalite, sample #9 represents approximately 70% of the gold mineralization on Cheechoo. Samples # 12 and 26 represent respectively approximately 20% and 5% of the gold mineralization.

The grades obtained from the metallurgical tests show a significant increase compared to the head grades for the low-grade samples #9 and #26, while a slight decrease is observed for the sample #12. A population of 3 samples is however, not sufficient to define a general trend, further studies of variations in gold grade will be conducted when Phase II of the metallurgical testing will be completed and available.

Dominique Doucet, President, stated: “We are very encouraged by the results of these metallurgical tests which show that the type of gold mineralization in Cheechoo is easy to extract and has high recovery rates.”

Gold recovery by gravity (GRG) tests undertaken in Phase I, were conducted following the standard procedure developed by the late André Laplante, PhD, involving three successive separation steps with re-grinding between each step.

The tests also demonstrated the potential to concentrate the sulfides in the tailings of the gravity process using flotation. Note that there is a very low sulfides content, in the order of less than 0.2%, in the tailings from the treatment of Cheechoo samples.

Cyanidation tests via direct feed, demonstrate a low consumption of reagents, in the range of 0.19 and 0.58 kg/t of NaCN, and 0.56 and 1.09 kg/t of Ca(OH)2.

The whole of each sample was used for the comminution tests. Approximately 30 kg was used for gravity-testing, while 70 kg was used for cyanidation recovery tests at different granulometries, as well as quantitative mineralogy and gold deportment studies. The completed tests allowed the company to determine the granulometry, being P80 75 μm, to be used for the treatment of the 30 additional composite samples that constitute Phase II of the work currently underway at COREM. All thirty-three samples have a total mass of 5.5 tonnes (ref. press release of November 5, 2018).

Jordi Turcotte, MSc., Geo., and Dominique Doucet, P. Eng., Qualified Persons pursuant to National Instrument 43-101, prepared and verified the technical information of this press release, as well as reviewed the final text.