Orsu Metals Demonstrates up to 89% Recovery from Initial Metallurgical Tests on Primary Sulphide Material at the Klyuchi West zone, Sergeevskoe Gold Project, Russia
WHITEROCK, BC / ACCESSWIRE / December 18, 2018 / OrsuMetals Corporation (TSX-V: OSU) (“Orsu” or the “Company”) is pleased to announceadditional metallurgical test results on a primary sulfide sample (WK18-1) fromKlyuchi West prospect at the SergeevskoeGold Project in Russia. Positive cyanidation test results for oxide samplesfrom Adit 5 (85.17% to 95.3% recovery) and Kozie (91.72% to 92.32%) prospectswere announced on March 12, 2018. The 2018 drill holes and trenches were completedwithin a 1 sq km area in the southeast of the Sergeevskoe license at Zone 23,Adit 5, Klyuchi West and Kozie prospects, with scout holes drilled at theSergeeva and Peak Klyuchi prospects.
Highlights:Sample WK18, grading1.4 g/t Au, showed an 85.8% recovery of goldusing the gravity-flotation scheme with cyanidation. Atotal 89% of gold can be recovered after additional cyanidation of crushedgravity cakes.
Dr. Alexander Yakubchuk, Director ofExploration of Orsu commented: “Our first metallurgy tests for theprimary mineralization sample from the Klyuchi West prospect achieved 85.8% to89% recoveries of gold with cyanidation in gravity-flotation scheme. Thisresult is consistent with historically achieved recoveries at the nearbyKlyuchevskoe gold mine. Orsu is conducting additional metallurgy tests onsamples for the Zone 23 and Adit 5 prospects.”
Dr. Sergey VKurzin, Executive Chairman of Orsu commented: “Concurrently withestablishing a maiden resource at Sergeevskoe property, Orsu is conducting anextensive metallurgical testing program. The Company earlier reported excellentrecoveries from cyanidation tests for oxide samples from Adit 5 and Kozieprospects ranging between 85% to 95% recoveries (see press-release dated 12March 2018). We are now pleased to see the positive results of the initialmetallurgy test results on the sulphide mineralization from the mineralization ofthe Klyuchi West zones. We are encouraged by achieved gold recoveries, whichrepresent only initial standard tests, which have to be optimized further.”
The license of the Sergeevskoe Gold Project occurs immediately east fromthe Aleksandrovskoe open pit and gold plant owned by Zapadnaya Gold MiningLtd and to the west from the Klyuchevskoe gold license owned by Sun Gold Mining(Figure 1). The Klyuchevskoe (Klyuchi) gold deposit represents a +6 Moz goldendowment (see Orsu press-release dated September 21, 2016). Orsu owns a 90%interest in the Sergeevskoe Gold Project (see press release December 1, 2017).
As part of its 2018 exploration works, Orsu collected sampleWK18-1, consisting of visually unoxidized rock fragments, 100 mm in size andsmaller. The intrusive rocks contain chaotically-oriented veinlets involuminous gold-mineralized stockwork at the Klyuchi West prospect (see pressrelease August 8, 2018). Thetests included studies of chemical and physical properties, gravity andflotation beneficiation, as well as bottle roll cyanidation of gravity,flotation and gravity-flotation concentrates. The study was conducted at the IrgiredmetInstitute (“Irgiredmet”) in Irkutsk, Russia, which is specialized in conductingthe metallurgy tests and is independent from Orsu.
Figure 1. An outline of the 7.6 sqkm Sergeevskoe license area with location of principal gold prospects and two adjacentopen pits.
Sample WK18-1 (175.7 kg) was collected from drillcore of four holes, drilled atKlyuchi West (Fig. 1) as part of the 2018 exploration program. Mineralogical analysis identified that rocks consist of hydrothermally altered granite with numerous quartz-tourmalineveinlets with minor (0.8%) sulphides, mostly pyrite and rare chalcopyrite andarsenopyrite. Mineralogical analysis identified free gold (32%), with 95.9% ofgold in <0.1-millimetre (“mm”) fraction (Figure 2). Irgiredmet assayed 1.4 g/t Au, with 0.352%Stotal, 0.35% Ssulfidic, 0.42% Ctotal, 0.017%As, 0.0074% Sb and <1 g/t Ag, indicating absence of detrimental elements. The oxidation state of sample is 38%. Microanalysis ofgold grains revealed 87.6–93.7% Au and 7.3–12.4% Ag. Mineralogical analysis estimated 84.8%of gold in amenable to cyanidation form.
In sample WK18-1, Irgiredmetmeasured a specific gravity of 2.67 t/m3. The measured Bond index (ВWi) is 18.6 kWt*h/t.
Figure2. <0.1mm gold grain present with pyrite (FeS2), arsenopyrite (FeAsS), galena (PbS), with minor sulfosalt (Sb-Cu-Zn-(As)-(Fe)-S) in gravity concentrate (-1.6 + 0.1mm). Polyshed section in secondary electrons, Camebax SX-50, Irgiredmet.
Gravity andflotation tests
GRG-test of WK18-1 sample using Knelson KC-MD-3 concentrator recovered 52.9% of gold, with 1.06% yield of gravity concentrate grading 83.9 g/t Au. The flotation study of gravity tailings produced a 69.8% recovery of gold into a 16.1 g/t Au concentrate (3.1% yield) and 0.19g/t Au in tailings.
Flotationtests of WK18-1 sample were conducted on 95% grinding to -0.071 mm class, with 79.6% of gold recovered into flotationconcentrate (with 6.9% yield),grading 14.5 g/t Au. The 65% grindingto -0.071 mm class demonstrated a 78%of gold recovered into flotation concentrate (with 5.8% yield), grading 17.8 g/t Au. In both cases, the concentration of gold in flotationtailings is 0.24 g/t. This demonstrates that gold recovery is not criticallydependent on the quality of grinding.
Directcyanidation of WK18-1 sample demonstrated an 80% recovery of gold during 24 hours.
Cyanidation of the specially prepared gravity concentrate,grading 63 g/t Au, recovered 82.6 to 85.7% of gold during 24 hours. Additionalcyanidation of crushed gravity cakes resultув in a total of89% recovery of gold. Cyanidation of the 0.8 g/t Augravity tailings recovered 78.2% of gold, with 0.19 g/t Au remaining intailings.
Cyanidationof the specially prepared flotation concentrate, grading 18 g/t Au, recovered79.82 to 80.65% of gold during 24 hours, with 0.19 g/t Au reporting intoflotation tailings. The cyanidation of the tailings showed 66.7% recovery ofgold.
Thestudy by Irgiredmet showed that 85.8% of gold can be recovered using thegravity-flotation scheme with cyanidation.
This release and the technical datareported have been reviewed and approved by Alexander Yakubchuk, Director ofExploration of the Company, also a Qualified Person as defined in NI 43-101.
Neither the TSX Venture Exchange nor its Regulation Services Provider(as that term is defined in the policies of the TSX Venture Exchange) acceptsresponsibility for the adequacy or accuracy of this release.
This newsrelease contains forward-looking statements that are based on the Company’scurrent expectations and estimates. Forward-looking statements are frequentlycharacterized by words such as “plan”, “expect”,“project”, “intend”, “believe”, “anticipate”,“estimate”, “suggest”, “indicate” and othersimilar words or statements that certain events or conditions “may”or “will” occur. Such forward-looking statements involve known andunknown risks, uncertainties and other factors that could cause actual eventsor results to differ materially from estimated or anticipated events or resultsimplied or expressed in such forward-looking statements. There may be otherfactors that cause actions, events or results not to be as anticipated,estimated or intended. Any forward-looking statement speaks only as of the dateon which it is made and, except as may be required by applicable securitieslaws, the Company disclaims any intent or obligation to update anyforward-looking statement, whether as a result of new information, futureevents or results or otherwise. Forward-looking statements are not guaranteesof future performance and accordingly undue reliance should not be put on suchstatements due to the inherent uncertainty therein.
For further information, please contact:
AlexanderYakubchuk, Director of Exploration, Orsu Metals Corporation
Doris Meyer, Corporate Secretary, Orsu MetalsCorporation
Tel: +1-604-536-2711 ext 6
SOURCE: Orsu Metals Corporation