June 09, 2020 – Vancouver, British Columbia – VanGold Mining Corp (the “Company” or “VanGold”) (TSXV:VGLD) reports results from its 1,039 tonne bulk sample and metallurgical test of material from its El Pinguico silver and gold project, located 7km south of the city of Guanajuato, Mexico.
Bulk Sample and Metallurgical Test:
As reported in the Company’s June 2, 2020 news release, VanGold has completed its bulk sample and metallurgical test which consisted of delivering a total of 1039 wet tonnes of mineralized material from its El Pinguico silver and gold project for processing at Endeavour Silver Corp.’s (Endeavour) (TSX:EDR) nearby Bolanitos mill. Click here to see drone video footage of this work. The VanGold Story Episode 1: https://youtu.be/ZL13PWaexsg
Gold and Silver Recoveries:
The material used for this test came exclusively from the Company’s surface stockpile of waste material which was left behind when mining ceased at El Pinguico in 1913. The material has been exposed to the elements since that time and was therefore somewhat oxidized. Despite this, recoveries of gold and silver were very good, and may point to better recoveries in the future from less oxidized material located within the mine itself.
Average Recoveries:
Gold: 75.18% Silver: 60.36%
At times during the milling process the Company observed even higher gold and silver recoveries - up to 77.68% for gold and 67.19% for silver. The different grinding size and residency time within different circuits at the Bolanitos’ mill accounts for much of these differences. The entire process helped us gain a better understanding of how these higher recoveries were reached, and how they can be replicated in the future. The Company may also pursue additional lab tests in order to replicate the higher numbers and potentially apply that knowledge at one of the local Guanajuato mills.
Concentrate ratio 232 to 1:
The Company delivered 1039 wet tonnes to Endeavour Silver’s mill, which when dried became 1006 dry tonnes. With the help of VanGold’s consulting metallurgist, Mr. Augustin Parra, Professor of Metallurgy at the University of Guanajuato, the Company chose to use certain silica depressors as reagents in the milling process. This procedure created a very high concentrate ratio of 232:1 which is remarkable for the moderate grade material used in the test and may have the effect of dramatically lowering the cost of transporting potential additional concentrates in the future.
After separating and storing a small amount of the concentrate which the Company will have on hand to conduct future analytical tests, the final product consisted of 4.265 dry tonnes averaging 132.0 gpt Au and 6661 gpt Ag. Total recoveries from the final product credited to the Company by Endeavour were 18 ounces of gold and 913 ounces of silver.
Head Grade:
Vangold’s surface stockpile contains an exploration target of 175,000 to185,000 tonnes grading 1.25 to 1.35 gpt AuEq. These figures are conceptual in nature.1
The head grade in the 1039 tonnes of material sent to Endeavour Silver’s mill had an overall recalculated head grade, after processing, of 1.23 gpt AuEq (using a 96 to 1 gold to silver ratio). This is within the range of historically derived estimates, which gives the Company confidence that its calculations regarding the grade of its underground stockpile will be affirmed when it samples the bottom of the underground stockpile material.
This bulk sample was sent to Endeavour Silver’s Bolanitos mill, located to the north of Guanajuato and approximately 28 km from El Pinguico. Though sample material was derived exclusively from the Company’s surface stockpile, the Company anticipates that results from this test may have direct implications for the Company’s higher grade underground stockpile material, and for the project as a whole.
Next steps, as described in the Company’s news release dated June 2, 2020:
Clearing the Bottom of the El Pinguico Shaft:
With data from this bulk sample now in hand, plans are being finalized for crews to begin clearing the bottom of the El Pinguico shaft. In the 107 years since mining ceased at El Pinguico, approximately 30m of debris has accumulated at the bottom of this shaft. The Company plans to attach a hoist to its metal head-frame currently in place above the shaft and begin removing this material. Once this material has been removed, crews will be in a position to do three things:
1. Sampling the bottom of the underground stockpile: The underground (UG) stockpile consists of material that in 2012 the Mexican Geological Survey agency determined to be 174,500 tonnes in size.2 In 2017, VanGold conducted a trenching program at the top of the UG stockpile. This program resulted in a weighted average of all of the trench samples of 1.75 gpt Au and 183 gpt Ag.3 Once crews remove the material at the bottom
1 In 2012 a private company commissioned by the then owner of El Pinguico calculated the volume of the surface stockpile as 92,849.5 m3, with a surface of 15,769.40 m2. In January 2017, Findore S.A. DE C.V. (“Findore”), a private geological services company engaged by Vangold, dug 10 holes with a backhoe CAT machine in the stockpile at different locations and different depths, taking two samples from each hole (one at the top and one at bottom). The samples confirmed there was no movement of economic values from surface to bottom of the stockpile due to weathering and rains, with the average samples results as follows:
see & read more on
https://vangoldmining.com/wp-content/uploads/2020/06/VAN_NR_Jun.-09-2020-Results-of-Bulk-Sample.pdf |
