January 06, 2022, Vancouver, British Columbia. Blackrock Silver Corp. (the “Company”) is pleased to announce the results of its initial metallurgical test work on the Tonopah West high-grade, epithermal silver-gold vein system located along the prolific Walker Lane trend of Western Nevada. Results show that the silver-gold mineralization at the project appears to be amenable to standard cyanidation processing with average recoveries of 95% gold and 87% silver.
HIGHLIGHTS:
Twelve composites from 6 of the veins on the Tonopah West project returned an average gold recovery of 95% and an average silver recovery of 87%;
Gold recoveries range between 90% to 98%, and the silver recoveries range between 81% and 94%;
The Merten vein, the largest vein in the DPB resource area, returned an average gold recovery of 96% and a silver recovery of 90%;
The high-grade Bermuda vein yielded average recoveries of 93.5% for gold and 91% for silver; and
The DPB maiden resource is on track for Q1 2022.
Andrew Pollard, the Company’s President and CEO, stated, “Initial metallurgical testwork at the project has yielded very high silver and goldrecoveries that appear amenable to cyanidation, providing highly positive implications for the future development potential of the project. Historically, the Tonopah Extension Mining Company had a 60-stamp mill, which gave us a good indication that the metallurgy would be amenable to standard processing methods. This indication has now been confirmed with testwork showing excellent metal recoveries, representing a significant milestone in our crusade to quickly advance and de-risk the project. The two largest, and most important structures for us within the DPB resource area, the Merten and Bermuda veins, also returned the highest metallurgical recoveries. The results will support and inform our maiden resource estimate on our DPB vein corridor, anticipated for Q1, 2022.”
A total of twelve vein composites were assembled and delivered to Kappes and Cassidy (KCA) in Reno, Nevada. KCA completed cyanide bottle roll leach tests to test the initial metallurgical characteristics of the Tonopah West high-grade, epithermal silver-gold vein system. A low- and high-grade composite was created for each of the Victor, Denver, Paymaster, Bermuda, Merten and Mule veins. The metallurgical test returned average recoveries 95% for gold, and 87% for silver. The gold recoveries rangebetween 90% to 98%, and the silver recoveries range between 81% and 94%. These test results compare favorably to the historic recoveries achieved in the Tonopah district when gold and silver were liberated using stamp mills.
Blackrock project geologists constructed a set of low-grade and high-grade composites for each of the major veins in the DPB and Victors areas. The low-grade (LG) composite was assembled from coarse drill reject material based on gold and silver assays with a calculated silver equivalent (AgEq) grade of greater than 150 g/t AgEq, but less than 300 g/t AgEq. The high-grade (HG) composite was created of similar coarse reject material based on gold and silver assays with a calculated silver equivalent (AgEq) grade of greater than 300 g/t AgEq. The silver equivalent grade was calculated by using the silver assay added to the gold assay times 100. Table 1 shows the recoveries and associated parameters for the gold in each composite. Table 2 shows the corresponding silver recovery for each composite and the associated parameters of the bottle roll leach test. An average of the HG and LG recoveries is calculated in the last column of each table.
Table 1: Bottle Roll Leach Tests for Gold in Tonopah West Composites
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