Cobalt at Castle
In addition to the Castle Silver Mine profitably operated by Agnico Eagle until the late 1980’s, the company also has 100% ownership of the Beaver and Violet cobalt silver properties located near the historic Castle Mine property. Roughly 300,000 pounds of cobalt was mined from the Castle property over the years, see August 3rd 2015 Technical Report with the Beaver property having historical documented cobalt production of another 140,000 pounds. Although cobalt has been in the news in recent months, work related to cobalt on the CSR properties dates to 2011 when drill hole CA11-08 from the historic Castle Mine property returned 6,476 grams (188.8 ounces) of silver per tonne over 3.09 metres (10.138 feet) including 0.91% cobalt over 0.45 metres (1.48 feet) plus hole CA11-09 returned 1.44% cobalt over 0.12 metres (0.39 feet.)
In February 2013, metallurgical tests on samples from the Beaver property were released. The Company’s geological consultant hand cobbed 400 kilograms of cobalt-nickel sulfide material from the historic waste pile at Beaver. A 20-kilogram sample was used in a test program, with an average calculated assay of 7.98% cobalt, 3.98% nickel and 1,246 g/t silver. Combined gravity-flotation recoveries from the limited test program yielded 64.2% for cobalt, 61.2% for nickel and 92.0%for silver.
Results from bench-scale metallurgical flotation and gravity test work press released January 31, 2017 showed silver and cobalt recoveries of 98.5% and 70.5% respectively with an extremely high concentrate grade of 11,876 grams per tonne silver and 10.5% cobalt produced using a simple flotation process. The mineralized-material surface rock sample was a composite collected from the waste pile assaying 2,064 grams per tonne silver and 5.62% cobalt at the Beaver Mine. Read the entire press release here Castle metallurgy results news release revised January 31 2017
In June 2017 CSR announced that chip sampling from the back of a quartz-carbonate vein on the first level adit at the Castle Silver Mine site confirmed the presence of high-grade cobalt. Highlights of the first five chip sample results were all strongly mineralized as follows: 1.8% cobalt, 8.6% nickel and 25.2 g/t silver (CSR-17-S03) plus 1.6% cobalt, 7.6% nickel and 32 g/t silver (CSR-17-S04) and 0.81% cobalt, 5.9% nickel and 4.1 g/t silver (CSR-17-S01)
Then in July 2017 in a demonstration of CSR’s underground advantage, an 82‐kilogram sample of vein material from the first level of the Castle mine at Gowganda was crushed to ‐10 mesh, blended and assayed, returning 1.48% cobalt, 5.7 g/t gold and 46.3 g/t silver. On July 19th, it was announced that SGS Lakefield had produced a 14.8% cobalt concentrate from recently sampled material from the first level of the Castle mine. The cobalt concentrate is now to go through CSR’s proprietary Re-2OX process with the goal of meeting the cobalt hydroxide specifications of four large Japanese metal trading companies that CSR management met with in Japan earlier in 2017.
On November 13, 2017 the results from an exploratory surface drill program within 200 meters of the adit at the Castle Silver mine were released with mineralization intersected in every hole highlighted by 1.55% cobalt, 0.65% nickel, 0.61 g/t Au and 8.8 g/t Ag over 0.65 meters at a very shallow depth (3.85 meters to 4.50 meters) in hole CA-17-16. It has been asserted and again evidenced that historical operators overlooked the potential for cobalt, gold and base metals at Castle preferring only to focus on the extraction of high-grade silver.
On December 1, 2017 it was press released that ongoing underground sampling had returned high-grade cobalt from additional areas on the first level of the Castle mine adit with highlights including, 3.1% cobalt in sample CSR-UG-T-2, 1.04% cobalt in sample CSR-UG-T-3, and 2.3% cobalt in sample CSR-17-10.
These bulk samples were obtained by removing muck rock from the floor of the drift and chipping out vein material over 2 lengths of 10 metres, each filling a 23-litre container with approximately 20 kg of material. A single composite sample was taken by randomly selecting approximately 2 kilograms.
On December 8, 2017 results from the Beaver Property were released also showing high-grade cobalt from three composite samples collected from select hand cobbed material at surface. The averages came in at 4.68% cobalt, 46.9 g/t silver and 3.09% nickel from the 38.7 kg samples combined weight.
Some of the next steps include trenching at the Beaver property and trenching at Castle to follow up on an array of new near-surface targets as identified by the 2017 drill program adjacent to the Castle mine adit. Additional trenching and drilling of untested structures on the first level of the mine adit is also planned which can be carried out through the winter season.