Tocvan Ventures Corp C.TOC

Tocvan provides update on Gold/Silver heap leach study.

[lifegoeson]

It is already the end of August, vacations are ending as school starts again, brokers and traders will soon be back in full force trying to make money that they spent on vacations.

Tocvan closed Friday at $0.55 on 32,500 shares and traded another 220,000 for the week, a good consolidation of stock at these levels.

Tocvan released an important update on the 45 day heap leach study, quote....

"The report findings include a base of 62-per-cent recovery of gold and 47-per-cent recovery of silver. Head grade results were calculated by LTM (LTM is the consultant hired to conduct the study) as 1.9 grams per tonne (g/t) gold (Au) and seven g/t silver (Ag), with calculated recoverable metal extracted at 1.2 g/t Au and three g/t Ag." 

My first reaction was, why was the recovery so low? But it became clear that during the 45 day leach, the first 30 days were problematic, quote,

"The first 30 days of leaching were restricted by an erratic and low flow rate of cyanide leaching solution. This was corrected once identified through the installation of updated irrigation systems, and began instantly improving irrigation flow rate and metal recovery."

Further, the consulting company suggested better overall efficiency will be obtained once these problems are corrected, implying a much better extraction rate for gold, quote, "LTM notes that increased gold and silver recovery is likely with a more consistent flow rate. LTM has recommended a duplicate column leach study of available bulk sample composite material to verify the ultimate gold and silver extractions under heap leach. It is also important to note the low cyanide (NaCN) consumption recorded (0.19 kilogram per tonne (kg/t)), indicating low cost of operation."

Then an important agitated bottle roll test was completed for minus-20 mesh finer material that was not included in the heap leach study, that resulted in amazing results in a 24 hour period, quote,

"In addition to the heap leach study, an agitated bottle roll test was completed by LTM on a bulk sample composite for comparison of the two methods. Rapid gold and silver recovery was recorded from minus-20 mesh material returning 80-per-cent recovery of gold and 94-per-cent recovery of silver after just 24 hours of retention time. Follow-on agitated leach and gravity tests are recommended to further evaluate the ability to utilize rapid recovery methods in lieu of the slower heap leach method."

Highlights:

• Recovery results for heap leaching match regional operating mines -- head grade exceeds expectations:
  • 62-per-cent recovery of gold achieved over 46-day leaching period;
  • Report confirms with increase in irrigation flow rate, higher recovery can be achieved;
  • Head grade calculated at 1.9 g/t Au and seven g/t Ag, and extracted grade calculated at 1.2 g/t Au and three g/t Ag;
  • Bulk sample only included coarse fraction of material (plus-three-fourths-inch to plus-one-eighth-inch);
  • Fine fraction (minus-one-eighth-inch) indicates rapid recovery with agitated leach.
• Recap of fine fraction and gravity recovery results:
  • Agitated bottle roll test returned rapid and high recovery results:
    • 80-per-cent recovery of gold and 94-per-cent recovery of silver after rapid 24-hour retention time.
  • Gravity recovery with agitated leach results of five composite samples returned:
    • 95 per cent to 99-per-cent recovery of gold;
    • 73 per cent to 97-per-cent recovery of silver;
    • Includes the recovery of 99 per cent Au and 73 per cent Ag from drill core composite at 120 metres depth.

This discussion summary was provided by Brodie Sutherland... "The bulk sample process has been extremely important to the understanding of the surface expression of mineralization at Pilar, along with defining a path towards optimal gold and silver recovery," stated Brodie Sutherland, chief executive officer. "We are encouraged by the strong heap leach results for gold where the data suggests recovery can be improved through increased leaching solution flow rate over a consistent and longer leaching period. Perhaps the most encouraging development from the study is the characterization of exposed gold and silver amenable to rapid gravity and agitated leach recovery. A quicker turnaround for metal extraction at very high recovery rates adds a new positive factor to the development path of the relatively high-grade nature of Pilar. Having optionality to explore both methods as viable extraction techniques makes Pilar a unique and standout deposit for the region, and with the potential now to explore an even greater area around to add to the potential resource size makes us even more excited for the future of the project."

I believe Brodie has been methodically building a science path that will result in one of the best optimized and efficient extraction systems for gold and silver in the Sonora area. We are still early in the game, but the signs of progress are very encouraging.

Now that August is almost over, and the work world will be returning to normal, it will be exciting to get the drills turning at Pilar and Picacho. Also finalizing the new massive land purchase will put significant further potential for Tocvan at Pilar, making it one of the best consolidated land masses in this area.