|September 19, 2016|
Rosita Mining Santa Rita Project Returns Positive Metallurgical Results
|Rosita Mining Corporation (RST:TSX-V) ("Rosita" or the "Company") is pleased to announce further positive metallurgical tests for the Company's Santa Rita Project presently underway at SGS Lakefield in collaboration with D.E.N.M. Engineering Ltd. Conventional cyanidation testing resulted in a 91% gold recovery from the surface stockpile ore and a 80% gold recovery from the tailings.|
The metallurgical tests were conducted on mineralized material composited from the Company's previous surface sampling at Santa Rita for the stockpile and tailings material. The as-tested head grade of the composited stockpile sample was 0.48 g/t Au and 1.01% Cu.
The tailings sample that was tested assayed 0.79 g/t Au and 0.28 % Cu.
Metallurgical testing was conducted on minus ¼ inch material ground to 80% passing 73-78 microns, typical for modern grinding and leaching facilities, for a leaching period of 48 hours.
In both cases (stockpile and tailings), the high cyanide consumption of 8.82 kg/t and 4.46 kg/t respectively is due to the requirement to maximize the dissolution of soluble copper and improve the kinetics of the resultant gold leaching. In both cases 69 % of the cyanide consumption was due to copper complexing with the cyanide; it is expected that the both the cyanide and copper can be recovered using SART technology developed by SGS, as outlined below. Also, in both cases, the gold residual values averaged in the 0.1 g/t range.
A single leach test was also carried out on plus ¼ inch material to test heap leach amenability. A similar residual value was obtained with a 75% recovery. Further heap leach simulation tests will be carried out to confirm this.
John Cook, President and CEO, stated that "It is good to see an improvement in the earlier gold recovery results thus reinforcing the preliminary flow sheet that was reported in the May 31st 2016 press release".
Next Phase Test Work
The results of this continuing metallurgical test work following earlier results from Rosita and Alder Resources are very positive, and indicate that the stockpile and tailings mineralization responds well to conventional cyanidation at readily achievable grind sizes.
The resultant solutions from these tests will be used for further SART (Sulphidization, Acidification, Recycling, and Thickening) testing with a goal to recover cyanide that has been complexed with copper, to recover the copper as a separate product and to recycle the resultant cyanide solution into ongoing cyanidation leach testing. This work will be carried out at SGS Lakefield as per the previous positive SART work, as reported in the March 21st press release. The results from this phase of the program will be reported as once additional metallurgical testing results are finalized.
Once this test campaign is complete, the resultant data will be used as the base for a 43-101 Preliminary Economic Assessment report to be completed later this year.
About Rosita Mining Corporation
Rosita is a junior mining and exploration resource company focused on growing shareholder value through the development of near-term mining projects and advancing accretive exploration opportunities.
Rosita and Calibre hold a 65% and 35% interest respectively in the Rosita copper-gold- silver supergene/skarn/porphyry project in Nicaragua located 275 kilometres northeast of Managua.
David Salari, P. Eng., and John Cook, MIMMM, Qualified Persons, as defined by NI 43- 101, have read and approved the contents of this press release.
For additional information, please visit our website at www.rositaminingcorp.com.
For further information, contact:
John Cook, President and CEO
Telephone: +1 416 200 8073
Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.
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