Silver Bull Updates Its NI43-101 Resource For The Sierra Mojada Project
VANCOUVER, BC - Silver Bull Resources, Inc. reported an updated NI43-101 Resource report for the Sierra Mojada Project in Coahuila, Mexico. Highlights include: A "Measured and Indicated" (M&I) Global resource of 58.7 million tonnes grading at 3.6% zinc and 50 g/t silver for 4.670 billion pounds of zinc and 90.8 million ounces of silver. An open pittable high grade "Zinc Zone" within the Global resource of 10.03 million tonnes at an average grade of 11% Zinc at a 6% cutoff for 2.426 billion pounds of zinc. An open pittable high grade "Silver zone" within the Global resource of 19 million tonnes at an average grade of 102.5 g/t at a 50g/t cutoff for 62.6 million ounces of silver.
An additional underground "Measured and Indicated" resource outside of the open pit resource of 1.9 million tonnes at an average grade of 9.4% Zinc at a 6% cutoff for 388.5 million pounds of zinc.
The global resource is an average of the zinc, silver, copper and lead mineralization across the entire ore body and is broken into two parts: 1) An open pittable resource that has been defined using a "Lerchs-Grossman" (LG) optimized pit and which represents 96% of the total deposit, and 2) An additional underground resource which represents mineralization that was not included in the open pit due to its depth, but may be economic if mined from underground.
In order to establish the economics in an open pit context, the reported resource falls within a LG Optimized pit shell that uses a zinc price of US$1.00/lb and a silver price of US$18/oz with a recovery of silver estimated at 75% and zinc at 41%. Pit walls are set at 55 degrees overall, mining costs were assumed to be US$1.50/tonne, and silver and zinc processing costs were assumed to be US$12.00/tonne, which results in a total NSR cutoff for the resource of $13.50/tonne. The underground zinc resource was estimated at a 6% cutoff.
Mineral resources were estimated by ordinary Kriging using GEMS™ modeling software in multiple passes using 10 meter X 10 meter X 10 meter blocks as the SMU size. The geologic wireframes were updated and a percentage model technique utilized to calculate accurate volumes. Grade estimates were based on 1 meter composited assay data with search radius restricted to a 20 meter search radius when a zone dependent cap limit was reached. Blocks have been classified as measured, indicated or inferred mineral resources.
The Global Resource encompasses two high grade zones of oxide mineralization; the zinc zone, and the silver zone and represents an overall average grade for the silver and zinc mineralization across the entire deposit. This average grade does not accurately reflect the discrete, high grade zoning of the silver and zinc mineralization that occurs within the resource. To better reflect high grade silver and zinc zones which form separate coherent bodies within the larger global resource we have broken out the zinc and silver mineralization using zinc and silver cutoff grades.
The Sierra Mojada project is one of only a handful with any appreciable zinc resources and is one of the largest undeveloped silver-zinc projects in Mexico. It has excellent infrastructure; it is located 3 hours from an international airport with a paved road right to site; it has a functioning railway right to site; runs on grid power; and it has a skilled mining work force to draw upon in the immediate local area. The resource provides exposure to both the precious and base metals markets and has the potential to be scaled in size depending on metal prices. In short, we believe there are not many projects like this in the world."