Mine visit report: Silver Eagle (T.SEG)

 

I flew down to Mexico last week to visit the Miguel Auza project in Zacatecas. This is another of those old mining projects that has been brought back to life with the injection of capitol from a Canadian listed junior. The intriguing aspect of Miguel Auza is that the town of 14,000 people grew up around the old workings, and the mine is literally under the town. There are numerous old shafts and infrastructure right in the back yard of residential dwellings. Yet the town is supportive of the mine, and most of the employees live within walking distance of the office.

The project was assembled by gaining control of many small properties, and then additional staking enlarged the area to go pretty much from horizon to horizon. There are several productive veins that are very rich in silver with associated base metals, but past development only extended to very shallow depths because the vein structures act as a natural acquifer, and any extension of the workings below the water table resulted in heavy flooding beyond the capacity of pumping technology.

I witnessed this groundwater issue for myself at the lower levels of the workings, where drill holes driven into the vein behaved like pipes, allowing a strong flow of water to jet out. Mine workings typcially encounter water inflow, but to see water gushing out in such high volumes definately underscored the challenge to keep the workings dry enough to allow for mining activity. The company has high powered pumps working non-stop to divert the water out of the workings, and it is used for agriculture at the surface. There are no environmental concerns or toxins in this water.

The vein structures are typically narrow, ranging from a few inches to several feet across, but of very high grade. Mineralization is localized in steeply dipping quartz veins, bearing sulphides rich in silver minerals like galena. Wider zones of breccia surrounded many of the veins, with higher grade ore extending across a wider interval. Along the fault planes, rock had been ground down to a fine clay and enriched with leached silver that has assayed in the kilograms per tonne range. You could feel how heavy the clay was from these enriched layers.

I walked every inch of the developed workings along a decline ramp that has been driven to reach several of the veins outlined so far. Economic grade material has been excavated as they developed the workings and a stockpile of perhaps 5,000 tonnes is on surface awaiting the completion of the mill. The workings are very efficiently advanced with just enough room to allow for scoop trams and trucks to navigate carefully with minimal clearance.

The mill has been rebuilt and refurbished from the ground up, and it is the jewel of the operation. I noticed that every piece of equipment was in superb condition, custom rigged for a modern operation. A dedicated high voltage line separate from the town electrical grid is in place and brand new electrical equipment serves the mill.

The plant has been designed to allow for an increase in production as the scope of the mine grows. Proven and reliable equipment is in place, with no difficulty to source parts, bearings, and general maintenance. The crushing circuit is capable of 300 tpd at current capacity. Grinding is limited by the bottleneck of a ball mill rated to only 100 tpd, and to expand beyond that level will require a larger ball mill to be installed.

A standard floatation cell recovery method is in place, with 2 banks of cells dedicated for the production of a lead concentrate, and 2 for a zinc concentrate. Management hopes to achieve about an 80% overall recovery efficiency from the operation, after the standard learning curve for a new mill during which time they will tune the operation and experiment with different settings to generate the optimum results.

A tailings pond was under construction during my visit with an engineer right on site to ensure safety and durability. Since the pond is located along a slight rise, any failure of the dam would flood nearby agricultural land with tailings so care and attention during the construction process is of utmost importance. The pond design call for a secondary settling pond to be dug that will allow discharge water to be recycled and pumped back up to the mill. The capacity of this pond is for 90,000 cubic meters, enough to last for about 1 million tonnes of tailings, and nearly 10 years of production.

There is a possibility that the recovery operations may eventually expand to allow for a heap leach circuit, where old tailings plus the tailings from modern operations could be treated and recover additional silver, bringing the overall recovery efficiency above 90%. To do so would require an environmental permit application to handle cyanide, and this is an option that will be on the table in the years ahead. If silver breaks out to levels above $20, then it would become extremely attractive to process the tailings at low cost with such a method and generate additional strong revenues.

As it stands now, the mine is pretty much ready to go and production could commence as early as next month. They plan to run some lower grade material through the mill to test it out, and train mill staff. The mill is designed to run efficiently with 2 twelve hour shifts, employing just 6 people during the day when the crushing circuit is in operation, and 4 people on the night shift.

Other facilities were under construction during my visit, including a modern assay lab, a mechanical shop, as well as administration and service buildings.

The entire project has the look of a brand new, modern operation, and this stands in sharp contrast to many of the other older projects that I have been to see. The mine has tremendous potential for additional resources to be discovered and put into production, and the mill is going to operate at the highest of efficiency with the potential for additional capacity expansion during the life of the project.

Management strengths lie with the production side of the business, so I do not anticipate they will be unable to resolve the challenges that typically occur with a mine startup. The town and the State are fully supporting the project, and the company works with the attitude that everyone needs to be a beneficiary of their success for the company to move forward.

The company still has about $5 million in the treasury, and positive cash flow generation should commence shortly to help underwrite the aggressive development and exploration schedule. I am confident that they will be able to advance the project, yet will maintain a growth curve that does not over extend the financial resources. I am also encouraged that the company has a very quiet confidence in their objectives, and they specifically urged me to be conservative in my report and to allow them to deliver results without excess hype and promotion. What a refreshing change.

cheers!

COACH247