PPX Mining Corp. has designed a test mining and bulk sampling program on the Callanquitas Structure at Igor that will generate real-life mining costs and evaluate different mining techniques for extracting Callanquitas gold and silver mineralization. The bulk sampling is intended to validate our resource model by mining large tonnage samples from specific areas within the block model to confirm the widths and grades shown in our resource estimate. Utilizing the block model from the Company’s previously published resource estimate and the diamond drill hole database, PPX Mining geologists have created a mine plan that selectively extracts carefully selected blocks from the resource model. These blocks were based on overall grade, relative content of gold and silver, relevance to the metallurgical testing program, and the degree to which the blocks represent the technical characteristics of the entire resource. The Company intends to use the data obtained during the test mining and bulk sampling program to complete a Canadian National Instrument 43-101 Pre-Feasibility Study (“PFS”) in 2018. The PFS will evaluate various development options and define project economics for the possible commercial development of an integrated mining and processing operation focused on the Callanquitas Structure.
To date (March 2018), the company has extracted over 12,000 tonnes of mineralized rock with an average grade of 8.30 gpt Au, in agreement with the grade indicated by our block model. In addition, the company has stockpiled approximately 5,400 tonnes of “low-grade” rock grading 5.0 gpt Au for processing at a future date. The test mining has demonstrated several important technical characteristics for future mining:
- Rock quality and stability has been good in both development headings (ramps) as well as in areas of bulk sampling. Ground support has consisted of split set bolts and wire mesh in areas adjacent to the Callanquitas structure, with additional timber support for workings in the mineralized structure (raises and bulk sampling areas).
- Mine geologists and engineers have been able to extract bulk samples from the Callanquitas structure in a straightforward manner with visual grade control. We are experimenting with different mining and stopping techniques to determine what stopping methods work best in terms of cost and minimizing mine dilution. Grade continuity, as demonstrated by channel sampling (shown below) and the bulk samples, is excellent.
- Direct mining unit costs to date have been acceptable. The company is continuing to work with our mining partners Proyectos La Patagonia (PLP) to determine the lowest cost development strategy for basic mine infrastructure (ramps and raises).
Mina Callanquitas is currently extracting mineralized rock at a rate of approximately 120 tonnes per day. The mine achieved a sampling rate of 150 tonnes per day during December, 2017 and portions of January 2018, validating stoping methods for potential future production.