New Opportunity At Zonia Copper Project
VANCOUVER - World Copper Ltd. provided an update on its Zonia copper-oxide project in Arizona. A review of historical data by World Copper's newly formed Technical Advisory Committee has revealed the potential for re-processing mineralized material that was included in the historical mine plan at the Zonia Project. This material, located on heap leach pads from historical production on private patented land, and last processed in the mid-1970s, was treated with acid to recover soluble copper. Two historical reports, a 1979 mine production summary report by McAlester Fuel Company and a 1982 resource evaluation report by Mountain States Research & Development (MSRD), indicate that the site hosts over 14 million tons of historically mined material available for re-processing: 7.1 million tons of run-of-mine mineralized material placed on three historical heap leach pads; and 7.7 million tons of blasted and leveled in-situ leach (ISL) mineralized material.
For the material placed on the three heap-leach pads, the average original (pre-leaching) copper grade estimated by drilling prior to production was reported to be between 0.6% total copper (CuT) (McAlester production report) and 0.4% CuT (MSRD report estimate based on drilling of the leach pads). This yielded 30.5 million pounds of copper during its operational period of March 1966 to March 1975, which means that between 26.7 and 55.1 million pounds of copper could remain unrecovered from the pads, based on the reported original grade of the mineralized material. McAlester further reported that between mid-1972 to March 1975, the ISL area produced 2.70 million pounds of copper from material with estimated original copper grades between 0.269% and 0.292% CuT (McAlester and MSRD respective estimates), indicating that this area could contain between 38.6 and 41.8 million pounds of copper. According to these two reports the total potential unrecovered material from both the three leach pads and the ISL area could range between 65 million pounds to 96 million pounds of copper. As a result, World Copper's Technical Advisory Committee believes the Company should investigate the possibility of re-processing the run-of-mine and ISL material for unrecovered copper.
Readers are cautioned that the above historical quantities and grades reported in the McAlester production report and MSRD report have not been verified by the Company and there has been insufficient work to determine if the numbers in the historical reports are accurate. The potential quantity and grade of copper at the historical heap leach pads and ISL area is conceptual in nature, there has been insufficient exploration to define a mineral resource and it is uncertain if further exploration will result in the target being delineated as a mineral resource. The Company is not treating the opportunity target as current mineral resources or mineral reserves.
Given that the heap leach pads are on private patented land, they are readily accessible from a permitting perspective. To confirm the quality of the mineralized material for re-processing, the Company expects to complete a confirmatory drilling programme and metallurgical testing on the leach pads to confirm the volume, grade, and mineralogical characteristics of the material and to estimate the potentially recoverable pounds of acid-soluble copper. If the grade and mineralogical characteristics of the historically mined material is confirmed through the results of the exploration program, the Company will also analyze if the mineralized material could be processed before any potential future mining of the bedrock resources.
Gord Neal, CEO, said, "The prospect of re-processing historically mined mineralized material would add more value and provide additional upside to the Zonia Project, and it is a unique potential value opportunity. In mining projects, any opportunity to start production early and to generate revenue right from the start of the operations, can greatly improve the economics of the project increasing the net present value (NPV) and reducing the financing needs, making the project more robust, and lowering the execution risk."