Arizona Sonoran Copper Company Inc. announced metallurgical results from the Nuton Phase 1 column leach program from ASCU's Cactus copper porphyry project in Arizona, USA. The Phase 1 scope includes column testing the Cactus sulphides, primary and enriched, using the proprietary Nuton additives for consideration within a traditional heap leach and SXEW mining flow sheet. Testing included a variety of conditions, including operating temperatures and additive schemes.

Pending the completion of a Commercial Framework Agreement, Nuton and ASCU are currently planning a Phase 2 column leach program. Phase 2 would be designed to test and/or mitigate opportunities and threats identified under the Phase 1 test program. On the Cactus deposit, a total of 23 small column leach tests (3 ft | 1 m) on 10 ore types, plus a Life of Asset (LoA) Blend, are currently completed or in progress.

Preliminary test work results indicate that using Nuton additives at elevated temperatures have the potential to significantly enhance chalcopyrite extraction in the LoA blend and the other primary sulphide ore types. The highest copper extraction achieved to date for the LoA Blend is 80%. Condition optimizations, including a higher temperature control for the LoA blend is currently underway, with the target of consistently exceeding 80% extraction rates.

Acid consumption for the primary sulfide ores ranges from 10 to 60 kg/t. For the higher acid consuming ores, increasing the pH appears to have a positive effect on acid consumption, but also a negative impact on the rate of copper extraction. Nuton will continue to analyze residue samples that may yield further insights. Copper extractions from the secondary sulfide dominant ore types at elevated temperatures are very high, ranging from 86% to 98%.

These ores contain very little reactive gangue, consequently most of the ore types are net acid generators.