Appendix G

This report provides chemical, physical, mineralogical, and microbiological procedures for the analysis of coal overburdens and the resultant minesoils. These step-by-step methods identify and measure rock and soil properties that influence advance planning, mining efficiency, post-mining land and water quality and long range land use.

Resolution Copper Mining Company (RCM), acting jointly with Rio Tinto (RT-OTX), asked Mark Logsdon (Geochimica, Inc, Aptos, CA) to prepare a plan to geochemically characterize the rock mass that may be subject to chemical weathering as a consequence of block-caving operations at The Resolution property near Superior, Arizona. Results from this study will be used by RCM and its contractors to develop a geochemical model of the block-cave zone as it affects operational and closure considerations.

This test method covers a procedure that accelerates the natural weathering rate of a solid material sample so that diagnostic weathering products can be produced, collected, and quantified. Soluble weathering products are mobilized by a fixed-volume aqueous leach that is performed, collected, and analyzed weekly. When conducted in accordance with the following protocol, this laboratory test method has accelerated metal-mine waste-rock weathering rates by at least an order of magnitude greater than observed field rates.

Research was carried out to improve acid rock drainage (ARD) prediction methodologies, focussing on resolving uncertainties in acid base accounting (ABA) methods. Advancements, their application, and interpretation are reported. Consideration of both net acid production potential (NAPP) and net acid generation (NAG) test results provide a more reliable routine screening technique than either test alone, increasing confidence in acid potential classification and identifying apparent conflicts requiring further investigation.

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