Dr. Dale Rucker Presents
A Billion Gallons of Experience:
Results from a long term subsurface heap leaching program.
Tuesday Feb 23rd 2016 at 11am.
Many studies have shown that surface leaching of low-grade rubblized ore is generally an effective means to extract nearly 70 to 90% of a heap’s metal content. The last 10-30%, however, has significant economic impacts on the operation, profitability, and eventual closure of the mine. Therefore, any inexpensive means to extract the last bit of metal from the heap can be of great value. Lately, we have been conducting targeted subsurface leaching on copper ore that has historically underperformed due to high fines and compaction. To this end, we recently hit a milestone in our experience: a billion gallons of barren solution injected through a number of wells that targets the underleached ore. Our experience in this endeavor has provided much insight into heap performance, effects of localized phenomena, and the importance of hydraulic and metallurgical monitoring to understand the economic impact of subsurface leaching. In this work, we will discuss many of these experiences and look towards the future as we expand the well field and prepare for closure.