Pilot well field with Poston Butte in the background.
Courtesy of Florence Copper, Inc.
On 24 July 2018, the Arizona Mining Review team joined Dan Johnson, Vice President & General Manager of Florence Copper, and Stacy Gramazio, Manager of Communications & Public Affairs, for an early morning tour of the pilot in-situ copper recovery (ISCR) facility outside Florence, Arizona.
Florence Copper is in the final stage of deploying a $25 million production test facility, designed to harvest 1.5 million pounds of copper annually for several years. Following successful proof of concept, Florence Copper has plans for a larger plant to recover 55 million pounds of copper annually for the first 6 years, and 85 million pounds annually for another 14 years. Over a 20-year lifespan, Florence Copper estimates the recovery project will yield ~$3.4 billion dollars in revenue.
In-situ copper recovery is a 3-phase process: Phase 1 - injection of the active fluid (99.5% water with 0.5% sulfuric acid) with a pH similar to household vinegar; Phase 2 - extraction of the pregnant, copper-rich solution; and, Phase 3 - using electrowinning, a process first pioneered in the Globe-Miami area in the late 1960s, to produce ~ 100-pound copper cathodes that are 99.999% copper.
