Florence Copper Project
Curis Resources Ltd. - Rustyn Sherer

ImageWhen a mining company comes to town and says - there’s three billion pounds of copper here … and we’re going to mine it.  But don’t fret … we won’t be doing any digging.  We’ll just be pouring sulfuric acid into the ground. 

Whoa!  Hold on there fellas.  Is this safe?  What will you do to our water?  Has this ever been done before?  Will this even work?  We’ve got hundreds of questions …

That’s probably something like the reaction Curis Resources Ltd. got when it announced its copper mining project to the people of Florence, Arizona.  For the last year the company has dedicated much of its energy to educating the public with regard to the myriad of questions regarding its planned mining operation.  Rustyn Sherer was our teacher last Wednesday and he provided us with the “not so scary” facts about how they intend to get the copper out of the ground.

The copper is in a gravel bed under several hundred acres of land just west of Florence and sits between 400 and 1,000 feet below the surface.  During the 1960’s core samples were taken in the area revealing the presence of the copper.  From the 506 core samples mining engineers were able to determine the amount and the exact location of the copper.

The extraction method to recover the copper is called In-Situ Recovery and it’s been used for more than 30 years. The Latin term in-situ refers to the fact that the ore containing the copper remains “in place” – without being taken out of the ground. The copper is in a natural broken up gravel bed so fracturing is not needed. 

The capture of the copper occurs during Phase I of the project when copper combines with sulfuric acid. A dilute sulfuric acid solution (99.7 percent water) is pumped into the ground and flows through the gravel bed. The acid solution is extremely weak … about the same as vinegar or lemon juice.  The solution remains in place for three to five years during which time the copper combines with the sulfuric acid solution.

Phase II begins when the copper solution is pumped out of the ground.  The solution is purified and is ultimately used in an electrolytic process where the copper is deposited on a cathode plate.  The final product is a copper cathode sheet and is 99.999 percent pure copper.

About half of the three  billion pounds of copper in the ground will be recovered.  170 jobs will have been created.  The project will exist for 20 years after which the water in the gravel bed will be returned to its neutral pH level of seven.

Curis is not just a name; it’s an acronym - Copper recovery in-situ

Cu … the symbol for Copper
            r … recovery
                        is … in-situ