As the acid moves through the ground it dissolves the copper. It's done in a controlled manner such that you're never running an injection well without being completely surrounded by recovery wells that capture all the solution. This is all straight off the shelf technology from the uranium industry. There are some differences, but for the most part, they are the same.CIN: Are there any specific deposit types that are best suited to ISR mining? How do you know if ISR mining is the right type of mining for your deposit? ST: ISR is such great technology, and it produces such great economics that people say, "if it's so good for copper why doesn't everyone do it?" The reason is they can't. You need a very special deposit. Although the mineralization is not different from other copper oxide deposit, we can use ISR because our deposit sits below the water table, is naturally highly fractured, and the oxidized copper is sitting right on the fractured surfaces. These are unusual aspects of copper oxide deposits suitable for in-situ leaching which occur in Arizona more than anywhere else in the world. At one time, our deposit was sitting at surface. However, there was a large tectonic event in the Southwest United States called the Basin and Range faulting that essentially dropped our copper deposit down into a chasm and covered it over with dirt. The result was a highly fractured, oxidized, copper deposit sitting below the water table. CIN: What are the advantages of ISR mining for copper? ST: There are lots of advantages. First of all, there are a whole slew of environmental advantages, one of the biggest being that we can completely rehabilitate the mine when we are finished. If you compare ISR mining to open pit, once you finish mining an open pit, there's a big hole in the ground and a big pile of waste sitting next to it. Often the open pit fills up with water and it becomes acidic, which can create acid mine drainage problems. With our mining, all we're doing is drilling wells. So once we finish mining in that area, we flush that area with fresh water, which flushes out any remaining acid. Once the acid has been flushed out, all we have to do is rehabilitate the wells by filling them in and taking off the top of the well so nothing remains above ground. At this point, the land can be re-used for whatever purpose you like - farming, housing development or industry. It's completely rehabilitated; there's no negative - the whole mine site is not out of bounds for the rest of time. It's low impact.
And of course there are other things we don't need like dust suppression, because we don't make dust. We don't use explosives, or make a lot of noise; we don't have a lot of trucks driving around or consume huge amounts of diesel or electric. We have a very low environmental impact because we don't do any of those things and we recycle nearly all of our water.CIN: On the other side of that, are there any associated risks for Excelsior with ISR? ST: In our particular mining environment, there's no substantial risk. It has been consistently demonstrated that this type of mining can control the solution so that it doesn't leak. Furthermore, in our particular case, there are carbonate rocks around our deposit so if anything did leak, it would be immediately neutralized by the carbonate. We believe the Gunnison project to be the most environmentally friendly copper mining project in existence today; it is the closest thing you will ever find to a green mine. From a mining point of view, it's low risk because it's low cost. With in-situ mining, because your margin is so great, if the copper price drops you can still be in business. The low cost of the operation provides tremendous risk-management. CIN: Are there any companies that compete with the Gunnison project? ST: The short answer is no; there are no companies that I'm aware of that have the same sort of economic outcome that we have. The combination of low capital and low operating costs and IRR pretty much puts us well ahead of any of the competition. There is another in-situ project in Arizona, Florence Copper, they are also at the prefeasibility level. CIN: According to the prefeasibility, the project has a copper recovery rate of 47 percent. How does that compare to industry standards? ST: For industry standard ISR, that number is probably closer to 60 or 70 percent, depending on what you're mining. The reason that we are low is because we apply a recovery factor; we factor our recovery back by a fair percentage because we prefer to be conservative. That means we have greater margin on the upside as we go forward. CIN: What's next for the company? Will you be looking for any additional funding in the near future? ST: What we're doing right now is that we're looking at strategic plans going forward, including options for financing. Our preference is to find a long-term partner for the project - somebody who's got the capacity to see us right through to the end of the feasibility and permitting and even into construction. CIN: Excelsior Mining's prefeasibility study was (very) positively received by the market. In your opinion, do you see that enthusiasm as an indication that investor sentiment relating to the market is improving? ST: I think quality companies with strong projects are going to start breaking away from the pack. Those with the best projects and strong management teams are going to be rewarded in 2014 and we certainly are expecting such an outcome for Excelsior Mining.
Securities Disclosure: I, Vivien Diniz, hold no direct investment interest in any company mentioned in this article.Editorial Disclosure: The Investing News Network does not guarantee the accuracy or thoroughness of the information reported in the interviews it conducts. The opinions expressed in these interviews do not reflect the opinions of the Investing News Network and do not constitute investment advice. All readers are encouraged to perform their own due diligence. Low-cost Copper Mining: Excelsior Mining CEO Talks ISR in Arizona from Copper Investing News