I interviewed Dr. Anthony Mariano in person on 6 July 2007. The following are excerpts from our conversation:
Clint COX: So how did you get interested in rare earths?
DR. MARIANO: How did I get interested in rare earths? I worked in a basic research lab with Kennecott Copper, and at that time, I was an earth scientist. I was able to do anything I wanted in research. One day one of the professors at Boston University, Arthur Brownlow, gave a talk. He had just visited the Fen carbonatite in Norway, and the Alno carbonatite in Sweden. He brought back a suite of rocks. As he talked about the mineralogy and the geochemistry of these carbonatites, I became fascinated with the unusual minerals that occur in carbonatites. Arthur Brownlow ended up giving me all of the rocks that he collected. While working for Kennecott in basic research, I discovered that Kennecott had 50% of the Bond zone, the Oka carbonatite in Quebec. I began working on Oka and conducting research on carbonatites from various world localities that were known to contain rare earths, niobium, and tantalum. Shortly after, the chief geologist from Molycorp, John Bryant at the time, (who used to be an ex-Kennecott geologist), invited me to go to Mountain Pass and look at the deposit. I did some research work on the Mountain Pass mineralogy and geochemistry, and also in rocks from Araxa, another carbonatite in Brazil that Molycorp owned. They invited me there in 1968. I continued to do research work –traveling to Africa, South America, and Canada to look at carbonatites. I became fascinated with the carbonatite at Blue River in British Columbia because of its unusual geologic occurrence in active orogenic environment and because of the high tantalum content. [Blue River is now owned by Commerce Resources].
Rare earths have an intrinsic property that allows you to differentiate carbonatites from non-igneous calcium carbonate or dolomite-rich rocks. I just became fascinated with the rare earths in mineralogy and their total geochemistry and distribution.
COX: And here you are, years later.
DR. MARIANO: Yes. But I’ve extended my expertise to include other rare elements that are often found associated with carbonatites, or alkaline igneous rocks. So I don’t just work on carbonatites. The Pitinga Younger granite, the Younger granites of Nigeria, the Thor Lake granite — they are not carbonatites — but they are enriched in rare elements, which now constitute my area of specialization.
COX: What other elements do you look at? What are some of the other rare metals that you follow?
DR. MARIANO: Titanium is not necessarily rare. It’s an industrial mineral, but it’s often concentrated in beach sands. The mineral apatite may also be concentrated in carbonatites. Agricultural apatite from carbonatites is mined in the Kola peninsula, Russia, extensively in Brazil and in Palabora, South Africa, and Ontario, Canada. I get involved in zirconium also — which can occur in substantial amounts in alkaline rocks and in carbonatites.
COX: How would you describe the present state of the rare earth market, or rare earth mining?
DR. MARIANO: There are so many demands now, particularly dealing with the use of the high field strength magnets in hybrid automobiles, and the use of the rare earths in catalytic converters. There are many unique properties of rare earth elements that cannot be substituted for by other elements. Years ago, people were talking about substituting copper with aluminum, but copper has unique properties, and aluminum could never take over the copper market. This is particularly true with the rare earths. The valence electrons of the rare earths are sub-orbital electrons that occur in a lower shell of the electron configuration of the rare earth elements. This introduces properties to the rare earths that are rather unique, and they’re not replaceable. So the demand is always going to be there. Research work continues to be done where we are constantly finding new applications for the rare earth elements. The outlook for the rare earth market is very good, and it’s going to continue to be — especially since rare earth elements and their utilization are of strategic importance.
COX: What do you see as the greatest risks for the rare earth market?
DR. MARIANO: There are 14 rare earths [promethium (Pm) is not usually counted because it does not occur naturally], 15 including yttrium, and if you want to include scandium, you get 16. The demands for the rare earths are very dynamic. One day there’s a big demand for a certain rare earth and tomorrow that demand diminishes and some of the other rare earths gain greater value. One has to be working on deposits that are enriched in the rare earths that are currently in demand. I think the best solution for that is to have a deposit that has all of the rare earths and the sophisticated technology of separating them and being able to produce high-grade products of oxides or metals. You have to be able to provide the world market demands.
COX: What do you think are the common misperceptions about rare earths? What are some of the things that people just don’t get yet?
DR. MARIANO: One of the big misconceptions in exploration is that people see anomalous rare earths in any deposit that they are working on, and then they immediately think they have a potential economic rare earth deposit. That’s the biggest misconception. Keep in mind that during the 70s and 80s, Molycorp — who pretty much had the rare earth market at that time –- would not look at any deposit if it had less than 2% total rare earths. A number of years later, the Chinese made the innovation where they could mine orders of magnitude less rare earths from the ion-absorbed South China clays, which currently play a very significant role in the world market for rare earths. People may discover a deposit, but they’re not able to make proper evaluations on the worth of rare earth deposits.
COX: How dominant do you think China is right now?
DR. MARIANO: They’re totally dominant. Who else is producing rare earths? Molycorp is going to start building up again later this year, hopefully, but their labor costs may still be very high compared to China. They are working on refining their extraction chemistry skills that can make them very competitive with the rest of the world — and that may be very much to their advantage. Right now, the rare earths are all coming from bastnaesite from Bayan Obo in Inner Mongolia, bastnaesite from Sichuan in China, and the ion-absorbed rare earth clays in South China. Also there may be small amounts of monazite or xenotime that may be coming as a by-product of ilmenite and/or cassiterite mining in Malaysia, Thailand, and Australia. But that’s probably on a very small scale.
COX: What are some of the things that have surprised you the most during your involvement in the rare earths?
DR. MARIANO: Well, the thing that surprised me the most was the ion-absorbed clays. That was a fabulous innovation that the Chinese made. When I was a little boy playing with toys, if they were made in China or Japan, you threw them away. You used them a couple of times and then they broke. I think a lot of Westerners developed the idea — although totally incorrect — that the Asians are very good at copying, but they are not innovators. That is absolutely incorrect. And when you consider the research that Molycorp and Rhone-Poulenc put in to rare earths — they were just totally outdone by the Chinese with that fabulous innovation.
