Welcome to the History of the Earth podcast where we discuss
all things geological. I’m your host, geologist Dick Gibson. There’s been a
long hiatus in my production of this podcast, and I hope to rectify that with
some new episodes. Today’s topic for Episode 376 is U.S. mineral dependency.
It’s a common misconception, perhaps an expression of
“American exceptionalism,” that the United States is self-sufficient in most or
all of the mineral commodities we use in our stuff every day. Nothing could be
further from the truth.
In my book, What Things Are Made Of, published in 2011, I
documented the uses for everything from arsenic to uranium, and where the U.S.
gets its supply of each. At that time the U.S. was self-sufficient, a net
exporter, of only 19 of the eighty-plus commodities the U.S. Geological Survey
tracks. Today, in 2017 the situation is no better – the count is down to 15
items for which the U.S. is a net exporter.
Some of those items are low-value but interesting things
like boron, kyanite, and diatomite. Only three, gold, iron ore, and molybdenum,
are high-value metals.
A lot of the mineral commodities we import are obscure, but
the vast majority of technologically active Americans use them every day. For
example, indium, critical to making flat-panel displays for televisions and
computers, is all imported, mostly from Canada and China. Zinc is a well-known
metal used mostly in galvanizing iron to prevent rust and in brass and bronze
for everything from door knobs to saxophones. In the U.S., 82% of it is imported,
mostly from Canada and Mexico.
What about that vital bomb-making element, uranium? Hardly
any is used to make bombs in the United States any more, but it helps generate
electricity in 61 commercial nuclear power plants across the nation, and almost
20% of our electricity comes from nuclear plants. Where does that uranium come
from? Only about 4% of it is mined in the United States. The rest is imported,
with Canada and Kazakhstan providing close to half, and Russia, Australia, and
Namibia supplying most of the rest.
How about something as common as a flashlight battery?
Dry-cell batteries are made with zinc, carbon, and a pasty electrolyte of
ammonium chloride and manganese dioxide. All the manganese used in the U.S. is
imported, with more than two-thirds of the manganese ore we use coming from
Gabon in Central Africa. By far most of the nearly 700,000 tons of manganese
the U.S. consumes goes to steel alloys, where it helps make the steel resistant
to abrasion and stronger in impacts. That makes it a common alloy in bicycle
frames and mining tools.
Or consider common salt. Even though there are 64 plants in
16 states, with Kansas leading the way in production, the United States still
imports about a quarter of all the salt we use. About half the salt consumed
goes to highway deicing, but a third or so is used to make a wide variety of
chemicals, including plastics like polyvinyl chloride or PVC. Food processing
and common table salt amount to just 3% of the salt used in the U.S. Chile is
the largest source for salt imports, with Canada and Mexico second and third.
The point of my book What Things Are Made Of and this brief
set of examples is simply to help you recognize the profound level of globalization
that exists in everyday products Americans use.
Thanks for listening, and I hope you’ll join us next time
for another episode of the History of the Earth.
—Richard I. Gibson
