Mining and Refining

9 Articles

Mining And Refining: Lead, Silver, And Zinc

October 2, 2024 by 16 Comments

If you are in need of a lesson on just how much things have changed in the last 60 years, an anecdote from my childhood might suffice. My grandfather was a junk man, augmenting the income from his regular job by collecting scrap metal and selling it to metal recyclers. He knew the current scrap value of every common metal, and his garage and yard were stuffed with barrels of steel shavings, old brake drums and rotors, and miles of copper wire.

But his most valuable scrap was lead, specifically the weights used to balance car wheels, which he’d buy as waste from tire shops. The weights had spring steel clips that had to be removed before the scrap dealers would take them, which my grandfather did by melting them in a big cauldron over a propane burner in the garage. I clearly remember hanging out with him during his “melts,” fascinated by the flames and simmering pools of molten lead, completely unconcerned by the potential danger of the situation.

Fast forward a few too many decades and in an ironic twist I find myself living very close to the place where all that lead probably came from, a place that was also blissfully unconcerned by the toxic consequences of pulling this valuable industrial metal from tunnels burrowed deep into the Bitterroot Mountains. It didn’t help that the lead-bearing ores also happened to be especially rich in other metals including zinc and copper. But the real prize was silver, present in such abundance that the most productive silver mine in the world was once located in a place that is known as “Silver Valley” to this day. Together, these three metals made fortunes for North Idaho, with unfortunate side effects from the mining and refining processes used to win them from the mountains.

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Mining And Refining: Fracking

June 5, 2024 by 52 Comments

Normally on “Mining and Refining,” we concentrate on the actual material that’s mined and refined. We’ve covered everything from copper to tungsten, with side trips to more unusual materials like sulfur and helium. The idea is to shine a spotlight on the geology and chemistry of the material while concentrating on the different technologies needed to exploit often very rare or low-concentration deposits and bring them to market.

This time, though, we’re going to take a look at not a specific resource, but a technique: fracking. Hydraulic fracturing is very much in the news lately for its potential environmental impact, both in terms of its immediate effects on groundwater quality and for its perpetuation of our dependence on fossil fuels. Understanding what fracking is and how it works is key to being able to assess the risks and benefits of its use. There’s also the fact that like many engineering processes carried out on a massive scale, there are a lot of interesting things going on with fracking that are worth exploring in their own right.
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Mining And Refining: Tungsten

April 2, 2024 by 16 Comments

Our metallurgical history is a little bit like a game of Rock, Paper, Scissors, only without the paper; we’re always looking for something hard enough to cut whatever the current hardest metal is. We started with copper, the first metal to be mined and refined. But then we needed something to cut copper, so we ended up with alloys like bronze, which demanded harder metals like iron, and eventually this arms race of cutting led us to steel, the king of metals.

But even a king needs someone to keep him in check, and while steel can be used to make tools hard enough to cut itself, there’s something even better for the job: tungsten, or more specifically tungsten carbide. We produced almost 120,000 tonnes of tungsten in 2022, much of which was directed to the manufacture of tungsten carbide tooling. Tungsten has the highest melting point known, 3,422 °C, and is an extremely dense, hard, and tough metal. Its properties make it an indispensible industrial metal, and it’s next up in our “Mining and Refining” series.

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Mining And Refining: Titanium, Our Youngest Industrial Metal

December 5, 2023 by 9 Comments

Earlier in this series, we made the case for copper being “the metal that built technology.” Some readers took issue with that statement, noting correctly that meteoric iron and gold were worked long before our ancestors were able to locate and exploit natural copper outcroppings, therefore beating copper to the historical punch. That seems to miss the point, though; figuring out how to fashion gold decorations and iron trinkets doesn’t seem like building the foundations for industry. Learning to make tools from copper, either pure or alloyed with tin to make bronze? Now that’s how you build an industrial base.

So now comes the time for us to make the case for our most recent addition to humanity’s stable of industrial metals: titanium. Despite having been discovered in 1791, titanium remained locked away inside abundantly distributed ores until the 1940s, when the technological demands of a World War coupled with a growing chemical prowess and command of sufficient energy allowed us to finally wrest the “element of the gods” from its minerals. The suddenness of it all is breathtaking, too; in 1945, titanium was still a fantastically expensive laboratory oddity, but just a decade later, we were producing it by the (still very expensive) ton and building an entirely new aerospace industry around the metal.

In this installment of “Mining and Refining,” we’ll take a look at titanium and see why it took us over 11,000 years to figure out how to put it to work for us.

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Mining And Refining: Cobalt, The Unfortunately Necessary Metal

October 18, 2022 by 21 Comments

The story of humankind is largely a tale of conflict, often brought about by the uneven distribution of resources. For as long as we’ve been down out of the trees, and probably considerably before that too, our ancestors have been struggling to get what they need to survive, as often as not at the expense of another, more fortunate tribe. Food, water, land, it doesn’t matter; if They have it and We don’t, chances are good that there’s going to be a fight.

Few resources are as unevenly distributed across our planet as cobalt is. The metal makes up only a fraction of a percent of the Earth’s crust, and commercially significant concentrations are few and far between, enough so that those who have some often end up at odds with those who need it. And need it we do; what started in antiquity as mainly a rich blue pigment for glass and ceramics has become essential for important industrial alloys, high-power magnets, and the anodes of lithium batteries, among other uses.

Getting access to our limited supply of cobalt and refining it into a useful metal isn’t a trivial process, and unfortunately its outsized importance to technological society forces it into a geopolitical role that has done a lot to add to human misery. Luckily, market forces and new technology are making once-marginal sources viable, which just may help us get the cobalt we need without all the conflict.

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Mining And Refining: Sulfur

September 28, 2022 by 23 Comments

When you think of the periodic table, some elements just have a vibe to them that’s completely unscientific, but nonetheless undeniable. Precious metals like gold and silver are obvious examples, associated as they always have been with the wealth of kings. Copper and iron are sturdy working-class metals, each worthy of having entire ages of human industry named after them, with silicon now forming the backbone of our current Information Age. Carbon builds up the chemistry of life itself and fuels almost all human endeavors, and none of us would get very far without oxygen.

But what about sulfur? Nobody seems to think much about poor sulfur, and when they do it tends to be derogatory. Sulfur puts the stink in rotten eggs, threatens us when it spews from the mouths of volcanoes, and can become a deadly threat when used to make gunpowder. Sulfur seems like something more associated with the noxious processes and bleak factories of the early Industrial Revolution, not a component of our modern, high-technology world.

And yet despite its malodorous and low-tech reputation, there are actually few industrial processes that don’t depend on massive amounts of sulfur in some way. Sulfur is a critical ingredient in processes that form the foundation of almost all industry, so its production is usually a matter of national and economic security, which is odd considering that nearly all the sulfur we use is recovered from the waste of other industrial processes.

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Mining And Refining: Helium

June 15, 2022 by 46 Comments

With a seemingly endless list of shortages of basic items trotted across newsfeeds on a daily basis, you’d be pardoned for not noticing any one shortage in particular. But in among the shortages of everything from eggs to fertilizers to sriracha sauce has been a growing realization that we may actually be running out of something so fundamental that it could have repercussions that will be felt across all aspects of our technological society: helium.

The degree to which helium is central to almost every aspect of daily life is hard to overstate. Helium’s unique properties, like the fact that it remains liquid at just a few degrees above absolute zero, contribute to its use in countless industrial processes. From leak detection and welding to silicon wafer production and cooling the superconducting magnets that make magnetic resonance imaging possible, helium has become entrenched in technology in a way that belies its relative scarcity.

But where does helium come from? As we’ll see, the second lightest element on the periodic table is not easy to come by, and considerable effort goes into extracting and purifying it enough for industrial use. While great strides are being made toward improved methods of extraction and the discovery of new deposits, for all practical purposes helium is a non-renewable resource for which there are no substitutes. So it pays to know a thing or two about how we get our hands on it.

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