Category Archives: History

The Toxco Story – Parts 1 & 2

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This is a guest post written by a good friend and colleague who retired as an executive from the specialty chemical industry. He is an author and editor of a respected book on Grignard chemistry. It is an honor for me to post his recollections on this site with his permission.

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The TOXCO Story – Part I

I suppose this story begins during the Cold War. The US had developed a triad of defense capabilities to deter Soviet aggression. We had the Air Force B-52 bombers armed with atomic weapons, the submarine based Trident missiles, and the land based ICBMs–first the liquid fuel Atlas rockets and later the solid fuel Minuteman missiles hidden is silos in North Dakota and elsewhere.

Then came 1989, the destruction of the Berlin Wall, the subsequent collapse of the Soviet Union and, suddenly, the Russians were no longer the dreaded foes whom we once feared. Maybe it was time to “stand down” our hair-trigger defense posture.

Those solid fuel Minuteman rockets were designed to be launched on short notice. Firing them required a significant amount of electricity. This was to come from the electric power grid. But our military, recognizing that this source of power could be compromised in the tense times leading up to a nuclear confrontation, needed a backup. As a result, each missile silo was equipped with a diesel powered electric generator, just in case.

But things could go wrong. The diesel fuel might be contaminated, or sabotaged by Russian saboteurs, or any of a number of other problems. So, in an overabundance of precaution, the military insisted on a “backup to the backup”. And what could be better or more reliable as a source of electricity, than a battery. To be sure, these would have to be BIG batteries, bigger and more powerful than any produced thus far, but they would be certain.

And so, the Defense Department commissioned the production of the world’s largest and most powerful batteries. These were based on lithium-thionyl chloride chemistry[1]. Each primary cell contained sheets of elemental lithium, surrounded by gallons of thionyl chloride, a reactive liquid which on contact with water produces a mixture of sulfuric acid and hydrochloric acid—really nasty stuff. These primary cells were each about the size of a coffin and it took three, ganged together to generate the power needed to initiate a missile launch. The government contracted for thousands of them and Union Carbide supplied them.

Apparently, at some point, there was a fatal incident involving a 10,000 amp Minuteman battery being drained and replaced[2] and this contributed to a decision in the early-mid 1990s to dispose of these hazardous items. The DOD issued a Request for Proposals (RFP) which caught the attention of a group of businessmen and entrepreneurs in southern California.

Operating in Orange County, California, headquartered in Anaheim, near Disneyland, were three affiliated companies. Adams Steel was in the ferrous metal recycling business-old washing machines, refrigerators, scrapped cars. Before you scrap a car, you remove the lead-acid battery and the catalytic converter. The battery, containing lead metal, lead salts and sulfuric acid is a hazardous waste and its disposal is regulated by the EPA. The catalytic converter contains precious metals such as platinum, rhodium and iridium. These two items (batteries and catalytic converters) were handled by Kinsbursky Brothers. Non-ferrous metals (common ones such as copper and aluminum and non-common ones like tantalum and gallium from electronic devices) were processed by Alpert & Alpert. The companies had worked together for a number of years.

Principals at Adams Steel and Kinsbursky decided to form a joint venture to bid on the lithium battery disposal opportunity. They created TOXCO for this purpose. It was headed by Terry Adams (the youngest sibling in the Adams family) and Steve Kinsbursky. And they won the bid. The government would pay TOXCO millions of dollars to dispose of these batteries that the government had paid millions of dollars to manufacture some years earlier. Your tax dollars at work.

So, how do you dispose of a lithium-thionyl chloride cell weighing hundreds of pound and filled with dangerous and explosive ingredients? Well, if you are a mechanical engineer, trained at USC (as Terry Adams was), you take a mechanical engineering approach the problem. You have to neutralize the thionyl chloride and the lithium by reaction with water. And reactions take place more slowly (and more safely) at lower temperatures. So, the answer is to chill the cell in liquid nitrogen down to 77°K, put it in a large container filled with water and chop it apart with big mechanical knives (like you chop an automobile into small pieces for scrap). This actually works. Provided you’re certain that the cells have been fully discharged first. But don’t take the military’s word for it. If you do, there may be an embarrassing incident, as there was in 2000, during the disposal process.[3]

Next question. Where do you do this disposal? The TOXCO team discovered that there was an underused industrial site in Trail, British Columbia, on the Canadian side of the Idaho border. It had been part of the Cominco Smelter operations and was one of the most heavily polluted sites in North America[4]. What better place to site a hazardous battery disposal plant? If something went wrong, who would notice?

And so, TOXCO went into business, disposing of lithium batteries, successfully (except for a few incidents like the one incident alluded to above).

One of the by-products of this process was a stream of aqueous lithium salts. These had value and could be recovered and that put TOXCO into the lithium chemicals business. But that’s part II of this story.

The TOXCO Story – Part II
(the Lithchem Story)

This story also begins in the Cold War. Even as the atomic bomb (the uranium and the plutonium fission bomb) was being engineered into reality at Los Alamos in the mid 1940s, plans were being made for the next generation weapon—a fusion bomb.

The first H-bomb, based on the concept of fusing light nuclei, was tested at Eniwetok in the South Pacific in 1953. Improvements in the initial “clunky” design quickly followed. One way to boost the power of the explosion was to surround the core of the bomb with a layer of lithium deuteride, LiD. Lithium is, well, the element lithium, atomic number 3 in the Periodic Chart. And deuterium is the name for “heavy hydrogen”, an atom of hydrogen, atomic number 1, but also containing an uncharged neutron[5]. Provided that the lithium used was of atomic weight 6, the fusion of the lithium(6) and the deuterium(2) would produce two nuclei of helium(4), plus lots of energy.

This would only work if you used lithium-6. Unfortunately, the lithium available to us on this planet in mineral form, deposited around the globe, is a mixture of lithium-6 and lithium-7 (the same element, but with one extra neutron). And God, in His infinite wisdom, chose to endow the earth with mostly lithium-7. Of the naturally occurring deposits of lithium, 93% is lithium-7.

So, if you need to use just Li-6, you have to separate it out from the more abundant, naturally occurring Li-7. And the US government proceeded to do just that. Starting in the 1950s, they processed millions of pounds of lithium containing minerals to extract the less abundant isotope that was required for its military purpose. For every hundred pounds of lithium salt they processed, they got, at most, 6 pounds of lithium-6 salt[6].

And what do you do with the “leftover” 94+ pounds. Well, you can’t just turn it back into the lithium chemicals marketplace. For one thing, it’s “depleted” lithium (missing its naturally occurring share of Li-6.) This would be easily noticed by someone using the lithium for routine chemical purposes. The extent of “depletion”, that is, of extraction of the Li-6 would be measureable, and that information was a secret[7]. Moreover, if the quantity of depleted Li were ever realized, that number could be used to infer the number of LiD containing bombs, and that too was a secret.

So, for more than five decades, for more than half a century, the US government simply stockpiled the “by-product” depleted lithium in a warehouse, in the form of the simple salt, lithium hydroxide monohydrate, LiOH•H2O. Millions of pounds of it. Packaged in poly lined, 55 gallon fiber drums.

In later years, the cardboard drums began to deteriorate. Some of them were damaged during handling and relocation. Sometime in the 1980s the decision was made to repack the inventory in bright yellow steel “overpack” drums.

Now comes the early 1990s. The Cold War is over. Our nuclear secrets, at least those from the 1950s, are far less precious. And the Clinton administration is looking through Fibber McGee’s closet[8] to see what can be disposed of, and maybe generate a revenue stream for the government in the process.

What they discover is 100,000,000 pounds of “depleted” lithium hydroxide monohydrate, with a potential market value approaching $1 per pound. And so, it goes out for bids.

The terms of the sealed bid auction were that the final sale would be split 70-30 between the highest bidder (who would get 70% of the inventory) and the second highest bidder (who would get 30%, but at the high bid price).

This was a perfect set up. At that time there were only two lithium companies operating in the US who could handle this quantity of inventory—Lithium Corporation of America[9] and Foote Mineral Company[10]. And both of them knew that there was no incentive for overbidding since even the loser would get 30% of the supply.

And that’s where Lithchem appeared on the scene. The TOXCO team was already in the “recovered lithium” business. All they had to do was bid one penny more per pound than the other two majors and they would be awarded the lion’s share of the inventory. They incorporated Lithchem for that purpose. I’m told that LCA and Foote each bid the same number, somewhere in the 20+ cents per pound range, and Lithchem bid one cent more. As a result, Lithchem became the proud owner of 70,000,000 pounds of depleted lithium hydroxide monohydrate.

Now what? The principal use of LiOH is in the manufacture of high performance lithium greases, used in heavy industrial applications-heavy trucks, railroads, etc. Much of the market for lithium greases is in the third world and quality is less of a concern than price.

Still, to be sold on the open market, the LiOH from the government stockpile had to meet certain specifications. Some of the yellow drums contained beautiful white crystalline powder. Others contained dead cats and cigarette butts. It was “government quality” inventory.

One condition of the bid was that the winning bidder had to remove the inventory from its location in a government warehouse (in southeast Ohio[11]) within 12 months of the successful bid. I had the occasion to visit that warehouse, before the stock was removed and it was a memorable sight.

If you recall the final scene in the movie “Raiders of the Lost Ark”, the Ark of the Covenant is being stored in a gigantic government warehouse, filled floor to ceiling with identical gray boxes. A warehouse stretching far into the next county. Now replace those gray boxes with yellow overpack drums, stacked 6 or 8 high, stretching far into the next county. That’s what it was like. That’s what 70,000,000 pounds of LiOH hydrate looked like.

[1] The lithium – thionyl chloride primary cell has a high voltage (3.5 V) and a high current density.

[2] Battery Hazards and Accident Prevention,  By S.C. Levy, P. Bro

[3] In November 2009 a fire broke out at the Trail BC facility in a storage shed containing lithium batteries slated for disposal. It was their sixth fire in fifteen years. Prior to that, a major fire in 1995 destroyed 40,000 kg of batteries at the facility. Three fires occurred in 2000, including one caused by some lithium batteries. This was during the summer when negotiations were underway between Toxco and Atochem for the acquisition of the Ozark business. http://www.cbc.ca/news/canada/british-columbia/trail-battery-recycling-fire-leaves-questions-1.805780

[4] http://en.wikipedia.org/wiki/Teck_Resources

[5] Elements with the same atomic number but different weights are called isotopes. Heavy hydrogen (with an atomic weight 2) is an isotope of hydrogen (atomic number 1). Another example is carbon-14, useful for radiocarbon dating. It’s a heavier version of the more common version of carbon, C-12.

[6] Actually less than 6 pounds. The extraction process was less than perfectly efficient. The actual yield of Li-6 was a closely guarded national secret.

[7] In depleted lithium (with the Li-6 removed), the relative abundance of lithium-6 can be reduced to as little as 20 percent of its normal value, giving the measured atomic mass ranging from 6.94 Da to 7.00 Da.

[8] http://en.wikipedia.org/wiki/Fibber_McGee_and_Molly#The_Closet

[9] Acquired by FMC in 1995 and now known as FMC Lithium.

[10] Now part of the Chemetall Group, a division of Rockwood Holdings.

[11] At the time, it was stored at the DOE enrichment facility in Portsmouth, Ohio.

Russian World

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An interesting question and answer piece has come out signed by Mykhailo Zahorodnii, Ukrainska Pravda. Zhyttia, titled (by Yahoo) “The atrocities committed by the Russians are their reaction to the fact they are nobody in their own country“. It is not a dispassionate bit of analysis by a senior historian, but rather by an experienced reporter from Ukraine. Yes, it is anti-Russian. It does not attempt to convey sympathy or fairness towards the Russian people. But, as one-sided as it is, I think that many valuable insights are made into the consequences of Russian history and also its politics over the last 30 years.

“And it [the Russian army] is doing the same thing to Ukraine as to Syria. That is, it is  technically possible to turn every Ukrainian city into Aleppo. There are orders, there is no honour, there is no dignity, there are no human values.”

If Ukraine is to lose the war, then Russia should be made to pay dearly for it. However, Putin has stated Russian nuclear doctrine- they will only use nuclear weapons if the survival of the state is threatened. This is widely held to be true. The big question is, who decides what the existential threat to the state looks like? Putin decides, of course. This is why the US and Europe must avoid a ham-fisted foreign policy with Russia. The Russian president is a belligerent madman in charge of a nuclear state and whose fantasies about Russian manifest destiny are his guide. Tensions with Russia are here to stay for many years. Putin supported Trump for a reason. Trump “respected” Putin for unknown reasons. We need to keep American madman and rogue narcissist Trump and his ilk far away from foreign policy.

Uranium Town: Uravan, Colorado

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The town of Uravan, Colorado, shows up on maps and road signs. You might think it is a physical town. It sits north of Naturita (pronounced natter reeta), CO, on Hwy 141 about 15 miles up the narrow San Miguel River valley. If you look at it’s Wikipedia page, you’ll see a picture of a bare area of ground. Today all that remains at the surface is a ball field and picnic tables. Every bit of the town and the mill has been demolished, shredded and buried within the confines of a Superfund site. Even contaminated bulldozer blades were buried on-site. Also remaining is a Umetco commercial building. Umetco, a Dow Chemical subsidiary, was responsible for managing the reclamation of the site which lasted from 1987 to 2007.

Main uranium deposits in the US (DoE Office of Legacy Management, 2015)

The local topography consists of sandstone canyons and mesas. The map below (north is up) shows a large area of land west of the valley mill site and up above on Club Mesa. This is the location of buried mill tailings and other contaminated materials. The major radiological contaminant is Radium-226 and its daughter products. Radium is a common and troublesome constituent in uranium-bearing ore.

As an aside, I would recommend taking Colorado Hwy 141 from Naturita north through Gateway enroute to Grand Junction if you’re in the area. Truthfully, Uravan isn’t along the route to somewhere most people would want to go except for locals. This stretch of road is called the Unaweep-Tabeguache Scenic Byway and is absolutely gorgeous. Just like in nearby Arches and Canyonlands National Parks, red sandstone is the dominant country rock in that part of the Colorado Plateau. You’ll drive through breathtaking canyons of red sandstone along the Dolores River, south of Gateway.

During its post-WWII heyday, the company town of Uravan, CO, was one of a number of thriving yellowcake boomtowns in Wyoming, Utah, Colorado, and New Mexico. Overall, there were over 900 uranium mines in operation. The name “Uravan” comes from the URAnium-VANadium ore that was processed there. Uravan was one cog in a large wheel of uranium production first for the Manhattan Project then for the Atomic Energy Commission..

Uravan produced concentrate which was was trucked to Grand Junction, CO, to the Climax Uranium Mill for further processing. Activity at the Climax site began in 1943 for uranium procurement and processing of vanadium mill tailings for uranium.

An excellent timeline of uranium history in western Colorado can be found at the Museums of Western Colorado web site.

Uravan Mineral Belt (Wikipedia)

The earliest mining activity at what became Uravan was for radium recovery beginning in 1912 and falling off by 1923. By 1935 the mill was expanded for vanadium recovery and from 1940 to 1984 the mill was used to process uranium and vanadium.

The predominant ore that was processed at Uravan was Carnotite with a nominal composition of K2(UO2)2(VO4)2·3H2O with variable waters of hydration. Elemental uranium is a dense silvery metal that oxidizes in air, reacts with water and dissolves in oxidizing acids. It has two important oxidation states: the +4 uranous oxidation state which is green and the +6 uranyl oxidation state, UO22+, which is yellow. The uranous form is found in the UO2 mineral Uraninite and the uranium silicate Coffinite. The uranyl vanadate form is found with potassium cation in Carnotite, with cesium in Margaritasite, and with calcium in Tyuyamunite.

Yellow carnotite ore (Colorado Geological Survey)

Uranium-vanadium rich sandstone is found in Club Mesa to the west and just above the town of Uravan. This occurrance is part of the larger Uravan Mineral Belt which encompasses local commercial grade uranium ore. The mesa covers 6 sq miles and is bounded by the San Miguel River, the Dolores River, Saucer Basin and Hieroglyphic Canyon. According to the United States Geological Survey (USGS), the average grade of the ore ranged from 0.25 to1.5 % U3O8 and 1.5 to 5.0 % V2O5 (ref 1).

From an extensive drilling study by the USGS, the Salt Wash member of the Morrison formation sandstone of the late Jurassic age was found to be the host for most of the commercial-grade (in 1957) uranium-vanadium in the Club Mesa area.

Beginning in 1936, the mill site was owned by US Vanadium Corporation and built up to process vanadium ore. An entire town was constructed on site to accommodate workers. It also produced a uranium oxide side-stream as a yellow pigment. Then along came the nuclear age.

References

(1) Results of US Geological Survey Exploration for Uranium-Vanadium Deposits in the Club Mesa Area, Uravan District, Montrose County, Colorado, Boardman, Litsey, and Bowers, May, 1957, Trace Elements Memorandum Report 979.

American Devolution

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It used to be that I couldn’t understand how the Nazis came into power with Hitler appointed as chancellor of Germany in 1933 and how in the ensuing years the German people could support the foul rhetoric and authoritarian nature of the Nazi Party. What kind of mindset did people have then? Now it’s not such a mystery. History isn’t repeating itself exactly, but there is a definite rhyme to it.

Eclipsing Casper, Wyoming

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I found myself up north in Casper, Wyoming, with friends for the 8/21/17 solar eclipse. We were modestly equipped for the spectacle. A member of our small group brought a Celestron 8″ Cassegrain telescope with solar filter and clock drive. We set up in an uncrowded neighborhood and began the wait.

Knowing that Casper would be crowded I had arrived 2 days early to explore some of the local geology. Jeez- I guess that makes me a geotourist. This activity gives a person a mission to complete. Pick some locations to visit and go do it within your time constraints. There is a beginning, a middle, and an end. Success consists of finding the location of interest, getting samples and photographs of unique rocks, stata and general landforms.

I’ve had good luck with the Roadside Geology series of books by Mountain Press Publishing. In the case of the eclipse trip, I secured a copy of the Roadside Geology of Wyoming ahead of time at a local Barnes and Noble. These books are quite well written and illustrated, especially important if you’re not packing a degree in geology.

The unique value of the Roadside Geology books is that the content is divided into state regions then subdivided into stretches of highway that you can drive along. Commonly along the highway can be seen many large-scale features described in the book. Even better, photographs and diagrams of road cuts are frequently highlighted. In hilly or mountainous regions there are many road cuts that allow you to view underground features.

Lately I’ve taken to wearing a yellow reflective vest along the roadside while taking a close look at the exposed formation. People don’t expect to see some yay-hoo walking along the road with a hammer and a notebook as they careen around the curves on a mountain road. Best not to surprise drivers.

Teapot Rock north of Casper, Wyoming.

There is a bit of interesting US history attached to the geology of the Casper area. The Teapot Dome scandal erupted during President Warren G. Harding’s administration in 1922. Harding’s Secretary of the Interior, Albert Bacon Fall, was caught taking bribes in exchange for awarding oil rights to a subsidiary of the Sinclair Oil Company.  The oil field was within the Navy Petroleum Reserve north of Casper.

“Teapot” Dome takes its name from Teapot Rock– a formation that, at the time, had a feature that resembled a spout. This feature is no longer there. “Dome” comes from an anticline fold in the oil bearing strata below. It is part of the larger Salt Creek Oil Field.

The seeing in Casper was good right up to the back third of the eclipse. The Celestron was rigged to throw an image onto a white screen. A chain of sunspots were visible early in the eclipse. As I was equipped with only my Samsung 6 for photography, I did not manage to get great pictures, nor was it really my intent. Sometimes you have to put the camera down and look. Just before totality we saw Baily’s Beads and the diamond ring. The autofocus of the Samsung was unable to produce a sharp image of the beads on the projection owing to the low light level.

Close-up of sunspots early in the eclipse.

When totality arrives you can look at it directly with the naked eye. It’s best to view it without the distraction of equipment. During totality it became noticeably cooler. The eclipsed sun had a wispy corona around it, reaching into space. Around the horizon back on the ground was a beautiful 360 degree sunset. People in the neighborhood were cheering. What a thing to see.

 

Pinhole projection using aluminum foil and a cereal box.

Here you can see some knucklehead trying to get a view through a pinhole projector cleverly disguised as a box of corn flakes. He commented that the image was only slightly better than nothing. In fact, the image projecting through a colander onto the pavement was superior (below).

Multiple images of eclipse as projected through a colander.

 

US Russian Policy is Pathetic

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I just have to say that in regard to the deteriorating situation with the Soviet Union Russian Federation, it does not appear that either the EU or the US have their best thinkers working on it. I think US leaders have misunderstood Putin from the beginning and I see very little to convince me that Obama’s people, the Congress, or any other high level functionaries known to me have a clue how to get their arms around Russian behavior or a workable diplomacy.

Certainly recent (post-Ford) US incursions into foreign lands with troops or drones have taken us off the moral high ground in this regard. How can the US lecture Russia on the invasion of Crimea when we invaded Iraq based on lies, subterfuge, and outright errors?

Bush 43 and Clinton had historical opportunities to gain better alliance with Russia. But we supported Yeltsin in the Clinton years and ignored Putin’s offers of assistance after 9/11. The Russian people were mystified when the US supported Yeltsin, widely regarded as a drunken buffoon. Gorbachev’s memoirs paint a lackluster and untrustworthy picture of Yeltsin.  And the US has done nothing but confirm Putin’s paranoia about US intentions by adding membership to NATO, ABM’s in Poland, petroleum wars in the middle east, and the general appearance of weakness by in-house political fratricide.

We have no use for milquetoast administrations like Obama’s, nor do we need rabid swingin’ dicks like John McCain or his hawkish brethren. We do need Russian and Slavic scholars who speak the language and understand the history of Russia at least back to Peter the Great. They can be immigrants from former Soviet territories of the ilk of Zbigniew Brzezinski, Madeleine Albright, or even a world savvy guy like Henry Kissinger. Who are the current brain trust for eastern European politics and is the CIA giving them good intelligence? Did the CIA predict the takeover of Crimea?

Getting the pay out of pay dirt

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This is an excerpt from a writing project I’m working on.

The impulse to find and extract gold and silver was one of the drivers of 19th century westward expansion in North America.  The discovery of gold in a California stream bed in 1849 and the subsequent discovery of gold and silver in other territories eastward to Pikes Peak and the Black Hills resulted in waves of migration of prospectors, merchants, investors, and swindlers from all directions, including Europe.

The staking of mineral claims in the American west by people who were engaged in the extraction of mineral wealth lead to an inevitable avalanche of settlers interested in tapping some of the wealth of the miners themselves. The open territory created a void that was filled by industrialists, merchants, government, and perhaps most importantly, the railroad. Miners needed supplies and their ore concentrates required transportation and beneficiation.

As claims were made on valuable mineral deposits, the outline of the geographical distribution of mineral value in a region eventually defined what came to be known as a district. The expansion of the railroad, sweetened by land grants, added permanence to the settlement of many regions around and en route to the mining districts.  The simple logistical requirement of frequent stops to fill the steam locomotive with water lead to the establishment of towns along the railway. This expanding transportation network, along with liberal access to land, lead to settlement by farmers and ranchers who then created a demand for goods exported from long distances by rail.

The history of man’s fascination with gold and other metals is well documented and there is no need to reiterate that saga in the present work. The mania for gold and silver in the west is legendary. Indeed, clues to the history of gold and silver mining in the American west are quite apparent even to the casual observer today. A drive to Cripple Creek or Central City in Colorado will take the motorist past a great many long abandoned mine dumps, prospect holes, adits, and antiquated mineshaft head works. These quiet features of the landscape mark the location of what was in times past a great and bustling industry.

Throughout the American west today there are many “tourist mines” and mining museums operated by individuals and organizations who recognize the importance of keeping this part of our cultural heritage alive. Through their efforts, visitors can view 19th century mining technology on site and experience the dark and eerily silent realm of the miner. Visitors can see for themselves the intense and sustained effort required in hard rock mining and the occupational hazards miners were exposed to.

The tourist mines and museums often focus on the activity of mining itself as well as the specialized equipment needed to blast the rock and muck it out of the mine. This is only natural. The gold and silver rushes left behind a large number of artifacts. These items are of general interest to all.

The technology that is often glossed over relates the matter of getting the pay out of the pay dirt. Indeed, this is a central challenge to gold and silver extraction. Once the streams have been depleted of placer gold and the vein or lode has been discovered somewhere up the mountainside, the business of extracting gold or silver from hard rock becomes technically much more challenging and capital intensive.

The panning and sluicing of placer or alluvial gold, while labor intensive, is conceptually easy to grasp. High density gold particles can be transported by suspension in a water slurry of the water is moving sufficiently fast. Gold particles will tend to settle at low points in a crevice or a gold pan where the stream velocity slows. A gold pan or the bend in a stream for that matter will have a flow gradient that will tend to collect the gold particles where the stream velocity slows.  A sluice or a Wilfley table are just devices designed to trip laminar fluid flow by inducing turbulence to encourage the denser gold particles to settle. Riffles or channels serve to concentrate the gold particles.

While gravity and clever tricks with fluid flow can be used to collect placer gold, isolating gold or silver from a hard rock ore body is quite a different challenge.  Gold and silver may exist in reduced form within the ore. They may also be found alloyed with one another or otherwise combined with other heavy elements. While gold tends to be inert even under oxygenated conditions near the surface, silver is subject to more facile oxidation and may be found in ionic form with several anionic species. Thus technology for the isolation of gold may not serve as an exact template for silver extraction and isolation.

Gold or silver may exist in the metallic form as bodies visible to the naked eye within the solid rock. Or they may be dispersed in microscopic elemental form throughout the ore body. Gold ore may be rich in elements that complicate its isolation even though the gold is in reduced form.  Silver ore is commonly found in ionic form and with numerous ionic base metals present.

Disseminated gold or silver, that is, gold and silver found dispersed in an ore body, were subject to considerable variation in mineral composition. As a result, differences in isolation techniques and process economics arose among the various operations. Today cyanidation predominates with these ores.

In the 19th century a considerable body of chemical knowledge evolved as the gold and silver rushes progressed. This chemical knowledge was put into practice largely through the efforts of mining engineers.  It was not uncommon for the mining engineer to conceive of what today would be considered a process chemistry change, draw up plans, press the ownership for funding, and put the change into operation.

Twenty-first century chemists may recognize much of the nomenclature from this period as well as the intended inorganic transformations. However, the older literature is filled with obsolete nomenclature or that which is confined to the mining industry.  What should be apparent to the observant reader is the level of sophistication possessed by 19th century metallurgists and engineers in what chemists today might refer to as the “workup”.  That is, the series of isolation steps used to remove undesired components to afford a reasonably clean metal product. Mining engineers refer to this as beneficiation or as extractive metallurgy. Beneficiation of lode gold and lode silver involved chemical transformation in batch or continuous processing.

The story of the development of extractive metallurgy is in part the story of redox chemistry on complex compositions like rock. In the mid 16th century Europe, key individuals like Biringuccio, Agricola, and Ercker began to capture mining and extractive metallurgical technology in print. Vannoccio Biringuccio (1480-1539) published his De la pirotechnia in 1540, detailing economical methods of metallurgy and assaying. In 1556, the work of Georg Bauer (“Agricola”, 1494-1555) was published posthumously. His De re metallica is regarded as a classic of metallurgy. Agricola’s book describes the practical issues related to mining, smelting, and assay work and is illustrated with remarkable woodcuts.

By the year 1520, do-it-yourself books like Ein nützlich Bergbüchlein (A useful mountain booklet) and Probierbüchlein were beginning to appear in Europe describing basic mining and metallurgy techniques.[1] By this time methods of cupellation and the separation of gold and silver were committed to print.

Cupellation is an assay technique wherein crucibles made of bone ash were used to fire prepared gold ore samples with an oxidizer, affording base metal oxides which then separated from the gold and absorbed into the crucible to afford an isolated button of gold.

[1] Aaron J. Ihde, The Development of Modern Chemistry, 1964, pp 22-24; Dover Reprint 1984, QD11.I44, ISBN 0-486-64235-6.

Blogopithocene Man Smelts Tin. Meh.

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The problem of the origin of Cu:Sn bronze has intrigued historians for many years. Bronze artifacts have been dated to 5000 BCE on the Iranian Plateau.  It is thought that the earliest bronzes were arsenical in nature. The presence of arsenic in copper metal or copper ore is not uncommon.

Copper can be found as the native metal but the smelting of copper ore appears to date back to ca 5000 BCE in southeastern Europe in what is now Serbia.

Most commonly today, the word bronze refers to a range of copper alloys comprising various proportions of copper (major, e.g., 88 %) and tin (minor, e.g., 12 %).  As the tin content increases, the resulting alloy changes properties and may have a unique purpose and name. For instance, a ratio of ca 2:1 :: Cu:Sn is called speculum and was prized for it’s ability to take a high polish for mirror applications.

Further down the composition range are varieties of pewter which are alloys comprised substantially of tin and a few percent of copper and antimony for hardening.  Many specalized compositions of pewter have been developed. Britanium or Britannia metal is an alloy comprised of 93 %Sn, 5 % Sb, and 2 % Cu. This alloy serves as the base metal Oscar Award Statue upon which gold is plated.  Pewters composed of Sn:Pb were commonly used as well.

Tin is not found in the metallic state in nature. It is oxophilic and occurs primarily as the tin (IV) oxide mineral, cassiterite. Tin ore was mined in Cornwall, England, for instance, for many centuries before recorded history.  Today, most of the worlds tin comes from Asia, South America, and Australia.

The jump to “engineered” bronze was a step change that involved the reduction of a tin mineral either in situ with copper or in isolation to produce discrete tin. It is thought that polymetallic copper ores were smelted, producing Cu:Sn bronze directly. Eventually, tin ore was identified as a source of smeltable metallic tin.  Why anyone would think to apply reduction conditions to a mineral as seemingly featureless and uninteresting as cassiterite is an intriguing question.

Below is a photo of the result of my first attempt at smelting a cassiterite simulant (SnO2, Aldrich). The SnO2 was treated with carbon black at 900 C for 4 hours in a covered porcelain crucible in a muffle furnace.  After a  failed attempt with a large excess of carbon, the ratio was reversed and heated for a longer period.  For the illustrated sample, the mass ratio of SnO2 to carbon black was ~2:1. All of the carbon black was consumed, leaving a white mass of needles on the granular solids.  Using a USB microscope I searched for evidence of reduction to the metallic state and found numerous examples of sub-millimeter sized pieces of metal.  The yield of metallic tin is estimated at < 1 %.

The purpose of this exercise (for me) is to try gain a better sense of what problems people might have faced smelting tin in antiquity.  Using basic principles, I strongly heated the SnO2 under reducing conditions until the carbon was consumed.  What I did not expect was the large amount of white crystalline material produced. It’s composition is as yet unknown to me.

Next I will make some charcoal or even wood shavings as a reductant for authenticity sake. Who knows, maybe some carbon monoxide generation might be helpful. The muffle furnace does not simulate a reverberatory furnace very well. It could be that gases from a reducing flame are important.

Smelting of Cassiterite Simulant

Early Adventures with Nitrates and Tartaric Acid

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It is a misconception that renaissance alchemists were only concerned with the philosophers stone. Hermetic alchemy was an overlap of alchemical practice within a mystical or spiritual framework. This branch of alchemy and its practitioners are perhaps better known in the popular literature than the alchemists who might be regarded as more pragmatic experimentalists.

Many alchemists over history were very practical and quite occupied with their trade in medicaments, tinctures, distillates, and elixirs or with metallurgical and compounding endeavors.  Paracelsus is regarded as an early practitioner of iatrochemical work, but within a hermetical framework.  Agricola and Biringuccio were 16th century chroniclers of metallurgy that had a basis in earlier alchemical progress.

Consider an entry from a translation of The Laboratory, or School of Arts; in which are faithfully exhibited and fully explain’d, I. A variety of curious and valuable experiments in refining … VI. A dissertation on the nature and growth of saltpeter; … Translated from the German, by Godfrey Smith, published 1738.  In this volume, available from ECCO, Eighteenth Century Collections Online, contains a passage under the heading of “To prepare Aurum Fulmina__s” (two letters obscured). I have retained the archaic character “f” in place of “s” for the reader to enjoy.

To prepare Aurum Fulmina__s

Take Gold that is refin’d with Antimony, beat it to thin Plates, put it into a Phial or Matrafs, pour Aqua Regis upon it, then fet the Phial or Mastrafs upon warm sand, till the Aqua regis is diffolv’d as much of the gold as it is able to contain, which you will knw when you fee the Ebullitions ceafe, pour your Solution by Inclination into another Glafs, and if you fee there remains any Gold in the Matrafs, dissolve it as before with a little frefh Aqua regis, mix your Diffolution, and pour to it five times as much common Water, afterwards drop into this Mixture, by Degrees, the Volatile Spirit of Sal Ammoniac, or Oil of Tartar, and you will see the Gold precipitate to the Bottom of the Glafs, let it reft a good while for the Gold to settle, then pour off the Water by Inclination, wafh your powder with warm Water, till grows infipid, dry it to the Substance of a Pafte, then form it in little round Corns, the Bignefs of a Hempfeed, dry them by the Sun, if you put one of them into a Fire, it will fly and difperfe with a terrible Noife, and beat about with great Violence. [Emphasis mine]

It seems likely that the worker is trying to refine the gold by dissolution of the Sb/Au blend by complete dissolution in aqua regia, followed by what we would now regard as a reduction of the gold solution. Quenching the aqua regia would be expected to cause the gold to reduce and fall out as the native metal. But gold chemistry is not what is interesting in this account.

The Spirit of Sal Ammoniac, meaning either ammonia itself or ammonium chloride, would do as follows: the ammonium would ion pair with nitrate and, upon drying, leave a residue of ammonium nitrate, which is an explosive. Simple open burning of  small kernels material enriched in ammonium nitrate might be expected to deflagrate or pop, as indicated in the end of the description.

The Oil of Tartar, however, might have an altogether different fate when dissolved in aqua regia. Oil of Tartar is a concentrated aqueous solution of potassium (or Na) tartrate.  In solution with aqua regia, one would reasonably expect the two hydroxy groups of tartaric acid to form the dinitro ester if appropriate nitrating species are present. A nitrate ester group is a common explosophore and consists of O2N-O-C comprising an oxygen linkage between NO2 and carbon. This linkage is sensitive to low levels of stimulus, making compounds with such linkages susceptible to rapid or explosive decomposition. The nitrite ester is listed as an explosophore as well.

The nitration of tartaric acid is described in US patent 1,506,728. This patent teaches the use of the standard H2SO4 catalyzed HNO3 nitration of the tartaric acid diol functionality to form a dinitro ester via the standard nitronium ion formation. In the case of aqua regia, the presence of NO2(+) is questionable. Aqua regia is known to produce nitrosyl chloride, ClNO which dissociates to Cl2 and NO.  Literature on the nitration of alcohols to nitro esters in aqua regia is non-existant in Chemical Abstracts. There are a few citations describing aromatic nitration by aqua regia, but no clear description of nitro ester formation.  Indeed, there are many descriptions of direct extraction of gold from aqua regia using isoamyl alcohol with no warnings of explosive or nitro formation.

There are, however, reports of the use of ClNO to produce organonitrites when reacted with a monohydroxy alcohol (Journal of the American Pharmaceutical Association (1912-1977) (1932), 21, 125-8). It is possible that a tartaric nitrite was formed which may be energetic to some extent.

But perhaps the application of Occams Razor is needed. Potassium or sodium tartrate would be mildly basic and upon addition to a mineral acid solution, it would neutralize the acid in sufficient quantities, affording potassium or sodium nitrate (saltpeter). On evaporation of water, the saltpeter residues would be comingled with tartaric acid, comprising a fuel/oxidizer mixture.

Small quantities of crude nitrate esters, nitrite esters, or nitrate salts could have been present in the dried paste, giving the pyrotechnic effect described. The formation of energetic materials was not the primary purpose of the procedure, although the observed behavior of the residues was apparently compelling enough to document.

Vannoccio Biringuccio. Sixteenth Century Chronicler of Metallurgy.

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By the early 16th century in Europe, metallurgy had become an established cottage industry in numerous locales. Artisans were sourcing copper, tin, zinc, antimony and iron ores for reduction, refinement and alloy production for cannon and bells among other products.  While there was no systematic science of chemistry in a form recognizable today, the necessity of constant proportions was understood and exploited to maximize the efficient use of scarce materials. Metallurgists of the 16th century would no doubt share the enthusiasm of developing technology with the same fervor as the technologists of today. 

Unfortunately for these 16th century technologists, the contribution of centuries of alchemy produced a confusing array of occult-based practices. These alchemical practices were based on Aristotelian notions of material “qualities” rather than a system of quantitative relationships of and between substances. It is thought that alchemy began with Grecian metalworker’s practical knowledge of metal preparation. Inevitably, this practical art was overprinted with a thick layer of theological mysticsm by the end of the first millenium. By the end of the alchemical age, any systematic theories of matter were blended into a Mulligan stew of early Roman Catholic mysticism,  incomprehensible nomenclature, and the false choices set forth by Aristotle in his theory of matter.

Fortunately for 16th century practitioners of the metallurgical arts, several encyclopedic works were published detailing the practical art of smelting and casting of metals and what we now know to be alloys.  A prominent early work published in 1540 was the Pirotechnia by Vannoccio Biringuccio (1480-1539). Born in Siena, Italy, over the course of his life Biringuccio traveled extensvely throughout Italy and Germany. His Pirotechnia is a series of books and chapters detailing foundry techniques that he witnessed first hand throughout his travels. He made every attempt to describe methods and techniques in enough detail to accurately capture the technique in question. Above all, he completely drops all the alchemical mysticism and bases his comments on process oriented details such as measured proportions and processing conditions.

Up to this point, what was missing from this very early form of chemistry was a systematic collection of facts and measurements and an accurate chemical model in which to give the facts meaning and predictive value.  Biringuccio, and later Agricola, would begin the disengagement of alchemical mysticism and provide a basis of metallurgical technology upon what might be called science. In a real sense, this helps to set into motion the western industrial revolution. Metallic goods would be produced by very pragmatic artisans who would continue to improve their art through the application of rudimentary measurement.  While it would be four centuries before atomic theory would be developed to make sense of the manner in which definite proportions operated, systematic methods of assay would begin to appear well before atomic theory. The ability to identify value in ores and quantitate it allowed the mass industrialzation of metals.