+VLFBERH+T, Bog Iron, & a Metallurgical Mystery

Nov 20, 2022

Steel is Civilization's most useful metal. One of the most interesting steel stories involves the origin of an apparently related brand of Northern European swords bearing a Frankish personal name that amounts to Wolf + Bright or Bright-Hunter.

We’ve managed to collect some 170 examples of Wolf-Bright swords. Dating from 800 to 1,000 A.D., the mystery of their metallurgy has yet to be proven. The steel is unlike any other steel items from medieval Europe and was nor replicated for 1,000 years. It was nothing like the Bog Iron available to Northern Europeans.

The secret to steel is not iron, but carbon. Controlling its precise content makes all the difference between steel that’s either too soft or too brittle. The carbon content in the Ulfberht steel is about three times higher than that of other swords of its time, making it both stronger and more flexible than other swords. The steel had almost no impurities (slag), a necessary requirement for the even distribution of carbon.

To reach such high purity, iron ore must be heated to 3,000 degrees Fahrenheit, a feat the Ulfberht makers apparently accomplished 800 years ahead of their time. Prior to the discovery of the sword’s metallurgy, it was believed that such purity was only possible after the Industrial Revolution. In this 2017 episode of NOVA, a blacksmith delves into some of the mysteries of the Wolf-Bright sword.

Steel is the most important metal for modern Civilization. Consider the scale that we consume new iron ore compared to all other metals combined. But the biggest impact from steel production is not limited to mining and refining iron ore, but also from the equally huge volume of metallurgical coal (coke) required to make steel.

Coke (Not the Cola Kind)

The essential reaction is Fe2O3 + 3CO -> 2Fe + 3CO2. Worldwide, the primary agent for this reaction is coal that has been purified to make it dry—much the same way that hardwood is converted into charcoal. The light oils and gasses must be removed first, leaving dry, high-carbon, almost smoke-free carbon.

In 1946, after serving on the USS Utah and USS Honolulu during the Second World War, my grandfather went to Butte, Montana to carry my mother (whom he had just met), his wife (and her mother and brother) back to his home, Orem, Utah. His first job was at Geneva Steel.

All the stacks in the background - those are the coke ovens. That's where he first started working, making coke. He made $0.75 per hour, the highest wage he'd ever been paid. His son, Terry, also started working at Geneva making coke in the 1960s, right after high school. It was a nasty, hot, and dangerous job.

H2 and the Direct Reduction of Iron Ore

But coke and coal are not required to make steel. One of the most promising applications of Nuclear Power is the Direct Reduction of iron ore via H2 that can be very efficiently produced through high-temperature processes and consumed onsite.

The potential for high temperature nuclear to replace industrial combustion heat source is overdue. As my article details, such a reactor design could in principle slot into the DRI process. Indeed, as a cogen plant it could supply all of a modern steel mill's energy.

Oscar Archer

Nuclear Power also gives rise to many other promising industrial applications, all of which rely on carbon-based fuels and feedstocks today.

But just limiting the scope of this analysis to steel, one of the most promising things about Direct Reduction of iron ore via Nuclear Power is that the H2 is consumed onsite. In other contexts, such as for transportation fuel, H2 has significant limitations, such as the embrittlement of steel and other materials and the difficulty of compressing and transporting it. But in a steel mill, all the H2 would be consumed on site and these limitations would not be a problem. Imagine being able to make much of the worlds steel without coke.

But the benefits do not end with the steel. The efficient, high-temperature electrolysis of water into H2 also yields an equal amount of O2 as a byproduct. Large volumes of low-cost, pure O2 present significant industrial opportunities. For one thing, unlike H2, O2 can be safely and cost-effectively compressed, stored, and transported. But why does abundant O2 matter? Simple. Oxy-fuel Combustion

Combustion with O2 is significantly more efficient than atmospheric combustion. Much more heat. Less pollution - N2 combustion is avoided and associated air pollutants. The mass and volume of the flue gas, and the equipment for flue gas treatment, are reduced by some 75%. The flu gas produces clean, pure CO2 that is easy to manage, such as in the creation of--brace for it: Synfuels!

Not Your Father’s Nuclear Power Plant

When it comes to Nuclear Power, we are limited by our own minds. Most everybody on the planet thinks of Steam making Electricity.

But this is the lowest use of nuclear power’s thermal energy. Before 1921, Rudolph Diesel’s engine had been limited to a stationary, workhorse engine solely for industrial applications. By 1921, however, some industrious people had a new idea: Daimler-Benz and Mercedes-Benz, developed a twin cylinder diesel engine for trucks in 1921 and also used it in the Benz-Sendling three-wheeled motor plough in 1923.

It may look simple but it is not. This little invention is the direct ancestor of every diesel machine in the world today. Every farm tractor of every configuration; every piece of construction equipment; every piece of mine equipment; every long-haul truck; every locomotive engine. None of these would exist today had it not been for a few engineers thinking about ways to apply a very efficient engine with an immediate need for efficient Work.

The time has come for us to stop thinking about the Nuclear Power Plant the same way people saw Rudolph Diesel’s stationary engine and start thinking of better ways to use the vast thermal energy generated when we split atoms instead of mining them. Now this is not to say I am advocating for mobile nuclear reactors; however, the idea may not prove to be quite so far-fetched as we may imagine.