Iron is a lustrous gray metal and the fourth most abundant element in the Earth’s crust. While exceedingly rare in pure metallic form, iron is prodigiously abundant as an ore called Magnetite (Fe3O4). The exploration and mining of iron ore, and the manufacture of iron-based products, such as high-strength steel, are crucial to countries undergoing industrialization. The metal, quite literally, forms the skeleton of modern infrastructure. The word iron lent its name to the “Iron Age” and while it is true that today humanity mines more sophisticated metals, such as titanium, tungsten and aluminum, we are still, in many important ways, living in the age of iron.
Humanity has collected, mined and processed iron ore into metallic iron since approximately 1200 BCE. However, it took another 700 – 1,000 years for iron to gain sustained production momentum through much of Europe and Asia. The relatively slow utilization of iron was largely due to technical difficulties associated with our primitive exploration, mining and smelting processes. The earliest uses for iron were largely ornamental, gradually evolving in size and complexity into larger tools and weapons. From the 12th century through the onset of the Industrial Revolution, iron was produced in modest quantities and to poor quality standards.
From 1750 or the inception of the Industrial Revolution, iron production in Europe underwent a series of technological advances. For example, the Bessemer Steel Process, patented by the British inventor Sir Henry Bessemer in 1857, injected oxygen into molten iron, burning off impurities. That allowed humanity to produce strong, durable steel on an industrial scale for the first time. (Steel is an alloy of iron and carbon, and sometimes other elements, known for its strength.) The industrial smelting of iron into steel made possible the production of larger and stronger tools, which in turn helped to build the literal and figurative engines of industrialized progress.
Scaling up of iron production in Great Britain, the birthplace of the Industrial Revolution, led to a dramatic increase in the demand for wood. That happened, because charcoal - a porous black solid that is obtained as a residue when wood is heated in the absence of air - was the primary smelting fuel of early iron production. Charcoal production grew at such an enormous rate so as to create significant deforestation pressure across Britain. At that time, the annual production and forging of some 17,000 metric tons of British iron required an astonishing 830,000 metric tons of charcoaling wood. That equals to a destruction of 1,700 square kilometers (656 square miles) of forest annually.
Both historical and modern production of iron and steel is energy intensive across all parts of the mining, smelting and forging processes. The introduction of coal as the primary energy source of the Industrial Revolution quite literally saved the forests of Britain and many other regions from being entirely destroyed. Over time, advances in technology have resulted in iron and steel production processes that yield far superior products with a dramatically reduced energy input. As Vaclav Smil, one of the preeminent energy thinkers today noted in his 2016 book Still the Iron Age: Iron and Steel in the Modern World, “The history of ironmaking can be seen as a continuing quest for higher energy efficiency, and this brought typical fuel requirements from almost 200Gj/t of pig iron in 1800 to less than 100Gj/t by 1850, to only about 50Gj/t by 1900, and less than 20Gj/t a century later.”
It is a testament to human ingenuity that we now produce iron and derivative products like steel at greater volumes and better quality than ever before. And we do so both at a lower cost to ourselves - the producers - and the environment. The global production of finished iron has grown from approximately 800,000 metric tons globally in 1750, to over 1.8 billion metric tons in 2018. In 2018, China alone produced more refined steel annually than all of human civilization did in 1750. Put another way, modern global steel production is over 2,200 times greater than the steel production at the dawn of the Industrial Revolution.
As Smil noted, modern civilization is more dependent on iron exploration, mining and steel production than at any other point in human history. From vehicle production and concrete reinforcement bars (also known as rebar), to stainless steel medical tools and home cookware, iron is embedded in many tens of millions of everyday items. About 54 percent of all finished steel is used in construction and infrastructure. The remainder of the steel produced provides every manner of convenience and luxury. At any given moment, more than 50,000 steel merchant container ships are moving more than 13 million standardized steel containers across the world’s oceans. That amounts to 90 percent of the world’s trade, helping to foster progress, growth and improving living standards.
The good news is that we haven’t finished improving the exploration and production of iron. Nor have we exhausted the scope of iron’s application. As Bill Gates commented in his August 27th 2019 Gates Notes, “Whenever I hear an idea for what we can do to keep global warming in check—whether it’s over a conference table or a cheeseburger—I always ask this question: ‘What’s your plan for steel?’” Today Boston Metal, an American company, is working on manufacturing steel with little or no greenhouse gas emissions. Hundreds of other businesses push the boundaries of what is possible. If you want to learn more about iron exploration, production and history, the author recommends a 2016 book titled Still the Iron Age: Iron and Steel in the Modern World by Vaclav Smil, Distinguished Professor Emeritus in the Faculty of Environment at the University of Manitoba in Winnipeg, Canada.
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