![]() The upshot is that Port Talbot Steelworks, with its two massive blast furnaces (the country's biggest), is the single biggest carbon emitter in the country. The reason iron production accounts for such a large proportion of global greenhouse gas emissions (7%, according to the International Energy Agency) - is that we have discovered no better, more efficient way of turning iron ore into pure (or rather purer) iron than deploying carbon, in the form of coking coal.Īt this point, we're probably supposed to start talking about the carbon dioxide being the "waste product" from the blast furnace, but in a sense, carbon is the main product here while steel is the by-product.įor every tonne of steel made here in Port Talbot, about two tonnes of carbon dioxide are pumped into the atmosphere. The coal being emptied into the top of the furnace - and the coal being fired in the side of the furnace in granulated form - is not just there to heat the furnace.Įven more importantly, it is facilitating the critical chemical reaction which turns 60% pure iron into the 95% or so pure iron glugging out of the side of the furnace. Image: Steel rolling at Tata Steel in Port TalbotĪnd there are few other elements in the periodic table which do this job - attracting oxygen atoms and helping purify raw ingredients like iron ore, or for that matter other ores too - as well as carbon. ![]() These furnaces are designed to chemically disassemble the iron oxide in the iron ore, removing the oxygen and any other impurities, and freeing the near-pure metal so it can flow down from the bottom of the furnace. It is tempting to think of a blast furnace as an oven for melting metal, and given the temperature inside gets up above 2,000C (3,632F) - the hottest point was actually 2,237C (4,058F) on the day we visited, which is nearly twice the temperature of lava when it emerges from a volcano - that's understandable.īut it's actually slightly more helpful to think of it as something else: a chemistry vessel. ![]() ![]() The mixture bubbles and melts, then the liquid is tapped for an hour or so, then the clay in the tap wall is remade and the cycle begins again. In it all goes, layer upon layer, night and day. The coal - or rather coke, a form of heated, near-pure carbon - being emptied into the top of the blast furnace today is a mixture of the stuff they roast in the ovens on site here in Wales, as well as varieties from elsewhere around the world. Image: Steel coking at Tata Steel, Port Talbot Is there any other contraption that better exemplifies humankind's determination to harness the elements and transform the world? The room is bathed in a red glow and the temperature is rising.īlast furnaces are extraordinary things. Then the smoke clears and suddenly we see it: a stream of yellow-hot liquid metal, lava, pouring along a channel in the floor beneath us. ![]() We are all wearing flame-retardant protective clothing and it is just as well because for a moment the fireworks threaten to engulf us. Suddenly, the side of the furnace is wreathed in black smoke and then it begins - a firework display of yellow sparks shooting out as the iron begins to escape. Then the drill penetrates the wall and there is a roar as it bores through the clay. Even before the point of the drill makes contact, the side of the blast furnace is burning hot.įlames of gas escape from cracks in the side, like an enormous kitchen hob. Only a few metres away behind the refractory lining of the oven, is a bubbling reservoir of, for want of a better word, lava.Īs we watch, an enormous drill on a robotic arm swings across towards the base of the blast furnace and the "tap wall" near its bottom. Inside the cast house floor, the air is thick with the acrid smell of sulphur and soot. ![]()
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