The Mixer

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Note the chalked plate quoting the weight of metal poured

Teeming molten metal from the 400 ton mixer.

 

Pig iron from the blast furnaces was brought to the Bessemer department by rail in 50 ton ladles. The ladle was lifted by a 100 ton overhead crane and poured in to the mixer. The filling spout and lid was offset from the delivery spout and can be seen above and to the left of the stream of iron. 

The mixer stored molten iron, equalling out the composition of the iron. Think of the mixer as a huge refractory lined steel drum that could be rotated about its axis. It had no heat input other than fresh molten iron. Molten iron is being poured out of the mixer into a ladle standing on a weighing machine.

In the foreground are a couple of slag pans (either side) and a couple of scrap kibbles (resembling large sugar scoops with lifting lugs). Leftover slag was dumped in to the pans after each bessemer blow and the kibbles were used to tip scrap steel into the converters to adjust the temperature of each blow.

The mixer was refractory lined, and was subject to wear just like any other such vessel. Running repairs were carried out at weekends when it was almost empty but barely cool enough to allow the bricklayers access. Yes, it is unthinkable in this day and age, but they went inside the vessel when it was still hot - there was no alternative.

Steelmaking required 100 to 150 tons of pig iron every two hours.

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