Okay

so last time we stopped somewhere in the EAF operation.

Oh yeah, right about here.

So I'll just quickly recap TCNA CEAF and then we'll carry on.

So electric arc operation already said that a couple of times

kind of like a big melting machine.

And we unfortunately cannot do as much metallurgy in it as we can do in say a basic oxygen furnace.

But we can run it exclusively on scrap more or less.

And this is the reason why EAFs are becoming so important right now and all of the big industry players are building large EAFs.

Because we want to make green steel and green steel means recycling for now.

Of course

in the long run

we would also like that to be direct reduction from hydrogen based direct reduction from OAS.

But for now

it means we're going to be doing scrap recycling.

And there's two types of EAFs.

And the first type is an ACEAF.

So alternating current

which means you're essentially just taking the electricity from the grid

transforming it to a voltage that suits the electric arc furnace just lower than the grid voltage.

And yeah

and then you run a three phase.

Then you run a three phase electric arc furnace.

So essentially you have electric arcs between the electrodes.

And because it's AC

the electric arc ignites 100 times a second

which puts a lot of wear on the electrodes.

So it's a bit more of a

yeah

we could say discontinuous process

but it's a continuous process with a lot more movement in it than an DCEAF.

So DCEAFs have become has become possible in the last 20 or so years with slow adoption

but still.

And DCEAFs means that I have power electronics that transform my AC from the grid into DC power that I can use in electric arc furnace

which means I get a continuously burning electric arc.

Then single phase.

And I have count electrodes at the bottom of the of the electric arc furnace

which is different to the ACEAF with electric arc burns between the electrodes.

And this is more efficient

a lot less wear on the electrodes

which are pretty expensive.

So the largest consumable apart from the electricity

obviously

in the EAAF are the electrodes and they're very expensive.

Difference again is the appearance of power electronics

especially thyristors that can switch megawatt power.

These are going to be also very

very important for hydrogen based reduction

not because it's in the not because it's in the in the actual furnace.

But once you start building gigawatt level electrolysis