[Gibbon1]

In the 1950's Norway had a pilot plant that made iron by electrowinning sulfide iron ore. Which was a waste product from copper mining. Used a low temperature wet cell. And the steel industry was perfectly happy to take their small production runs.

From memory efficiency was 4.5kwh/kg. At 12 cents/kwh that's $0.50/kg.

Seems like a better idea to do that than to pretend hydrogen is 'green'.

[Hypx]

The amount of hydrogen you need for hydrogen DRI is quite small. From this source: https://www.energy.gov/sites/prod/files/2018/08/f54/fcto-h2-...

You need about 54kg of hydrogen per ton of iron. Assuming it takes 50 kWh of energy to make 1 kg of hydrogen, you get something like 2.7 kWh per kg of iron. This is significantly more energy efficient than the idea you're proposing.

[Gibbon1]

Found this report from a more recent attempt.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6918249/

The Norwegian pilot plant used a crude asbestos separator for the anode and cathode. The above used some magic polymer.

They got it down to 3.53 kwh/kg