Hydrogen reduction in molten copper

Meet Gunnar Hovestadt! He is a Ph.D. student at RWTH Aachen and is dealing with hydrogen reduction in molten state. He is part of the copper reduction team and supervises several student thesis in our project.

With his Ph.D. topic Gunnar wants to develop new reduction processes with hydrogen to reduce metal industries CO₂ footprint. In some processes hydrogen could have several advantages regarding kinetics and selectivity. Hopefully those techniques will be applied in industry soon.

In small scale the security clothing could be made of cotton and special heat resistant fibres. In large scale the clothing gets a metal vapour-plated surface to get radial heat protection. It is very hot inside those clothes!

Update from the lab!

Here is how a real bigger setup looks like. This is from installation of the gas analyser to detect unreacted H₂. Hydrogen gas will self-ignite above 560°C if oxygen is present. Controlling the low oxygen and unreacted H₂ content is therefore essential in larger scale.

Hydrogen gas will self-ignite above 560°C if oxygen is present. Controlling the low oxygen and un-reacted H₂ content is therefore essential in larger scale.

Scientist at RWTH Aachen University is handling a crucible containing liquid copper slag. Heat shield and thermal protective clothes and gloves are used. The melt is around 1300 °C. Do not touch the crucible.
Photo: Tom Gertjegerdes

After the tests where hydrogen gas is added to liquid copper slag, it’s time to cast. We are looking forward to analysing all the samples we’ve made. By these experiments we have started investigating the fundamental problems to be overcome when using hydrogen gas to recover copper from slag. Now we need to look further into the chemistry of the reduction process.