Zapping red mud for fun and profit:

[Subduction Zone]

https://www.science.org/content/article/zapping-red-mud-plasma-turns-mine-waste-valuable-iron?utm_source=sfmc&utm_medium=email&utm_content=alert&utm_campaign=WeeklyLatestNews&et_rid=40989465&et_cid=5076641

"Red mud" is a by product of bauxite (Al2O3) mining. It is a mixture of iron, other rare earths and is extremely alkaline. It is usually just left in large pools because it is expensive to process. Now a way has been found to possibly make money from it. The mud is heated in the presence of a hydrogen plasma and it smelts the material leaving balls of iron behind. Even better, the highly alkaline mud is now neutral and can be used for making concrete and other products.

"Over the years, mining for aluminum has left behind billions of tons of the caustic sludge called red mud. But today in Nature, scientists report that a simple chemical process can extract another useful metal, iron, from this waste and render the remainder into a mostly benign substance useful for making concrete. If the process can be scaled up and proves cost-effective, it could help manufacturers convert waste into climate-friendlier steel, the researchers say.

“Very promising,” is how Yiannis Pontikes, a mechanical engineer at KU Leuven, describes the speed of the reactions and the purity of the product. But Pontikes, who was not involved in the research, cautions that the experiment was done on just one type of red mud, so it’s hard to generalize about its utility.

The first step in making aluminum is to mine a rock called bauxite, which is rich in aluminum oxide, also known as alumina. Extracting the alumina leaves behind waste called red mud that is highly alkaline and can also contain toxic heavy metals such as cadmium. Every year this process generates about 180 million tons of red mud. The stuff is left in reservoirs to dry, and dam breaks have unleashed devastating floods. Currently, only a tiny amount of the waste is treated to make it less caustic. After it’s been made harmless, the leftover substance can be used as fill-in construction material."

An interesting read and some possible good news for the environment.

 

[Heyo]

@Subduction Zone: you should disable "RF mode" from your autocorrect when posting secular OPs.

 

[Subduction Zone]

@Subduction Zone: you should disable "RF mode" from your autocorrect when posting secular OPs.

I sent in a request to change the title minutes after making it when I saw it. But to no avail.

 

[Revoltingest]

So who's the prophet?

 

[JustGeorge]

I sent in a request to change the title minutes after making it when I saw it. But to no avail.

Fixed it for you.

(Though I enjoyed that typo...)

 

[Subduction Zone]

Fixed it for you.

(Though I enjoyed that typo...)

Thank you. My mind was in RF mode when I wrote the title, I realized that as soon as I saw my title and another Heyo pointed that out here as well.

 

[exchemist]

https://www.science.org/content/article/zapping-red-mud-plasma-turns-mine-waste-valuable-iron?utm_source=sfmc&utm_medium=email&utm_content=alert&utm_campaign=WeeklyLatestNews&et_rid=40989465&et_cid=5076641

"Red mud" is a by product of bauxite (Al2O3) mining. It is a mixture of iron, other rare earths and is extremely alkaline. It is usually just left in large pools because it is expensive to process. Now a way has been found to possibly make money from it. The mud is heated in the presence of a hydrogen plasma and it smelts the material leaving balls of iron behind. Even better, the highly alkaline mud is now neutral and can be used for making concrete and other products.

"Over the years, mining for aluminum has left behind billions of tons of the caustic sludge called red mud. But today in Nature, scientists report that a simple chemical process can extract another useful metal, iron, from this waste and render the remainder into a mostly benign substance useful for making concrete. If the process can be scaled up and proves cost-effective, it could help manufacturers convert waste into climate-friendlier steel, the researchers say.

“Very promising,” is how Yiannis Pontikes, a mechanical engineer at KU Leuven, describes the speed of the reactions and the purity of the product. But Pontikes, who was not involved in the research, cautions that the experiment was done on just one type of red mud, so it’s hard to generalize about its utility.

The first step in making aluminum is to mine a rock called bauxite, which is rich in aluminum oxide, also known as alumina. Extracting the alumina leaves behind waste called red mud that is highly alkaline and can also contain toxic heavy metals such as cadmium. Every year this process generates about 180 million tons of red mud. The stuff is left in reservoirs to dry, and dam breaks have unleashed devastating floods. Currently, only a tiny amount of the waste is treated to make it less caustic. After it’s been made harmless, the leftover substance can be used as fill-in construction material."

An interesting read and some possible good news for the environment.

From the article it seems the plasma is a source of both H+ i.e. acid, capable of transforming OH- to H2O and free electrons, capable of reducing Fe2+ and Fe3+ to metallic iron.

I imagine the key to this, commercially, will be the input energy required to supply the Ar/H plasma. And you need hydrogen of course, which requires yet more energy to produce, from electrolysis of water if it is to be done in a carbon neutral way.

So many processes proposed for a greener future require hydrogen, yet we still do not have an efficient way to split water. Cracking this nut will be key for the future, it seems to me.

 

[Subduction Zone]

From the article it seems the plasma is a source of both H+ i.e. acid, capable of transforming OH- to H2O and free electrons, capable of reducing Fe2+ and Fe3+ to metallic iron.

I imagine the key to this, commercially, will be the input energy required to supply the Ar/H plasma. And you need hydrogen of course, which requires yet more energy to produce, from electrolysis of water if it is to be done in a carbon neutral way.

So many processes proposed for a greener future require hydrogen, yet we still do not have an efficient way to split water. Cracking this nut will be key for the future, it seems to me.

Thanks for the input. I have no idea how hard it would be to generate a hydrogen plasma or what the energy requirements would be compared to the normal coke and iron ore smelting process. Of course coke and iron ore adds large amounts of CO2 to the atmosphere. If there was a large supply of cheap green electricity this would be a win win.

A quick check and China is by far the king of aluminum smelting right now. I have a feeling that making a profit is their main drive these days so I am not holding my breath on this technology.