# When recovering Copper from Copper Chloride via Aluminum, why can't we use Sodium instead to make Sodium Chloride?

About a week ago in my Middle School Science Class, we used an aluminum washer and some copper chloride, which we had gotten from creating circuit boards, in a closed system to recover the copper (if it was possible). We resulted in getting some copper flakes, but as a consequence the copper was replaced by aluminum in the chloride solution. So technically it is still a waste material that can't be used in everyday life, despite having recovered the copper.

So I got thinking: If Salt, or Sodium Chloride, is Sodium and Chlorine, and is much more useful than Aluminum Chloride or Copper Chloride since we need it in our everyday diets, what prevents us from using it to recover copper from chlorine?

I asked my teacher what she thought about the subject, and she explained that apparently sodium is very reactive when not bonded to anything and so is hard to come by naturally without extracting it from something else. I gathered that Aluminum, as reactive as it is, is apparently more common to find, or cheaper to manufacture, than sodium is. This was an unsure answer, as the costs and waste produced when manufacturing aluminum vs. manufacturing sodium were not looked up or explained.

However, in an earlier lesson we had learned that manufacturing aluminum produces a lot of hazardous waste, and so does not have a great impact on the environment to make. I do not know about sodium and its costs and waste production.

With that information provided, and a consideration of the environment at hand, would it be better to consistently use sodium in the recovery of copper from copper chloride than aluminum? Consider all waste produced from manufacturing and all costs to create when answering, please.

Thank you.

• Welcome to Chemistry! Take the tour to get familiar with this site. Mathematical expressions and equations can be formatted using $\LaTeX$ syntax. If you receive useful answers, consider accepting one. – pentavalentcarbon May 22 '17 at 23:36
• Go ahead, try it. All you have to do is obtain some metallic sodium, then when you add it to the water avoid side reactions with the water that will consume the sodium ... and possibly ignite. Can you use magnesium, maybe? – Oscar Lanzi May 23 '17 at 0:42

## 1 Answer

As your teacher mentioned, sodium is a very reactive material. She mentioned that it is hard to obtain it naturally as a result. However, this isn't quite the reason as to why sodium isn't used for recovery.

If we were to only consider the cost in energy, aluminum would be a poor choice. The main process for production of aluminum metal requires a current of 400 kiloamperes and temperatures of 950 C. In contrast, the main process for sodium metal production requires a current of 30 kiloamperes and temperatures of 600 C.

The main reason would be because sodium is too reactive to be used. The sodium metal would react with the water and form sodium hydroxide. This reaction would be too fast and violent that you wouldn't be able to recover copper. So your teacher was right in pointing out that sodium is too reactive.

• What if the water was evaporated away so there was just solid CuCl? Water will evaporate at a much lower point than the melting point of Copper Chloride, and I would think it would be possible to boil it off. Would there be a problem in using sodium then? – Pyram Linum May 24 '17 at 2:22
• Check that - The CuCl was brought to its melting point in addition, to make it a liquid. – Pyram Linum May 24 '17 at 2:40
• @PyramLinum I am not sure. However, at that point there's too much waste. I think that if your overall goal was to reclaim copper, you would be better off doing an electrolysis on the copper chloride: docbrown.info/page01/ExIndChem/electrochemistry06.htm That way, you obtain chlorine, which has industrial uses, and the desired copper. – CoffeeIsLife May 24 '17 at 3:06
• Alright, I guess that works. Thank you for helping me understand this. – Pyram Linum May 25 '17 at 4:19