The copper I purchased ended up being much more coarse than I expected. The reason that I wanted very fine copper shavings was to further enable oxidation when I mixed the metal into concrete as part of the aggregate. Not having a Blendtec blender to destroy with copper (Blendtecs are famous for blending iphones, ipads, etc into a fine dust) I decided not to try making the copper shavings finer.
Instead I decided to begin oxidizing the copper before mixing it into concrete. I used a similar method to my last accelerated weathering experiment.
About the Solution
Combining vinegar and hydrogen peroxide creates Peracetic Acid which is highly corrosive. It is also very dangerous and exposure can cause “irritation to the skin, eyes and respiratory system and higher or long-term exposure can cause permanent lung damage”. Do not attempt creating this solution unless you hold a degree in chemistry.
- 2 oz white vinegar
- 10 oz hydrogen peroxide
- 2 tb salt
- 1 glass bottle
- coffee filters
- funnel all of the copper into a clean glass bottle.
- fill bottle with vinegar and shake. this will remove any oil or grease on the metal.
- poke pin holes in all of your coffee filters
- drain the vinegar from the container using coffee filters to catch the copper
- add salt to container, then vinegar, then hydrogen peroxide
- close container and shake
- remove container lid
- allow to sit for a little while (20 – 30 minutes)
- drain the paracetic acid solution from the container using coffee filters to catch the copper
- fill container with water and drain. repeat this until the water becomes somewhat clear.
I had to use apple cider vinegar because the store I went to was all out of white vinegar. I hate apple cider vinegar. It is the worst smelling substance on the face of the planet.
After a few minutes the paracetic acid will turn bright green. I noticed while shaking the container that a considerable amount of pressure was building inside the bottle and that the reaction inside was generating considerable amounts of heat. Not wanting the bottle to explode in my face, giving me acid burns, I carefully removed the cap to release the pressure. Foam bubbled up out of the bottle. The solution was bright green.
The copper did oxidize a little bit. It lost most of its sheen and became a dull brown. In some places the copper did become green.