I am producing Iron Oxide with the intention of using it for pigmentation. My attempts so far have been to use electrolysis. My first attempt I used Borax as an electrolyte and a 12 volt adapter with 3-4ish amps. The result was a typical light orange rust color, however the process was rather slow, 24 hours resulted in about a tablespoon of rust. My next attempt I used table salt instead. This was far faster, it produced nearly a cup of black sludge in 10 hours. As per the tutorials I watched on youtube, I then filtered the matter through a coffee filter and a funnel, then heated the result in a pan. The result however was a rust color covered in a layer of black crust, as if I had burnt a sheet of cookies. Powdering the result gave me a powder of very dark brown color.The Residue left over on the coffee filter and in the container I used for electrolysis are the typical rust orange color I would expect. It is my understanding that heating the black matter that results from the electrolisis usually produces a more red color. So my question(s) are:
- how I can change my approach to produce red pigmentation using this process, and why may I have ended up with black residue instead of orange or red?
- What are the variables that change the pigmentation of rust?
- Is it the speed at which it drys? the temperature in which it is heated? the electrolyte used in the process of electrolysis?