Synthetic iron oxides are made using a few different methods, primarily thermal decomposition, precipitation, and the reduction of organic compounds by iron.
Methods for Producing Synthetic Iron Oxides
| Method | Description | Colors Produced |
|---|---|---|
| Thermal Decomposition | Involves heating iron salts, such as ferrous sulfate, to high temperatures. | Primarily reds |
| Precipitation | A chemical process, such as the Penniman-Zoph process, where iron compounds are precipitated out of a solution. | Yellows, reds, browns, and blacks |
| Reduction of Organics | Iron reduces organic compounds; for example, nitrobenzene is reduced to aniline in this process. | Various, depending on the process |
Thermal Decomposition
- This method typically involves the breakdown of iron salts at high temperatures.
- Example: Heating ferrous sulfate to produce red iron oxide pigments.
Precipitation
- This process involves forming solid iron oxide particles from a solution.
- Example: The Penniman-Zoph process, which can be used to produce a variety of colors including yellows, reds, browns, and blacks.
Reduction of Organic Compounds by Iron
- In this method, iron is used to reduce organic compounds.
- Example: The reduction of nitrobenzene to aniline, where iron oxide is a byproduct.
