Ceramic raschig rings are a highly effective and low-cost material to pack your reflux column with. We typically recommend that people use 1 pound of copper mesh and 1 liter of ceramic raschig rings to pack our 2-inch still column extender or 3-inch reflux column. The copper helps remove the sulfides, and the raschig rings are much cheaper on a per volume basis and will last forever. For more information on copper mesh vs. ceramic raschig rings, we have a post about column packing or a video on different types of still column packing on our blog with all you need to know.
These raschig rings should last a lifetime, as long you don’t lose them! Since they are ceramic and porous, after several runs they will begin to absorb some of the undesired compounds that you are trying to strip out with your reflux still. If you wish to clean them, you can easily do so by spreading them out on a cookie tray and baking them in any household oven. The heat should vaporize any remaining volatile compounds and leave you with clean raschig rings.
If you are distilling ethanol for fuel or water to remove flavors (like pond water), you can use 100% ceramic raschig rings without copper mesh, since you won’t need to worry about removing the traces of sulfides.