Does anyone know how iron chloride, magnesium chloride, and copper chloride should be properly disposed.

 

All three are potential products of the metals and hydrochloric acid (1M). After a bit of searching most of the information that I find is the check your state guidelines (CA), but of course I can't find any state guidelines! I'm fairly certain that all three could be disposed of in a typical drain as long as any remaining HCl is neutralized first.

what i did with my copper chloride is put it in a container and slowly let it evaporate and i had these large 2-3" beautiful crystals.

 

i would give that a shot with all of them and if the crystals arent cool or something you want to keep just zip lock bag or other water tight containerthem and throw them away.

 

the slower they evaperate the larger the crystals get

just make sure to dilute them heavily and it'll be fine.