If you only need it for testing for metals as their sulfides, thioacetamide (if you can find it) also works well.testimento - 24-7-2013 at 16:04
The carbon reduction of sodium sulfate with carbon requires a high temperature, even up to 900C as per the sodium sulfate melting point, but the
method is used in industrial setups with large scale of different sulfates and it works, aside from roasting with hot air to directly dislodge the
sulfur dioxide, usually for sulfuric acid prouction scheme. 900C can be reached with ceramic crucible and propane torch using heat shields, but a lot
easier way is to use nichrome wire around the crucible with dimmer. Remember to vent the carbon monoxide safely away if you ever procceed to attempt
the process.subsecret - 24-7-2013 at 16:28
Are there any reducing agents that would make the reaction easier to initiate?gdflp - 21-2-2014 at 11:14
I know this is an old thread, but heating a solution of sodium hydroxide and adding sulfur powder till no more dissolves, then chilling in the freezer
to crystallize out the sodium thiosulfate will make sodium sulfide usable for your purposes.Zyklon-A - 21-2-2014 at 12:10
The sodium sulfide wont be anhydrous, though. And it's impossible to separate the hydrates.gdflp - 21-2-2014 at 13:06
It doesn't need to be anhydrous for lead testing. Zyklon-A - 21-2-2014 at 13:15