# Sulfates and persulfates as accelerants in black powder?

I saw there was a few black powder posts on here so I'd like to pose a question. Would sulfates or persulfates like the oxidixer soduim persulfate be a good replacement for some percentage of the nitrates or usual sulfer content of black powder? Pursulfates are used as an ingredient in flash powder for pyrotechnics and is a strong oxidizer to combustibles, so I assume it would make a good accelerant in some concentration. Would it perform under the pressures and speeds needed for an old fashioned firearm, or would it be too corrosive to be practically used?

Sulphates and persulphates cannot be considered as analogues to chlorates and perchlorates.

• Perchlorates are frequently used in professional pyrotechnics, being more reactive than nitrates.
• Chlorates are too reactive for safe use.
• Sulphates are useless as not acting as oxidant.
• Persulphates have limited oxidative oxygen content, compared to nitrates or perchlorates, but as chlorates are too reactive for safe operations.

As a general rule, you must know what you are doing. More reactive mixtures may not only lead to faster wearing of the guns, but also to a gun blowing into your face.

Sulphur cannot be replaced by sulphates/persulphates, as it has the opposite role than oxidants. It would be like if you wanted to replace oxygen for breathing by carbon dioxide, as both contain oxygen.

Gun powder

Chemical reaction

Gunpowder does not burn as a single reaction, so the byproducts are not easily predicted. One study showed that it produced (in order of descending quantities) 55.91% solid products: potassium carbonate, potassium sulfate, potassium sulfide, sulfur, potassium nitrate, potassium thiocyanate, carbon, ammonium carbonate and 42.98% gaseous products: carbon dioxide, nitrogen, carbon monoxide, hydrogen sulfide, hydrogen, methane, 1.11% water.

However, simplified equations have been cited.

A simple, commonly cited, chemical equation for the combustion of black powder is $$\ce{2 KNO3 + S + 3 C -> +K2S + N2 + 3 CO2}$$

A balanced, but still simplified, equation is $$\ce{10 KNO3 + 3 S + 8 C -> 2 K2CO3 + 3 K2SO4 + 6 CO2 + 5N2}$$

• Black powder is a mixture of three substances : saltpeter $\ce{KNO_3}$, sulfur and charcoal. The reaction taking place with black powder is :$$\ce{2 KNO_3 + 3 C + S -> K_2S + N_2 + 3 CO_2}$$ It is a rather strange reaction, because two substances are acting as oxidant : Nitrogen from $\ce{KNO_3}$ and Sulfur. These two atoms are reduced, Sulfur from $0$ to $-2$, and Nitrogen from $+5$ to $0$. The only element that is oxidized is Carbon. It also should be mentioned that as soon as $\ce{K_2S}$ is produced, it gets oxidized by $\ce{O_2}$ from the air into $\ce{K_2SO_4}$. – Maurice Apr 19 '20 at 16:06
• by nitrate as well. As there is not the only one equation describing the gunpowder burn. – Poutnik Apr 19 '20 at 16:08
• Your general comment on persulfates is not likely accurate, in fact, with ammonium persulfate, it may be potentially a very dangerous energetic. See my answer and reference below. – AJKOER Apr 20 '20 at 0:20
• I have written about available oxygen. – Poutnik Apr 20 '20 at 3:39

Per the Energetic Materials Section in ScienceMadness to quote:

anyone got anything on any high energy fuels for a high explosive flash powder? I know that ammonium persulfate and ferrocerium can be very explosive, and...

Here is a link to Ferrocerium for those interested.

So, please avoid the use of ammonium persulfate in select mixtures due to possible problematic/dangerous energetics per my readings (sorry no personal experience here).