Jump to content
APC Forum

Black Powder and nitrates


Recommended Posts

Posted

Does anybody here know why sodium or potassium nitrate can be used to make black powder, but strontium or barium not?

Posted

I mean they can be used. They tend to be more sluggish of oxidizers than potassium or sodium nitrate, in addition to being more expensive. A modification in ratios may be required due to the heavier metals. If you're trying to get colors out of them, that is unlikely to work. That much charcoal has a tendency to turn everything orange.

Posted

Black Powder developed before exotic nitrates were easily and cheaply available. Sodium nitrate and some others will not make good powder because it absorbs water too easily (BP was used in the early ships guns.)

 

After that BP with or without sulphur has been used in a formulation approaching the modern formula for so many years that it is the base for many formulations and calculations.

 

A good reliable source of BP is a pyrotechnist's best asset.

Posted

I was asking because I was curious about what decides how particular nitrate will react. Ammonium nitrate has different decomposition path so it affects how it reacts. Obvious to me is that sodium and potassium are alkali metals and calcium, strontium and barium are alkaline earth metals. Because of the different valency of alkaline earth metals there is not a big difference in the amount of available oxygen per unit of weight - for example potassium and strontium are very close...

I do not expect to get colors from different types of BP except sodium - burns nice warm yellow. Maybe lithium could work but I do not have it to test it...

My chinese thermometer/humidity meter shows values from 20-30% relative here where I work with pyro stuff and it may not be precise but it sems to be right. I can wet my sodium BP and it becomes dry overnight. When heated it loses only few percent of its weight, so it is almost dry.

Posted (edited)

Sodium nitrate based ( "B" blasting powders ). Were often used where more of a pushing/heaving force was needed.

 

Sodium nitrate based comps can be water bound. Up to about a RH of 60%. It's actually a little higher than that 64/66% iirc. I would need to look it up though, to be specific.

Edited by Carbon796
×
×
  • Create New...