Potassium Nitrate is an ingredient in making fuses, among other things. Here is how you make it:
-3.5 gallons of nitrate bearing earth or other material
-1/2 cup of wood ashes
-Bucket or other similar container about 4-5 gallons in volume
-2 pieces of finely woven cloth, each a bit bigger than the bottom of the bucket
-Shallow dish or pan at least as large in diameter as the bucket
-Shallow, heat resistant container
-2 gallons of water
-Something to punch holes in the bottom of the bucket
-1 gallon of any type of alcohol
-A heat source
-Paper & tape
- Punch holes on the inside bottom of the bucket, so that the metal is"puckered" outward from the bottom
- Spread cloth over the holes from the bottom
- Place wood ashes on the cloth. Spread it out so that it covers the entire cloth and has about the same thickness.
- Place 2nd cloth on top of the wood ashes
- Place the dirt or other material in the bucket
- Place the bucket over the shallow container. NOTE: It may need support on the bottom so that the holes on the bottom are not blocked.
- Boil water and pour it over the earth very slowly. Do NOT pour it all at once, as this will clog the filter on the bottom.
- Allow water to run through holes into the shallow dish on the bottom.
- Be sure that the water goes through ALL of the earth!
- Allow water in dish to cool for an hour or so
- Carefully drain the liquid in the dish away, and discard the sludge in the bottom
- Boil this liquid over a fire for at least two hours. Small grains of salt will form - scoop these out with the paper as they form
- When the liquid has boiled down to 1/2 its original volume let it sit
- After 1/2 hour, add equal volume of the alcohol; when this mixture is poured through paper, small white crystals appear. This is the posassium nitrate.
- Redissolve crystals in small amount of boiling water
- Remove any crystals that appear
- Pour through improvised filter then heat concentrated solution to dryness.
- Spread out crystals and allow to dry