Double Salts is used as a primary explosive in the fabrication of detonators (Section VI, No. 13). It can be made in the field from silver (coins), nitric acid, calcium carbide, and water.
MATERIALS REQUIRED:
- Nitric acid (90% conc.) (Section I, No. 4)
- Silver metal (silver coin, about 5/8 in diameter)
- Calcium carbide (acetylene or calcium carbide lamps)
- Rubber and glass tubing (approx. 1/4 in. inside diameter)
- Paper towels
- Heat-resistant bottles or ceramic jugs, 1 to 2 quart capacity, and one cork to fit. (Punch hole in cork to fit tubing.)
- Teaspoon (aluminum, stainless steel or wax-coated) or equivalent measure
- Glass container
- Heat source
- Long narrow jar (olive jar)
- Tape
- Water
- Alcohol
PROCEDURE:
1. Dilute 2-1/4 teaspoons of nitric acid with 1-1/2 teaspoons of water in a glass container by adding the acid to the water.
2. Dissolve a silver coin (a silver dime) in the diluted nitric acid. The solution will turn to a green color.
NOTE: It may be necessary to warm the container to completely dissolve the silver coin.
CAUTION: Acid will burn skin and destroy clothing. If any is spilled, wash it away with a large quantity of water. Do not inhale fumes.
3. Pour solution into a long narrow (olive) jar and place it in a bottle of hot water. Crystals will form in the solution; heat until crystals dissolve.
4. While still heating and after crystals have dissolved, place 10 teaspoons of calcium carbide in another glass bottle and add 1 teaspoon of water. After the reaction has started add another teaspoon of water.Then set up as shown.
5. Bubble acetylene through the solution for 5 to 8 minutes. A brown vapor will be given off and white flakes will appear in the silver solution.
6. Remove the silver solution from the heat source and allow it to cool. Filter the solution through a paper towel into a glass container. Green crystals will collect on the paper.
7. Wash the solids collected on the paper towel with 12 teaspoons of alcohol. The solid material will turn white while the solvent in the container will have a green color.
8. Place the white solid material on a clean paper towel to air dry.
CAUTION: Handle dry explosive with great care. Do not scrape or handle it roughly. Keep away from sparks or open flames. Store in cool, dry place.