In the past, the most common way to get potassium nitrate - also known as saltpetre - was to harvest bat guano. Today, however, there is an easier way to source the ingredients needed to synthesize this basic component of many scientific experiments, fertilizers and gunpowder. All it takes is a couple of instant cold packs, a jar of sodium-free salt, and you're done. Read on to get started.
Steps
Step 1. Buy the ingredients
You can synthesize potassium nitrate using ingredients available at any pharmacy. Be sure to read the labels on the ingredients you will be sourcing to make sure they contain exactly what you need. Here's what to buy:
- An instant cold pack made with ammonium nitrate. It takes 40 grams.
- A container of sodium-free salt, i.e. potassium chloride. It takes 37 grams.
- In case you don't have one, get a food scale in order to accurately measure the necessary doses of each ingredient.
- You will also need a fine mesh filter to filter the final solution.
Step 2. Measure 100 milliliters of water
Use a cylinder or measuring cup to measure the exact amount.
Step 3. Dissolve 40 grams of ammonium nitrate in water
Pour them into the glass containing the water and stir slowly every couple of minutes until the granules are completely dissolved. It is an operation that takes little time.
Step 4. Filter the solution with a fine mesh filter
Cover the glass with a filter and filter the solution into a saucepan, this will retain any traces of ammonium nitrate left in the solution.
Step 5. Add 37 grams of potassium chloride and heat the solution
Heat it slowly over low heat, stirring regularly until the potash is completely dissolved. Do not let the solution come to a boil.
Step 6. Filter the solution into a freezer container
Use another filter to get rid of additional grainy traces. You can filter the solution into a plastic or glass container, as long as it is suitable for freezer storage.
Step 7. Cool the solution in the freezer
As it cools, nitrate crystals will begin to form. You can check the solution every couple of minutes to see where the process is. When the formation of more crystals seems to have stopped, the process will be finished.
Step 8. Drain the remaining liquid
Once crystal formation is complete, liquid ammonium chloride will remain. Drain this liquid so that only the crystals remain in the container. Let them dry completely before grinding them and before using potassium nitrate in your scientific experiments, or for other purposes.
