How to make kno3 pellets into fine powder

I bought 2 pounds of kno3 on amazon and thought it was powder. Any idea on how to make it into powder? I have a mortar and a pestle, but it takes way too long. I also have a coffee grinder, but it heats up, and I'm scared that it my ignite. Tell me your ideas on how to make it into powder. Thanks

If you have a pure sample of KNO3 then using a coffee grinder to turn it into a fine powder should be safe. I've done this before myself and was precautious. It might depend on what type of model you are using, not exactly sure on that. Nonetheless, you may try doing it this way, but grind it over incriments of time. i.e. allow it the KNO3 to sit in the loader part of the grinder and start the grinder to run for a small increment of time. Turn the grinder off and see if that forms the powder you need. If not, grind it some more until you get the desired result.

Other than that your best bet might be to go with the mortar and pestle even though it takes a while. If you do this what you might try doing is adding just a few drops of water to your KNO3. KNO3 is slightly soluble in water. By adding only a few drops of water though, the KNO3 should become easier to grind down and should occur faster. Note though that if you add too much water that KNO3 will ionize in the solution, and you don't want that to happen. Go with 3-5 drops and you should be just fine.

Hope this helps some, good luck!