Nice and cheap and relatively pure
So I use potassium nitrate for various purposes and this is an excellent source of relatively pure potassium nitrate. However, the 99.8% pure is slightly misleading. This fertilizer grade KNO3 is basic, coming in at a pH of 9.2-9.5 which is what I’d expect with fertilizer grade. Using the same saturated solution of KNO3 and water, the amounts of carbonates it possess is about 4250 parts per million, the amount of nitrites present is about 500 parts per million, and the amount of calcium carbonate is about 4000 parts per million. Upon dissolving in water, the color is slightly yellow, with some floating solids. After filtration, there is a few grams of sand like material, a few grams of clay like material, and a few dozen micrograms of ferrous material. Altogether it came to about 4 grams. All together, these impurities make up almost 13 grams in a 1000 gram batch of dissolved solids while recrystallizing, making it closer to 98.5-99% pure potassium nitrate. While this is good enough for me, they had claimed it was 99.8% pure potassium nitrate which is nearly an order of magnitude more pure than it actually is and I find that somewhat misleading. All in all though, for the price and, I can’t beat it without having more solid and insoluble impurities in here. I have 4 stars due to the misleading quality but I’m willing to change it, if possible, to 5 stars if they reanalyze and are more honest in its quality.
