Isolating a small amount of monoammonium phosphate from potassium dihydrogen phosphate
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In the process of preparing potassium dihydrogen phosphate using the double-displacement method (reaction between potassium chloride and monoammonium phosphate), after the first crystallization, the P2O5 content is around 52.5%, K2O is around 29%, and Cl is 1-2%. After recrystallization, the P2O5 content is around 53%, K2O is 32-33%, and Cl is 0.1%. The industrial standards require a P2O5 content of 52%, K2O levels above 33.5%, and a Cl content below 0.2%. Based on the results of recrystallization, it is clear that monoammonium phosphate is still present in the mixture. I would like to ask experts how to prevent monoammonium phosphate from being precipitated along with the other components during recrystallization. Thank you. . .
{:3_53:}{:3_57:} What are those other ten-odd points of yours? Crystalline water?
{:3_46:} Add more hydrogen, oxygen, and potassium oxide? Another question is whether it’s possible to adjust the crystallization speed; if it’s too fast, it’s easy for other salts to be carried out as well
Thank you. . . Add more hydrogen, oxygen, potassium oxide? Is it to increase the potassium content? The price of potassium hydroxide is between 7,000 and 8,000, which is a bit expensive; industrial-grade potassium dihydrogen phosphate costs around 6,000. . . I used a cooling rate of 10°C/h; it wasn’t strictly controlled, and a constant-temperature water bath was used for the experiment
This substance has a very low content of crystalline water; it’s not calculated in that way. The chemical formula for potassium dihydrogen phosphate is KH2PO4, and based on this formula, the percentages are approximately 52.5% for P2O5 and 34.5% for K2O. These two percentages do not add up to 100, as phosphorus and potassium are usually expressed in terms of their oxides
Aren’t you trying to remove ammonia here? It simply involves raising the pH level, or using negative pressure to remove ammonia gas and drive it away; using heating to expel ammonia gas would likely result in high costs. . . . You can try raising the temperature a bit, then stir while applying negative pressure
:lol looking forward to good news {:3_53:}
{:3_50:} I forgot it was bicarbonate; I guess ammonia can’t be released, right? Dihydrate is acidic, isn’t it?
{:3_50:} Hydrogenation, oxygen, and potassium are incorrect. . .
{:3_68:} Check whether your initial solution can be heated to create a negative pressure, so as to see if some of the ammonium chloride can be removed; if that doesn’t work, try adding some salt or acid
{:3_61:}This building is incorrect