Sciencemadness Discussion Board

Pinkish KNO3 Crystals

artemov - 5-2-2020 at 19:32

My KNO3 crystals seem to be a bit pinkish, is it normal?

Obtained from KCl and Calcium Ammonium Nitrate (both pure white). The supernatant is clear and colorless too.

20200205_151302.jpg - 73kB 20200206_112330.jpg - 60kB

[Edited on 6-2-2020 by artemov]

Abromination - 5-2-2020 at 20:25

I would give it a quick recryst, but for most uses it is probably pure enough. What are your reagent sources?

artemov - 5-2-2020 at 21:09

Quote: Originally posted by Abromination  
I would give it a quick recryst, but for most uses it is probably pure enough. What are your reagent sources?


Yah I will be recrystallizing later. CAN is for horticulture, but supposedly >99% pure. KCl is AR grade, but from China ...
Cheers.

Tsjerk - 6-2-2020 at 00:53

Quote:
The colour of potash varies (from white to dark red) based on its iron content. Typically, potash that contains more iron will be more reddish in colour. Our potash grades that range from light pink to dark red in colour, do so because of the different levels of iron oxide naturally occurring in the potash ore


Link

Edit: wrong quote

[Edited on 6-2-2020 by Tsjerk]

artemov - 7-2-2020 at 18:55

Quote: Originally posted by Tsjerk  
Quote:
The colour of potash varies (from white to dark red) based on its iron content. Typically, potash that contains more iron will be more reddish in colour. Our potash grades that range from light pink to dark red in colour, do so because of the different levels of iron oxide naturally occurring in the potash ore


Link

Edit: wrong quote

[Edited on 6-2-2020 by Tsjerk]


It is indeed some kind of contamination. After recrys, the nice crystals near the top are pure white, while the compacted crystals at the bottom are pinkish.