I used a blender to mill the potassium nitrate granules into finer powder, which worked just fine except that some of the KNO3 got between the rotating knife and the container's pivot. (See picture
https://www.google.rs/url?sa=i&rct=j...13618772565000
) Anyway KNO3 is moderately soluble in water, so washing it was not a problem, except for that part between the rotor and the pivot. White solid coating is now permanently attached to the plastic and is not going away.
I tried scrubbing hard with water, no use.
Tried the same with acetic acid, no use. Tried to leave it immersed in acetic acid over night, nothing.
I even tried to use chlorine (bleach), it still won't go away.
I am assuming the KNO3 in that area was exposed to increased pressure and temperature, although I doubt that either of those was anything grand.
I kept the blender going for a full minute, so temperature could have gotten maybe to 50-60 Celsius (122-140F) at most.
My question is, what kind of reaction happened here?
Is the white solid coating still KNO3 or is it something else?
How can I dissolve the white solid coating?