vampirexevipex - 18-4-2012 at 18:29
Hello, i been wondering if someone can extract a calcium compound from milk, like for example: calcium phosphate or calcium carbonate. Cause i have
been doing some research in getting pure compounds from common foods ( like bananas which you can get potassium carbonate ) so i would like to try
with milk, but i dont know where to start. So can someone help?
mycotheologist - 19-4-2012 at 11:20
It would be an insanely tricky task trying to obtain PURE calcium salts from a complex mixture milk. Milk is an emulsion so the first thing I would
try is adding salt to separate it into 2 layers. Then you'd collect the aqueous layer and discard the other layer. You would then have an aqueous
solution of God knows how many water soluble compounds. After that you'd have to exploit calcium carbonates unique solubility characteristics to
isolate it further.
vampirexevipex - 19-4-2012 at 13:06
Hmmm ok thanks.. ill be trying that 
Chemistry Alchemist - 19-4-2012 at 21:56
just a guess but could u add vinegar to it to make the protein separate? then you may also have calcium acetate in the solution, maybe you can
separate it that way?
bbartlog - 20-4-2012 at 06:37
If you add acid you will indeed coagulate the proteins (you're on the way to making homemade cottage cheese...). However as I recall most of the
calcium ends up with the casein, in the curds; not as a calcium salt in the whey. Whey has a little over 100mg per liter of calcium versus 250mg/cup
for skim milk, i.e. only about a tenth as much as milk. Now, maybe that's for whey made using rennet, and using various acids will result in more
calcium in the non-proteinaceous solute; but you would need to research it.
If you're comfortable incinerating stuff, the simplest (if not necessarily easiest) way to get a calcium salt out of this is to dry the milk to a
powder and heat it in air until all the organics are gone (say at 800+ deg C). Could be done with a torch. You'd also have some Mg and such but that
is a separate issue.
unionised - 20-4-2012 at 09:40
If you roasted dried milk with phosphoric acid in air you would get impure calcium phosphate, but it would be an absurdly expensive way to do it.
[Edited on 20-4-12 by unionised]