Portland Cement and high pH

[Hobster]

Randy, When making aragocrete or frag plugs, what is it in Portland Cement that makes the pH rise so much? And other than the pH rise are any of the compounds a problem in the tank?

http://en.wikipedia.org/wiki/Portland_cement

 

[Randy Holmes-Farley]

From that link:

"The raw materials for Portland cement production are a mixture (as fine powder in the 'Dry process' or in the form of a slurry in the 'Wet process') of minerals containing calcium oxide, silicon oxide, aluminium oxide, ferric oxide, and magnesium oxide."

The calcium oxide and magnesium oxide both hydrate to the hydroxide form, and will boost pH a lot.

 

[Hobster]

Thanks.
So from that we could dose portland cement (calcium hydroxide) to boost Ca/ALK and the ferric oxide would control the phosphates.:lol:

 

[Randy Holmes-Farley]

Yes, sounds like the perfect combo.