I know that cement mixture has Calcoum hydroxide, and im planning in extracting it. The cement im gonna use is portland cement, after a quick google
search i found out about its compounds. More than 80% of its compounds are water insoluble. So what i did is that i filtered the solution, and i
noticed some white residues that stayed at the bottom and after a period of 10 hours it compacted. So my question is, whats this white residue left at
the bottom? Whats the other filtered stuff? And how do i complete the extraction of calcium hydroxide?m1tanker78 - 11-5-2012 at 19:01
Portland cement contains a lot of silica. If nearly pure, it settles out nicely as a white or off-white solid. AFAIK, cement contains lime
(calcium oxide). This is the component that generates heat when mixed with water and initiates the curing process. The problem is that it's virtually
impossible to isolate the silica from the lime by filtration or settling alone. You'd have to react with HCL - that would react with the lime and
leave the silica. But you want the hydrated lime, not the silica..
If you want calcium hydroxide, why not buy a sack of hydrated lime. I see you're in PR so it's probably called "cal".
Tankvampirexevipex - 12-5-2012 at 03:00
Do you know any store to find it?weiming1998 - 12-5-2012 at 03:37
Gardening stores, as hydrated lime is a great alkalizer for the soil. It also increases the calcium content of the soil. I don't know about where you
live, but in Australia, you can get 2.5kgs for $3.
If you want to extract Ca(OH)2 from cement just for the fun of it, I suggest you dissolve it in an acid, then displace it out with NaOH/KOH and
filter.unionised - 12-5-2012 at 05:58
Portland cement is essentially a mixture of calcium silicates .
There isn't any hydroxide there. There's not much calcium oxide either.
