Australia's Science Forum

I need to wash some sand, for an experiment. Has anyone done an acid wash with sand?? Washing sand in warm soapy water, does not seem to do the job. So perhaps someone out their can enlighten me.


Thanks

I use 0.1M HCl to wash the sand. Put sand in glass beaker about 5-7cm on the bottom and cover in HCL. Stir with gass rod and wait until fizzing stops( when all shells and CaCo3 had dissolved), decant the acid and repeat until no more reaction. Then give it a very good rinse in tap water, last wash in distilled water and dry on a tray.
We have to do this with beach sand.
Have fun, Lada

Our washed sand jar was dropped a few weeks ago. I didn't worry too much because I haven't seen it used for anything yet. Where do you get the sand to start with? And what is it used for?
Rosalie

I pick up a little jar from the beach. We use it for reaction of acids with oxides, sand being silicon oxide. Needs to be acid washed because it should not react with acid. The impurities as carbonates(shells) will react.
Lada

Our sand was in the fire buckets, that came with the school, I guess. So just a small amount to wash, but had never been asked for this before.

Silly question for the day - What if the sand is coral sand? Does that mean it all dissolves when it is acid-washed?

Cheers, K

Yes, all carbonate based particles will disolve. The quartz part of sand (SiO2) will stay behind.
Lada

Sorry about the misprint in dissolve.

I've finally got around to washing some sand (because I was asked for it and of course we didn't have any!) and it turned yellow... I washed it again with water and the yellow came out into the water. The sand has dried again and is still yellow, although not as bad as before. I don't think it's and issue, but curiousity makes me ask if anyone knows where the yellow came from?

JUst done some more sand, and ours has also gone a amber colour????????????

Would this be due to iron in the sand? (would form FeCl3 with HCl).

I go to Bunnings and buy a snmall bag of acid washed sand,
a lot easier!!!

I go to Bunnings as well. Too easy, I really don't have time to be acid washing sand.