Cleaning beerstone {was: Re: [Rockhounds] muriatic acid for cleaning...!?????!!!}

[Kreigh Tomaszewski]

If you end up with calcium oxalate, how do you clean it off? It is not
very nice stuff.

Calcium oxalate turns up as a byproduct of brewing beer, coats tanks,
and opens the door for spoiled batches. The crystals shield undesirable
organisms. The industry calls it beerstone, and takes measures to
control it. 

As a rockhound you might know it as Whewellite. 

Calcium oxalate also appears in some poisonous plants, and is a major
component of kidney stones. When ingested, even small dosages are very
not nice to humans -- and moderate doses can kill you. It is why you
don't eat rhubarb leaves.

The beer industry uses periodic treatment with caustic (2-4% lye) hot
(185F) water solution followed by warm (140F) phosphoric acid (1-2
oz/gallon) _OR_ a warm phosphoric/nitric acid solution (1-2 oz/gallon)
followed by a warm noncaustic alkaline cleaner (1-2 oz/gallon). Both
assume a final (usually high pressure) hot water rinse followed by tap
water until drain ph is neutral to the tap water. The acid and alkaline
compounds can neutralize each other, and be diluted, if a sufficient
holding tank is in the drain; 15-30 minutes flow treatment per stage.

Have any of you successfully cleaned calcium oxalate (off, probably,
quartz)? What worked?

Kreigh


Flint Smith wrote:
> 
> Just so we're complete here, HCl is used as a pre-treatment if you plan to remove rust stains using oxalic acid.  The plan is to avoid forming calcium oxalate.
> 
> Right?