Disposal of muriatic acid?

[Evad Nomenclature]

Hey guys...

I've seen tons of threads about how to dispose of Ferric chloride, but none of the threads about muriatic that I've seen have mentioned disposal of it.

I just etched my first boards using muriatic and hyd. peroxide mixture... when I searched on google, there was one thread I found, and the guy said a lot of ways on how *not* to dispose of it, but not actually how to do it... silly eh?

So how about it?

[DougH]

Check with your local sanitation department. If we call our garbage men, they will make special pick ups of chemicals and other dangerous substances. Muriatic acid is fairly common, as it is used for swimming pools. The local authorities should have a provision for disposing of it.

[David]

Evad:  I do boards with this method also.  The amount of muriatic acid and peroxide mixture required to etch is quite small.  I have diluted by a factor of 200 or so and flushed it.

[culturejam]

Evad:  I do boards with this method also.  The amount of muriatic acid and peroxide mixture required to etch is quite small.  I have diluted by a factor of 200 or so and flushed it.

I'm thinking this is the most practical and safe way to do it. Mass dilution along with slow, metered disposal is the ticket.

My father worked for years at food additives production plant and was liaison to the local EPA office. He had to manage the process of safely pumping once-dangerous chemicals into the local eco system. I told him that I was using muriatic to etch copper, and he recommended a super-high dilution factor (with water) followed by flushing. Apparently the issue is that the copper in solution is highly toxic to just about any kind of living thing, and if you dilute it enough and spread out the "dumping", you can avoid toxicity. But that's purely anecdotal, so that it for what it's worth.

[MikeH]

I've heard that neutralizing it with baking powder and mixing up with concrete with create environmentally-inert bricks.  Etch enough boards and you could build yourself a castle.

[culturejam]

I've heard that neutralizing it with baking powder and mixing up with concrete with create environmentally-inert bricks.  Etch enough boards and you could build yourself a castle.

I've been using it for about 6 months and have etched maybe 50 boards or so, and I still haven't disposed of any (other than what is lost naturally through pouring back and forth between containers, etc). I just add tiny amounts of acid and 40-volume H2O2 (having good peroxide is the key). Takes maybe 40 minutes to etch a medium-sized board, but it sure beats having to throw it away every time.

[Barcode80]

I've heard that neutralizing it with baking powder and mixing up with concrete with create environmentally-inert bricks.  Etch enough boards and you could build yourself a castle.

I've been using it for about 6 months and have etched maybe 50 boards or so, and I still haven't disposed of any (other than what is lost naturally through pouring back and forth between containers, etc). I just add tiny amounts of acid and 40-volume H2O2 (having good peroxide is the key). Takes maybe 40 minutes to etch a medium-sized board, but it sure beats having to throw it away every time.

hmm, interesting. I've been getting crazy variances in etching time depending on the bottle of h202 i use. I bet there is either some inconsistency to the batches of H2O2 sold in the 3% form or i need to get a better brand or higher mixture.

i also dilute to a factor of about 100 and flush.

[fluoreszenz]

Hey guys...

I've seen tons of threads about how to dispose of Ferric chloride, but none of the threads about muriatic that I've seen have mentioned disposal of it.

I just etched my first boards using muriatic and hyd. peroxide mixture... when I searched on google, there was one thread I found, and the guy said a lot of ways on how *not* to dispose of it, but not actually how to do it... silly eh?

So how about it?

Don't flush it down, copper (in your etch solution) will kill the very useful bacteria in your local waste water treatment plant.

Copper is biostatic, eventually someone will be able to trace it  from which household the copper comes from.

Better check with your communities waste disposal office 

[culturejam]

hmm, interesting. I've been getting crazy variances in etching time depending on the bottle of h202 i use. I bet there is either some inconsistency to the batches of H2O2 sold in the 3% form or i need to get a better brand or higher mixture.

I really like the Clairoxide 40-volume peroxide. It's 12% H202, and it's really cheap. I think I paid $4 for a 16-ounce bottle. You can get it online or at most beauty supply shops. Some places also call it "developer". Just make sure that whatever you get is just peroxide and water, and not some kind of gel.

Seriously, it literally takes maybe 5 or 6 drops to turn my muriatic from dark ugly green to a brilliant emerald color. It rocks.

Here's a link so you can see what it looks like:
http://www.sallybeauty.com/Clairoxide-40V-Clear-Developer/SBS-320846,default,pd.html

[sean k]

I just did a little reading up on muriatic acid, which is spirit of salts or hydrochloric acid in water, and the method to neutralise it was to add it to a solution of lime and water, which released chlorine and/or hydrogen into the air and left the rest neutral.

This though did not take into consideration the added hydrogen peroxide and the dissolved copper.

[sean k]

But, after some more reading on muriatic acid, we don't get rid of it at all. We re- oxygenate the solution with a fish tank aerator and even add a little copper so it goes green again, from brown, and the solution now is  reusable as a... it's beyond me to explain but if you search the muriatic you'll come accross the reusable solution that hydrochloric/peroxide is the starter for.

[rnfr]

yeah, i thought the big deal about this stuff is that you DON'T have to throw it away.  i've also heard that you can simply leave it an uncapped container-provided it is a safe place with plenty of ventilation- and it will reoxygenate( ) after a while.

[DougH]

I just did a little reading up on muriatic acid, which is spirit of salts or hydrochloric acid in water, and the method to neutralise it was to add it to a solution of lime and water, which released chlorine and/or hydrogen into the air and left the rest neutral.

This though did not take into consideration the added hydrogen peroxide and the dissolved copper.

BE CAREFUL!

Hydrogen gas is *extremely* flammable. (Seen those photos of the Hindenburg?) And make sure you are in a well-ventilated area (preferably outside) if you are releasing Chlorine gas.

[mac]

I use MA at my construction sites to clean concrete stain on new doors and windows to be varnished.
MA reacts with concrete and calcium wall plasters. You can make it react before flushing/trashing if you donate to Greenpeace.
MA is not dangerous and the products of the reaction with calcium or similar in the quantities your are going to use are small.
Believe me, I should be seriously burned or dead by now.

mac

[MikeH]

I use MA at my construction sites to clean concrete stain on new doors and windows to be varnished.
MA reacts with concrete and calcium wall plasters. You can make it react before flushing/trashing if you donate to Greenpeace.
MA is not dangerous and the products of the reaction with calcium or similar in the quantities your are going to use are small.
Believe me, I should be seriously burned or dead by now.

mac

It's not the acid that's bad to flush, it's the dissolved copper

[Barcode80]

I use MA at my construction sites to clean concrete stain on new doors and windows to be varnished.
MA reacts with concrete and calcium wall plasters. You can make it react before flushing/trashing if you donate to Greenpeace.
MA is not dangerous and the products of the reaction with calcium or similar in the quantities your are going to use are small.
Believe me, I should be seriously burned or dead by now.

mac

It's not the acid that's bad to flush, it's the dissolved copper

yes, but the levels of copper contained within are so small that by the time the copper goes through he water system and is introduced to the volume of water within, it is virtually harmless. additionally, there is more copper on average disposed of each year in landfills by people throwing away pennies than is actually introduced to the water system by home users of industrial chemicals. food for thought.

[mac]

yes, but the levels of copper contained within are so small that by the time the copper goes through he water system and is introduced to the volume of water within, it is virtually harmless. additionally, there is more copper on average disposed of each year in landfills by people throwing away pennies than is actually introduced to the water system by home users of industrial chemicals. food for thought.

Exactly. Also remember that there is copper and other metals dissolved in water naturally.

mac

[davent]

I use MA at my construction sites to clean concrete stain on new doors and windows to be varnished.
MA reacts with concrete and calcium wall plasters. You can make it react before flushing/trashing if you donate to Greenpeace.
MA is not dangerous and the products of the reaction with calcium or similar in the quantities your are going to use are small.
Believe me, I should be seriously burned or dead by now.

mac

It's not the acid that's bad to flush, it's the dissolved copper

Is there a safe/easy means to precipitate the copper out of this etchant?

dave

[jimbob]

Dump it in your neighbors yard (bushes, rocks ect..) late at night after a dozen beers or use one of those empty beer bottles to pour it in and recap and toss it in w the trash.