Waste acid question about dropping iron.

Gold Refining Forum

Help Support Gold Refining Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

heliman4141

Well-known member
Joined
Aug 10, 2013
Messages
180
Hello,
Im raising my exhausted waste acid to around 2.5 PH with Soda ash then, I use very small iron trim nails added to drop the copper ( I have a LOT of trim nails from the old days before airguns took over, so my iron hoard is a big freebee) & other metals in the acid.
My question is one about safety from a health standpoint, I have several bottles of Drain cleaner thats main ingrediant is Sodium Hydroxide, which is obviously good for dropping iron but, the bottle also states it contains Sodium Hypochlorite & Sodium Silicate. Im not heating the solution at all, so will there still be a dangerious Chlorine gas possibility? If so Ill take it back & buy just pure Sodium Hydroxide if it is.
I searched but could not find an answer to this question, but I may have searched in a incorrect manner of wording I don't know. I just want to be as safe as possible at all times.
Thanks in advance,
Dave
 
I'm not the best one to answer this question but I think you should take it back and try to get the pure sodium hydroxide. I'm not sure if it would give off chlorine gas but I think there is a good chance it would. I don't know exactly what the sodium silicate would (or might) do but that's just one more chemical added to the mix. I assume your goal is to get this waste into a form safe to dispose of.

I looked up the MSDS for sodium silicate and it states:

Small Spill:
Dilute with water and mop up, or absorb with an inert dry material and place in an appropriate waste disposal container. If
necessary: Neutralize the residue with a dilute solution of acetic acid. Finish cleaning by spreading water on the contaminated
surface and dispose of according to local and regional authority requirements.
Large Spill:
Corrosive liquid. Stop leak if without risk. Absorb with DRY earth, sand or other non-combustible material. Do not get water
inside container. Do not touch spilled material. Use water spray curtain to divert vapor drift. Prevent entry into sewers,
basements or confined areas; dike if needed. Call for assistance on disposal. Neutralize the residue with a dilute solution
of acetic acid. Finish cleaning by spreading water on the contaminated surface and allow to evacuate through the sanitary
system.

Other than the possible chlorine gas, it looks like it MIGHT work to neutralise the acid and drop the iron but maybe someone else will confirm that. If you can get the pure sodium hydroxide or just lime like in lazersteve's post, What to do with Acid Peroxide after removing the gold foils, that should work better.
 
Yes,
Im planning on doing this last then disposing of it down the drain after filtering out solids.
My take on it was this: Its a drain cleaner product manufactured expressly for dumping down the drain so it being watered down shouldn't add any issues for the waste recycling setup for my citys sewer sys. but could be bad for anyone downwind of me so im concerned. It does state to carefully not breath the fumes etc. but I always filter, siphon, & do the nitric with a fan blowing sideways on it & I wear a P-100 acid resperator just incase the wind does a shift. Im just a tad concerned about the chlorine issue is all. Mainly anything or anyone downwind of me is my major concern, im not planning to do this just yet until I hear more input stating ya or nay & why.
All other chemicals I use are pure from my soda ash to my acids, this is my only non pure chemical & its the last part of the process so im very interested to hear if there is any issues as the nitric will be neutralized before I add this in to remove the iron. I could also neutralize the Muratic with ammonia & water dillution beforehand also.
The pure chemical is expensive to purchase & ship & I can buy this one for $4 a gallon all day long at the local Dollar store, that is why if its ok Ill gladly use it IF its reasonably safe in small portions & the reaction is not constant but short lived.
Dave
 
In that link above, lasersteve wrote:

Add lime ($4.50 for forty pounds at WalMart) dissolved in water until it turns clear and test pH 7 to litmus paper. The solution foams vigorously as the lime water is added. The neutralized salt water can now be disposed of without worries. The red brown iron compounds in the sediment can be dried out and sent to the local dump or melted with carbon to form crude iron.

I'm not sure what the current price is for lime but it shouldn't be much more than what that drain cleaner costs. A quick Google search shows that Lowes sells a 40 pound bag for $4.77 so it is still pretty cheap. Keep in mind the part about foams vigorously, I'm pretty sure the drain cleaner would do the same so make sure you have room in whatever container you use for the foaming.
 
Remember that bleach is used as an oxidiser so adding any to solutions with free hydrochloric will start dissolution again which will then be reduced by the lye so until all the free acid is used up your wasting money and time and creating chlorine gas just to add to the fun.
 
The chlorine gas is not a major problem as long as it's well ventilated before reaching anything....

When I shock my pool, I increase the free CL level first and then dump in excessive amounts of shock which is CL+umm...don't remember but it dissapates very quickly when exposed to air.
I get very strong CL smell for an hour or more right around the pool but disperses quickly.

I've had the CL gas take my breath away the first time I left my shed door open. Major changes in my air drafting. The first feeling is the overwelming urge to cough as never before. Doing so with CL gas in high concentration would cost life as it would be the only thing filling the lungs. Knowing this, I forced myself to not breath, cough or anything but run out the door to fresh air. In that instant I knew I made the mistake, my only thought was to get out to fresh air before breathing, coughing.
You don't want to ever experience that. Now I make sure the door is air tight before pouring HCL.

Point being, make sure there is plenty of air flow away from close contact and the CL gas wont be a problem short of the smell of it.
So adding other contaminants would be the only other thing to consider.

B.S.
 
A big thank you to all the members who answered my question,
I missed the use lime in the first answer to my question but thanks for mentioning it, id LOVE to use lime over this nasty cleaner anyday as its safe to handle. I quit smoking 15yrs. ago & am very protective of my lungs. All my family has perished from the dreaded & awful lung cancer due to work conditions & smoking , im the only one left, sigh..... but im always wearing a mask at work at my discretion, I get teased a lot over it but you know what they say, you reap what you sow. And everything is accumulative over time. I have enough health issues already don't need lung issues to compound them.
Cost is about the same too which is super, plus its a natural compound..im trying to avoid ANY additional acids period, my only pita about the whole process is waste disposal, but it has to be done right or my conscience will naw on me. Im a bit of a tree hugger when it comes to the enviorments water & air quality downstream of me.
Thanks again & Ill take the cleaner back today.

Dave
 
Go look in the new posts section as I have just posted what I have worked out as far as the overall processing of what I'm doing, when the weather gets nicer.

The last step, removing iron and everything else to make salt water I still need to work out but solution has evaporated fast enough so fat that I haven't needed to worry about dumping anything yet. But I'm working on learning now as this next warm patch of the year should produce enough end waste I'll have to deal with.

Good luck and hope to see that first gold button. Mine's still in the system's "collecting" step. Maybe this year I'll refine the refinning steps of the system.

B.S.
 
Pantherlikher said:
Go look in the new posts section as I have just posted what I have worked out as far as the overall processing of what I'm doing, when the weather gets nicer.

The last step, removing iron and everything else to make salt water I still need to work out but solution has evaporated fast enough so fat that I haven't needed to worry about dumping anything yet. But I'm working on learning now as this next warm patch of the year should produce enough end waste I'll have to deal with.

Good luck and hope to see that first gold button. Mine's still in the system's "collecting" step. Maybe this year I'll refine the refinning steps of the system.

B.S.

Hi Pantherlikher,
Been doing this going on 2 yrs. now & sadly I too am restricted by the weather here. If it was warm here yr. round id have already consumed all my materials as is being at the mercy of Mother Nature who is acting very strangly this yr. who knows? If the weather does not get its act together & stays cold & the price of Gold climbs id be tempted to just sell my 25-30lbs. hoard on Fleabay & be done with it. However I do enjoy seeing the fruits of my labor as gold beads. Made my first ones a few weeks ago. Came out great. Ill probably never sell them till im on my deathbed as im so attached to them.......was sooooooooooooooo time consuming to make. Id have made more profit flipping burgers im certain, LOL..................But it is an interesting chemestry lesson, and the bragging rites to non refiners is a justifiable reward in itself. I have a pic of my first Gold batch, it may be too large to be accepted in this post but Ill give it a try, you can also see it in the show your Gold area on this site also, nice pics in that area of some very large bars! Im as small time as it gets.............. :roll:

Dave
 

Attachments

  • Dave's Gold 002.JPG
    Dave's Gold 002.JPG
    443.4 KB · Views: 264
Back
Top