# what is this? waste treatment.



## nickton (Jan 16, 2021)

I didn't really want to start a whole new topic but just couldn't find any place to post these pictures of crystals I got from evaporating my final waste solution, after cementing with aluminum, then adjusting to a neutral ph with sodium bicarbonate and some sodium hydroxide (Briefly). I think it is simply salt: 

Well it is obviously some kind of salt.

As far as I can guess, the material left after evaporation would be anything above aluminum in the reactivity series, as well as baking soda and lye powders (???).

The orange/brown color must be iron oxide I think too.

I washed some of the salt crystals in water and have a jar of cleaned material I don't have a picture of yet. But it doesn't dissolve (at least easily) in water.

I have the earlier filtered precipitations in separate jars. Unfortunately since this was my first stock pot I had done a few things out of order, like adding salt, copper, and iron at various stages. I now have a better understanding of what to do.


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## nickton (Jan 16, 2021)

Here are some more pictures:


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## nickton (Jan 16, 2021)

I also saved the dirtier crystals:


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## FrugalRefiner (Jan 16, 2021)

Instead of "salt", I'd probably label that jar as "toxic waste". If it were mine, I'd hate to think that I might die someday, and someone would come along and think, "Oh look, old Dave had some special salt squirreled away. I'll have to try some of that on my next hamburger."

I know, that's a stretch, but it's the same reason not to use food containers like beverage bottles to store toxic liquids.

Dave


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## nickton (Jan 17, 2021)

yes that's probably a good idea. I don't plan to keep it that way too long anyway. I don't think it's too toxic at this point however, since I have cemented out whatever is below aluminum on the reactivity chart. 

Some people have said it is mostly iron oxide and salt. I don't think the added basic powders (baking soda, lye, some ammonia) caused any toxic reaction, but please by all means school me about this if I'm wrong. 

I had reached to the point where after attaining a neutral ph, I filtered out all solids, but since the water didn't turn clear, I decided there must be more in there. The only way I could think of to remove soluble remains, was evaporation, which gave me the brownish/orange goop and those crystals. 

It's a time consuming process, but I'd rather do it than flush down the drain. 

I now have a (well covered) five gallon bucket of this gunk. I think it contains mostly base metals and any pm's are in what I filtered out at earlier stages.

You're right about that salt though. I've seen similar looking stuff from the Dead Sea or Tibet I think. I wouldn't want someone to think it's medicinal.


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## FrugalRefiner (Jan 17, 2021)

I agree with everything you said. I just feel an obligation to be the voice of caution for anyone who may read this thread in the future.

Dave


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## nickton (Jan 23, 2021)

I guess no on wants to take a stab at identification.


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## UncleBenBen (Jan 24, 2021)

nickton said:


> I guess no on wants to take a stab at identification.



Get the test tubes out and test it. What does it dissolve in. What won't it dissolve in. Sounds like some fun experimenting to me!


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## nickton (Jan 26, 2021)

I guess that will have to be an entirely new field of research for me. I haven't a clue yet.


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## Geo (Jan 26, 2021)

Wrong shape for sodium chloride.


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## nickton (Jan 29, 2021)

aha. I was wondering about that. It did seem a little off to me but I wasn't sure why. I'd like to find a resource for crystal formation shapes perhaps. In fact I think I'll search it now. I notice these can become very long and straight. :mrgreen:


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## nickton (Jan 29, 2021)

Looks a bit more like magnesium sulfate. I think I'll try to re - crystalize some or them to see if I can get them cleaner or larger.


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## g_axelsson (Jan 29, 2021)

Crystal forms are like fingerprints for molecules. If you know the surfaces and the angles between them then you can identify the compound with a high confidence. For anyone interested the science is called crystallography ( https://en.wikipedia.org/wiki/Crystallography ), the science of packing atoms and molecules together into crystals. A stunning example is the nine volumes of Goldschmidt's Atlas of Crystal Forms. A bible for mineralogists.

There are a number of basic crystal forms, triclinic, cubic, hexagonal... if you study the form of the crystal you can put it into one of the major groups. Then list what metals could have ended up in solution in the end and what anions (sulfate, chloride, hydroxide...) is in the mix. The crystals are made from a mix of these.

Personally it looks like gypsum crystals, calcium sulfate, but I don't think it's so easy to make it into nice crystals on a lab scale. It probably needs geological time scale to work. At least years.

You could also test density and solubility easily enough.

Göran


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## nickton (Jan 30, 2021)

thanks for the links. I'll have to check them out.


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## nickton (Jan 30, 2021)

I tried the links and learned a lot, stumbling on "the gold museum", a great site for gold eye candy, containing an excellent section explaining gold crystal formations, and photos of many amazing nuggets. Can't figure out how to share the link but I do recommend it to those who haven't checked it out yet. :G

I'm think I will try to grow larger crystals from my stock pot material.


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## FrugalRefiner (Jan 30, 2021)

See Including Links.

Dave


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## Geo (Jan 30, 2021)

Calcium sulfate makes a really fluffy pearlescent white crystal that looks like powder. I accidentally made some trying calcium nitrate for poor mans AR. So I tested some in a non-metal processing test and it made the same fluffy white pearlescent powder.

Edit : It formed when I added SMB. I was scared and amazed.


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## nickton (Jan 31, 2021)

Here's some more detailed pictures of the crystals, from a new batch of evaporation:


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## nickton (Jan 31, 2021)

This one I thought looked best:


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## nickton (Jan 31, 2021)

I can rinse them off but they are pretty delicate and do seem soluble, dissolving slightly as I rinse them. They remind me a bit of ice. Though it is not freezing where I live, I wondered if this could be a mix of materials with a higher freezing point than water.


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## UncleBenBen (Feb 1, 2021)

Oh friend! Why are you handling that without gloves? I'm a firm believer that the only thing to be handled bare handed are the end metals. Not some unidentified crystals from my waste stream. Please put some gloves on!


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## nickton (Feb 1, 2021)

okay. Thanks for the concern. :mrgreen:

Maybe the corner store has some for sale. All my old ones are trashed.


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## nickton (Feb 1, 2021)

Okay I got the gloves. 

I however, am pretty sure it is not toxic. I cemented everything out below aluminum on the reactivity series, and am pretty sure the orange is from iron oxide, which leaves magnesium, sodium, calcium, potasium, and lithium, if I am not mistaken. I am guessing a mixture of those would not be too bad, since each alone is not toxic. I will however be safe just in case.

I must say that after attempting to find information on crystal identification, I am overwhelmed. It appears to be an incredibly complex and advanced area of science.


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## Martijn (Feb 2, 2021)

nickton said:


> Okay I got the gloves.
> 
> I however, am pretty sure it is not toxic. I cemented everything out below aluminum on the reactivity series, and am pretty sure the orange is from iron oxide, which leaves magnesium, sodium, potasium, and lithium, if I am not mistaken. I am guessing a mixture of those would not be too bad, since each alone is not toxic. I will however be safe just in case.
> 
> I must say that after attempting to find information on crystal identification, I am overwhelmed. It appears to be an incredibly complex and advanced area of science.



You have absolutely no idea what the crystal is or which processes took place in your reaction, but you're pretty sure it's not toxic? That's quite a statement. 

Baking soda you say? Could it be oxalic acid? Carbohydrates reacted with something in there? 

If so, from that MSDS: 
------------------
POISON! DANGER! MAY BE FATAL IF SWALLOWED. CORROSIVE. CAUSES SEVERE IRRITATION AND BURNS TO SKIN, EYES, AND RESPIRATORY TRACT. HARMFUL IF INHALED OR ABSORBED THROUGH SKIN. MAY CAUSE KIDNEY DAMAGE

I'm pretty sure everything in hydrometallurgy can be considered toxic and deadly. To be safe... do not lick!!! Its not salt!!!
Stay alive, be safe..


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## nickton (Feb 5, 2021)

Well I didn't get any skin irritation, burns, eye problems or anything else. I just washed my hands and everything's been fine. Sorry I scared you all. :mrgreen:

I wasn't touching it much anyways. I have a couple of spoons, large tweezers, and strainers to clean it in.


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## Martijn (Feb 5, 2021)

You did not scare me, I tried to scare you!! :wink: 
Not knowing what it is and not having acute symptoms does not mean something is safe to touch. 
Especially when you don't know what it is!
Nickel salts e.g. are basically all carcinogenic. 

My suggestion was just that: one of many possibilities. Food for thought. 

Stay healthy.


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## UncleBenBen (Feb 5, 2021)

Martijn said:


> You did not scare me, I tried to scare you!!



Same here! Not everything in refining will kill you quickly. It's the little things. It is the cumulative effect of heavy metals and breathing the fumes created. A little contact here. A bit more there. A whiff of this and that.

Then one day you find yourself having to take a break to climb a flight of stairs.

Just practice safe procedure. That simple. To banter to the contrary is just no good. So, again, please just be safe! :wink:


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## nickton (Feb 7, 2021)

I thought maybe some of you experts could give me an idea of what it is. I followed all the advice on waste treatment and yet no one else apparently has done this evaporation process at the end. I find it interesting that people are jumping on me after processing supposedly fully treated waste. Usually it is recommended to flush it down the toilet after neutralizing the acid and filtering, or at least that's the idea I got for some reason after studying many a post from Butcher and others. I think it is supposed to be salt water and iron oxide at that point.

By the way I do have a clue as to what the material is and I guarantee it will not prove toxic. More than just a hunch.


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## nickton (Feb 7, 2021)

Okay I take some of it back. Butcher mentions evaporation at the end, but nothing about crystal formation that I have found.


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## butcher (Feb 7, 2021)

Salts of metals and acids, or of the reagents involved.
Which metals, which acids, which chemicals were involved, what formed these salts?
What chemical changes or reactions were involved in making these salts?
What products were removed or what traces remain?
Were they recrystallized to make them purer?
Full of drag down contamination and or inclusion contaminated of insoluble or other chemical reactions?

While these salts are obviously not pure or made up of only one metal, or of one acid or one chemical reagent.


With possible metal oxides and hydroxides as well as metal particles, and other salts or combinations of other metal salts, with drag down and possible contamination of other reduced and oxidized metal contamination.

In the formation of salts, the process of crystalization will normally make the different types of metal/acid salt formation fairly pure, redissolving and recrystallization is a way to make the crystals of the salts purer with each recrystallization.

what are these salts? 
Well, obviously they are products of any metal, any acid, any base or caustic, or chemical reagent used in the process that created them.
Note while many of these metals and acids or salts can be dangerous to humans, harmful to animals and the environment, they can poison killing the soil's natural ability to grow plants.

While we treat our waste in a process to remove as much of the more deadly or toxic metals (and put them into a form that is less water-soluble, and less dangerous to us or our environment, ideally making these metals less toxic metals changing them into a more stable state as metal hydroxides then into metal oxides or even into elemental metal, removing the more toxic metals from the waste as much as possible, by displacing metals from solution by dissolving a more reactive metal that is less toxic (although very possible still toxic metal but less so), and removing other metals as oxides or insoluble hydroxides as much as possible, changing the solutions into less toxic forms before proper disposal of the insoluble, again if possible making the insoluble metal hydroxides, into safer metal oxides (roasting) or into elemental metals forms were possible before disposal. 

These less toxic salt solutions upon evaporation will form salts, containing any ions of the different metals, any of the acids, any of the different chemical or reagents, and any of the reactions of these that were involved in making them, although less toxic if the waste was treated properly, while safer (but not safe to eat, to put in soil or to dump down the drain or toilet), while most likely very similar to sea salt at this point it is still harmful and can still contain any metal acid or chemical that was ever involved in making these salts...

While you can probably touch the clear salt to your tongue and taste the clear salt and it may likely be a fairly pure form of sodium chloride, or some very reactive metal sulfate, you probably would not die today and you may see that it tastes just like table salt, or a combination of different metal chloride and or metal sulfate salts.

But why would anyone want to? you can determine something is acid or not by tasting it, Most chemists today have better ways of testing salts or acids than tasting them.

what are these salts? 

If you only used one metal and one acid to form these salts the answer would be simple.

Add a combination of different metals and several different acids and other chemical reagents and do a slew of magic tricks with the solution the answer becomes more complicated. and 

To tell what the different salt crystals are then you would need to look into testing for the different metal cations involved and tests of the different acids or basic chemical anions that are involved...

Well if you really want to know you can always test for each of the different (metal) cations and you can also test for the different Anions (acids or bases involved in these salts), although these different tests themselves can get fairly complicated as much of them seem to be processes of eliminations, making the testing a long drawn out string of many different tests, somewhat complicated processes to follow with many steps that must be done in certain orders not leaving any of the tests out of the series of tests, with many of the tests just eliminating what is not there, somewhat hard to follow chemical tests in order to get to the answers.

I would still consider these salts (or solutions) hazardous, and dispose of them properly.
Although after recrystallization of the ionic salts you probably have mostly a form of sodium chloride (table salt) with some other metals cations and nonmetal anions involved.

None of the processes we use in waste treatment can guarantee that we have the removal of (ALL) of the toxic ions of metals, or anions.

We just make it into a much safer slat or solution to dispose of, that still needs to be treated as toxic and still needs to be disposed of properly...


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## Martijn (Feb 8, 2021)

nickton said:


> I thought maybe some of you experts could give me an idea of what it is. I followed all the advice on waste treatment and yet no one else apparently has done this evaporation process at the end. I find it interesting that people are jumping on me after processing supposedly fully treated waste. Usually it is recommended to flush it down the toilet after neutralizing the acid and filtering, or at least that's the idea I got for some reason after studying many a post from Butcher and others. I think it is supposed to be salt water and iron oxide at that point.
> 
> By the way I do have a clue as to what the material is and I guarantee it will not prove toxic. More than just a hunch.



I think I understand your point of view now: you wonder why after the waste treatment process, and there should be only safe to discard water left, how can there still be something toxic in it? that makes no sense.. you're right. That would make no sense. 
But I get the feeling you did not follow procedure completely. You neutralized the solution after cementing? You need to raise the pH to at least 9 or 11 to push all the base metals out to below acceptable levels that can cause problems in nature or the sewage water plant.
You only neutralized the solution if I read it right. Leaving the Ph at 7 is not fully treated waste! You need to push out more salts as hydroxides. 

Evaporating is usually not done with waste, unless left in the baking sun for weeks, just filter and possibly neutralize the High pH water before dumping it in the sewer. But then again, how are toilets unplugged? NaOH or Sulfuric that goes straight in to the sewage. Just leave the Ph at 11, dump it, scare the rats away from your home and save on HCL or sulfuric. 

But that hunch you have may be based on partially faulty assumptions. (I have your health in mind)

Martijn.


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## butcher (Feb 8, 2021)

We cannot just raise the pH and push all of the unwanted metals out, different metals will stay in a solution at different pH ranges, while we can remove almost all of the less reactive metals we cannot remove them all.
https://heienv.com/hydroxide-precipitation-of-metals/

Some of the amphoteric metals in the solution will become insoluble as you raise the pH, and will precipitate, but if you raise the pH more they will redissolve back into the solution again at this higher pH range...


I go the extra step.
I dry all my waste, I roast the insoluble materials such as the hydroxides over a coal fire to change them from soluble salts or slightly soluble hydroxides to water-insoluble oxides or to metal powders.

I also evaporate the salt solutions to dry salts and dispose of them as hazardous waste (check your area for material waste disposal stations or household waste disposal drives, most cities or towns will normally have these drives at least once a year for households to dispose of their toxic wastes, unused chemical products old paints, and oils...


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## nickton (Feb 9, 2021)

Thanks for the explanation. I will certainly not lick anything and am wearing gloves now, saving the crystals in plastic containers that I will take to our hazardous waste facility. I didn't realize I should have raised the ph to 11 to get some more metals to drop. I didn't religiously check ph after dumping baking soda, some lye, and a bit of ammonia in but am sure it was at least 7. 
Another thing I did in one bucket as an experiment, was throw in a few unwrapped lithium batteries, since lithium is near the top of the reactivity series, so I think there is lithium in there. I also noticed that the crystals, when left out to dry, turn into white powder.

I now have a 5 gallon bucket of material and I will try roasting some. It will also go to the hazardous waste disposal site.


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## FrugalRefiner (Feb 9, 2021)

nickton said:


> I didn't religiously check ph after dumping baking soda, some lye, and a bit of ammonia in but am sure it was at least 7.



You may not realize, but ammonia can create explosive compounds with a number of metals in solution. It appears you dodged the bullet, given everything else you added, but it's not something you should repeat.




> Another thing I did in one bucket as an experiment, was throw in a few unwrapped lithium batteries, since lithium is near the top of the reactivity series, so I think there is lithium in there. I also noticed that the crystals, when left out to dry, turn into white powder.



Another bad idea in my opinion. I don't know where you found these ideas, but I don't think your methods are sound.

Dave


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## Lino1406 (Feb 9, 2021)

Li batteries (in the least case) will produce electrolysis, H2, O2. What for? Take them out


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## butcher (Feb 10, 2021)

I would fear the lithium metal, because of its reactivity, the metal is so reactive that it could start a fire in your lab or even possibly an explosion.

Waste treatment of toxic metals in solution, several metals are amphoteric, they may precipitate as you raise the pH (making it less acidic) by the addition of a basic or caustic salt, but as you raise the pH Higher( by adding more basic reagents) the metal will dissolve back into solution.

Looking at the chart we see nickel and chromium metal ions dissolved in an acidic solution, for example, chromium is an amphoteric metal, in the chart of the pH scale we see we may have a whole lot of toxic nickel and chromium ions dissolved in the acidic solution, as we raise the pH we see we can lower the concentration of chromium metal ions in solution by raising the pH (to say a pH of 4) where we may have over 100 milligrams of chromium in per liter of solution, and by raising the pH to 7.5 we get the lowest concentration of chromium ions in solution with around 0.1 milligrams of chromium in solution, but here we see we can still have a whole lot of poisonous nickel still dissolved in solution, to precipitate the nickle we need to raise the pH higher, but as we raise the pH towards being less acidic and more basic, we see that the precipitated chromium will begin to dissolve back into solution, as the nickle concentration in solution is lowered, at a pH of around 10 we can have around 10 milligrams of chromium dissolved in solution.

Note: at a pH where chromium ions are the lowest we can still have a lot of nickel in the solution, and as we raise the pH to precipitate the nickel the previously precipitated chromium dissolves back into solution...

So we can see we cannot get "ALL" of the chromium metal out of solution by using pH adjustments as our only means, we can lower concentration, and make the solution less hazardous or lower the concentration of these toxic metals but we do not remove them all.


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## nickton (Feb 13, 2021)

I guess you could remove most of the nickel first and then deal with the chromium.

By the way thanks to everyone for setting me right. This has been very educational.

I was wrong about the toxicity of those crystals then, and I appreciate the learning process.

I make a note of ammonia's potential for danger. I didn't use much of it however--just what was left in a small container of cleaner so I could throw out the bottle. 

And I don't plan on messing with lithium anymore either. I thought it might be an option for cementing less reactive metals, since it is high on the reactivity series list, and though I didn't notice any visible volatile reaction when adding a few unravelled batteries, it is best to be safe. Just about everyone has heard of lithium batteries exploding.

Also I don't do any of this in my shop. It's all out doors. 

Sometimes I have to simplify things so my layman's mind can remember correct procedures without knowing formulaic equations or other complex and to me confusing explanations. I am admittedly not a scientist, and that is why I like to present my occasionally flawed thinking here for feedback.


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