Martijn said:
butcher is the king at killing several birds with one stone, but one use would be to cement the other metals out of solution with iron, filter the solution, then evaporate it for ferrous sulfate.
Dave
Dealing with Waste
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butcher is the king at killing several birds with one stone, but one use would be to cement the other metals out of solution with iron, filter the solution, then evaporate it for ferrous sulfate.
Dave
Dave,
See? I have learned from you how to be frugal, along with the many other things I learn here.
Sulfuric can also be used to make and distill nitric acid, distilling leaves behind the byproducts, that themselves may be useful in some other process or reaction...
See? I have learned from you how to be frugal, along with the many other things I learn here.
Sulfuric can also be used to make and distill nitric acid, distilling leaves behind the byproducts, that themselves may be useful in some other process or reaction...
Martijn
Well-known member
Dave, will the ferrous sulphate be good enough to drop gold considering the mainly zinc and other more reactive metals that might be in there from stripping plated items? Because its above iron in the reactivity series and would not have cemented out on iron? A lot of pins were brass so zinc should be expected right?
I don't expect to have more sulfuric waste like this anytime soon and maybe will re-acidify some of the hydroxide with sulfuric from evaporating or with fresh sulfiric to make some FeSO4 crystals. The >Ph6 hydroxide precipitate will contain mostly iron hydroxide, looking at the Ph precipitation chart given earlier in this thread. Zinc should start to fall out at a higher Ph level.
I will try some small tests heating and evapoating the solution to see if any soda drops out and what is left over, and another test diluting the solution down to a 1:1 ratio with tap water and adding more soda ash to one and lye to another diluted batch.
I am thinking of trying calcium hydroxide or calcium oxide for beter setling hydroxides.
I get a lot of hydroxide volume using soda ash and storage space is getting scarse.
Will post my results (assumptions
) here for futher comments, corrections and guidance in new and unexpected directions.
Thanks for the advice so far.
I don't expect to have more sulfuric waste like this anytime soon and maybe will re-acidify some of the hydroxide with sulfuric from evaporating or with fresh sulfiric to make some FeSO4 crystals. The >Ph6 hydroxide precipitate will contain mostly iron hydroxide, looking at the Ph precipitation chart given earlier in this thread. Zinc should start to fall out at a higher Ph level.
I will try some small tests heating and evapoating the solution to see if any soda drops out and what is left over, and another test diluting the solution down to a 1:1 ratio with tap water and adding more soda ash to one and lye to another diluted batch.
I am thinking of trying calcium hydroxide or calcium oxide for beter setling hydroxides.
I get a lot of hydroxide volume using soda ash and storage space is getting scarse.
Will post my results (assumptions
) here for futher comments, corrections and guidance in new and unexpected directions. Thanks for the advice so far.
kernels
Well-known member
I use Magnesium Oxide to precipitate Iron Hydroxide from waste, seems to settle fairly well. I think it was recommended by 4Metals in the original waste processing thread.
Martijn said:
Hi Martijn
Make sure that you don't confuse two situations here. You may have metal salts and compounds in your solution from the dissolving phase however their effect is not the same as dropping a bar of say, Zinc into the solution. Treat your solution as a murky mess of different compounds however you don't automatically drop your gold with those compounds in your solution until you add something new and cause another chemical reaction whether that be a replacement reaction or straight reduction. The short version is that you can forget the zinc from the brass, or iron from pins that is in solution for the purposes of getting your gold.
Therefore adding Ferrous Sulphate to your pregnant solution will still work all things being equal.
Jon
Let us take for example the concentrated sulfuric waste from the sulfuric cell.
Adding it the acid carefully to water (safety) to dilute the acid, the gold will cement from solution.
Now, this dilute solution will hold all of the metals that are still soluble as sulfates.
Say for some reason we have a little HNO3 and HCl mixed in with this mainly sulfuric acid waste.
Adding iron will cement most all of the metals less reactive than iron, like cadmium, cobalt, nickel, tin, lead, bismuth copper...
After decanting will leaving us with an iron sulfate solution with the other metals more reactive than iron in solution, such as chromium zinc, manganese aluminum, magnesium, sodium, barium, potassium, and lithium.
Evaporating the solution down to a green salt will concentrate the iron sulfate as crystals, which when forming will push the impurities and other metal out of the crystal matrix bond, leaving most of the metals more reactive than iron in solution.
During the evaporation process, the other more volatile acids will decompose and volatilize, water being first then nitric and then HCl, sulfuric will not volatilize as it has such a high boiling point than water or the other acids.
When making the copperas, we can remove the iron sulfate from the more reactive metals in the solution like zinc, by using crystallization, evaporating the copperas to salt, after removing crystals, rinsing, and then rewetting the with dilute H2SO4, and we can then recrystallize the copperas salts to get an almost pure copperas from the solution.
Now from what was waste we now will have a product we can use to test for gold dissolved in solution, a reagent-grade product we can use to precipitate gold with.
Adding it the acid carefully to water (safety) to dilute the acid, the gold will cement from solution.
Now, this dilute solution will hold all of the metals that are still soluble as sulfates.
Say for some reason we have a little HNO3 and HCl mixed in with this mainly sulfuric acid waste.
Adding iron will cement most all of the metals less reactive than iron, like cadmium, cobalt, nickel, tin, lead, bismuth copper...
After decanting will leaving us with an iron sulfate solution with the other metals more reactive than iron in solution, such as chromium zinc, manganese aluminum, magnesium, sodium, barium, potassium, and lithium.
Evaporating the solution down to a green salt will concentrate the iron sulfate as crystals, which when forming will push the impurities and other metal out of the crystal matrix bond, leaving most of the metals more reactive than iron in solution.
During the evaporation process, the other more volatile acids will decompose and volatilize, water being first then nitric and then HCl, sulfuric will not volatilize as it has such a high boiling point than water or the other acids.
When making the copperas, we can remove the iron sulfate from the more reactive metals in the solution like zinc, by using crystallization, evaporating the copperas to salt, after removing crystals, rinsing, and then rewetting the with dilute H2SO4, and we can then recrystallize the copperas salts to get an almost pure copperas from the solution.
Now from what was waste we now will have a product we can use to test for gold dissolved in solution, a reagent-grade product we can use to precipitate gold with.
rickzeien
Well-known member
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"Evaporating the solution down to a green salt will concentrate the iron sulfate as crystals, which when forming will push the impurities and other metal out of the crystal matrix bond, leaving most of the metals more reactive than iron in solution."
How is the disposal of this portion handled?
Sent from my SM-G950U using Tapatalk
How is the disposal of this portion handled?
Sent from my SM-G950U using Tapatalk
Just as we were doing before we are dealing with waste, we are just making a byproduct in the meantime.
Just as we would have previously, we are still dealing with waste, at this point, we have already removed many of the metals less reactive than iron, like cadmium, cobalt, nickel, tin, lead, bismuth copper...
When we previously used the iron metal to cement these metals from the solution.
After removing the copperas crystals leaveing us the more reactive metals in a concentrated sulfate solution.
Now we can carefully add a caustic or alkali to neutralize the acid, precipitate out metal oxides and hydroxides, such as chromium zinc, manganese aluminum, magnesium, sodium, barium, potassium, and lithium.
(note the caustic could also be an alkali caustic waste left over from some other process)...
Bringing the pH up to around 9 to 10, decanting hydroxides, and then adding a touch of acid (or other acidic waste) to lo lower pH to around 7 to remove the remaining metal hydroxides. leaving you with the concentrated saltwater to evaporate, I dry and roast the metal powders to drive off any remaining acids, and to form safer metal oxides to dispose of.
Just as we would have previously, we are still dealing with waste, at this point, we have already removed many of the metals less reactive than iron, like cadmium, cobalt, nickel, tin, lead, bismuth copper...
When we previously used the iron metal to cement these metals from the solution.
After removing the copperas crystals leaveing us the more reactive metals in a concentrated sulfate solution.
Now we can carefully add a caustic or alkali to neutralize the acid, precipitate out metal oxides and hydroxides, such as chromium zinc, manganese aluminum, magnesium, sodium, barium, potassium, and lithium.
(note the caustic could also be an alkali caustic waste left over from some other process)...
Bringing the pH up to around 9 to 10, decanting hydroxides, and then adding a touch of acid (or other acidic waste) to lo lower pH to around 7 to remove the remaining metal hydroxides. leaving you with the concentrated saltwater to evaporate, I dry and roast the metal powders to drive off any remaining acids, and to form safer metal oxides to dispose of.
rickzeien said:
You should realistically hire a consultant (you already know who) to help you work through your waste treatment/disposal. Since you can't legally discharge the saltwater without analysis & permitting, letting someone else treat it is often the best solution....I'm basing this opinion on the size equipment you are posting.
rickzeien
Well-known member
- Joined
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Sound advise. I use a American Waste Haulers. Not just for compliance and safety but also for liability reasons.snoman701 said:
I do however like to pre process as much as possible as to keep my waste disposal and handling cost to a minimum.
No sense in earning money only to pay it out in fines, excess insurance cost or lawsuits.
https://www.americanwastehaulers.com/hazardous-waste-disposal-columbia
Sent from my SM-G950U using Tapatalk
Martijn
Well-known member
To let you all know how it went with the first test with the soda-saturated sulfuric cell+ waste; letting it cool over night pushed out a kilo of soda. Filtered that and I evaporated the Ferrous sulfate solution down to a point where even more soda ash dropped out. I let it cool and ran it through a coffee filter. Rinsed the filter with tap water.
Evaporated solution with, i assume, soda pushed out?
Filtered solids.
Filtered solution left to cool overnight. Lead nitrate crystals i think. Further testing needed.
I will use the dirty soda on future wastes to form hydroxides after raising Ph with magnesium oxide to +\Ph2
The green solution will be filtered and cooled first in the freezer before a second attempt to make some copperas.
More byproducts to store and find a purpose for. Great idea Butcher.
Will keep you updated on the copperas. i.m thinking of freezing the green solution before a second attempt to make copperas.
Unfortunately this copperas wasn't ready yet to drop my sulfuric cell gold last night, but SMB did the trick just fine. here's a pic. of it dried. after following the recommended rinses and washes.
I want to share a picture of my first button too, is there a thread for that?
Thanks so much so far for all the great help you all!
Martijn.
Evaporated solution with, i assume, soda pushed out?
Filtered solids.
Filtered solution left to cool overnight. Lead nitrate crystals i think. Further testing needed.
I will use the dirty soda on future wastes to form hydroxides after raising Ph with magnesium oxide to +\Ph2
The green solution will be filtered and cooled first in the freezer before a second attempt to make some copperas.
More byproducts to store and find a purpose for. Great idea Butcher.
Will keep you updated on the copperas. i.m thinking of freezing the green solution before a second attempt to make copperas.
Unfortunately this copperas wasn't ready yet to drop my sulfuric cell gold last night, but SMB did the trick just fine. here's a pic. of it dried. after following the recommended rinses and washes.
I want to share a picture of my first button too, is there a thread for that?
Thanks so much so far for all the great help you all!
Martijn.
I cannot wait to see you show that gold off in the gallery section, it is looking very good.
kernels
Well-known member
For what it's worth, I raise the ph to 2 using Soda Ash, then later on precipitate the Iron Hydroxide with Magnesium oxide. From reading above, it sounds like you are doing the opposite. I'm pretty sure my way is what was recommended by 4Metals years ago. My Iron Hydroxide settles very well this way.
Martijn
Well-known member
No, i tried just that. Raising with soda ash to Ph2, but it did not go up. Adding more did not do anything. Hence my first post. :wink: https://goldrefiningforum.com/phpBB3/viewtopic.php?f=47&t=1300&start=90#p300206
I think there's to much acid from emptying the whole cell of sulfuric in it combined with the low outside temp. thats keeping the saturaton point of soda low? (Assumption)
It just didn't dissolve or react with the acid. And sat on the bottom.
So now i'm trying to boil a small part of the solution down to make some copperas as Butcher suggested. The soda ash dropped out, followed by some, (i think) long neelde like lead crystals. More testing and experimenting needed. They're drying now. Beautiful and also probably very toxic... must read MSDS next. :shock:
I read your post about using magnesium oxide and bought some... it took the remaining solution to Ph5 very easy by adding half a cup, slowly and stirring to avoid 'boiling over' Left some hard chuky grains and a layer of light brown mud which settled fast.
Great idea Kernels, thanks
Will dry the residue and see if there's any use for the mud. Further raising to Ph11 to push out hydroxides can be done with NaOH, right?
I will test small amounts with different alkali like lye and soda to see what happens.
Martijn.
I think there's to much acid from emptying the whole cell of sulfuric in it combined with the low outside temp. thats keeping the saturaton point of soda low? (Assumption)
It just didn't dissolve or react with the acid. And sat on the bottom.
So now i'm trying to boil a small part of the solution down to make some copperas as Butcher suggested. The soda ash dropped out, followed by some, (i think) long neelde like lead crystals. More testing and experimenting needed. They're drying now. Beautiful and also probably very toxic... must read MSDS next. :shock:
I read your post about using magnesium oxide and bought some... it took the remaining solution to Ph5 very easy by adding half a cup, slowly and stirring to avoid 'boiling over' Left some hard chuky grains and a layer of light brown mud which settled fast.
Great idea Kernels, thanks
Will dry the residue and see if there's any use for the mud. Further raising to Ph11 to push out hydroxides can be done with NaOH, right?
I will test small amounts with different alkali like lye and soda to see what happens.
Martijn.
Martijn
Well-known member
Butcher, i was reading your reply about the white layer on stockpot copper:
https://goldrefiningforum.com/phpBB3/viewtopic.php?f=60&t=26029&p=276363&hilit=White+layer+on+copper+in+stockpot#p276323
Because i have that too.
In it you say lead chloride will form long crystals, do you think mine in the picture are that? Some one else his post said the same about lead nitrate, i can't find that one anymore. Could not find pics of it here on the forum. And google didn not yield much info.
Martijn.
https://goldrefiningforum.com/phpBB3/viewtopic.php?f=60&t=26029&p=276363&hilit=White+layer+on+copper+in+stockpot#p276323
Because i have that too.
In it you say lead chloride will form long crystals, do you think mine in the picture are that? Some one else his post said the same about lead nitrate, i can't find that one anymore. Could not find pics of it here on the forum. And google didn not yield much info.
Martijn.
Martijn,
I am not sure which picture you are referring to.
Where did you introduce a chloride or nitrate?
You very likely had lead sulfates, and now some lead carbonates.
It is hard for me to follow what you are doing without going back and reading again through what all you have already posted and what we have already discussed. my memory is not good.
Many metal different metal salts make crystals some grow in certain shapes, minerals in rocks will also form crystals, these shapes can be used as clues to what a mineral or metal salt maybe, although a helpful tool but only when used with other tools, tests, or clues to identify the mineral or salt.
I am not sure which picture you are referring to.
Where did you introduce a chloride or nitrate?
You very likely had lead sulfates, and now some lead carbonates.
It is hard for me to follow what you are doing without going back and reading again through what all you have already posted and what we have already discussed. my memory is not good.
Many metal different metal salts make crystals some grow in certain shapes, minerals in rocks will also form crystals, these shapes can be used as clues to what a mineral or metal salt maybe, although a helpful tool but only when used with other tools, tests, or clues to identify the mineral or salt.
kernels
Well-known member
That is some odd behaviour, I find it usually very easy to raise the pH to 2 by Soda Ash, ambient temperature around 20 degrees C. Magnesium Oxide is very slow to show a pH change in my experience, so I look at the solution colour when precipitating Iron Hydroxide, rather than measure the pH.
Martijn
Well-known member
butcher said:
Butcher, i'm referring to the third picture from top on this page, looking at the flask from the bottom. the green is the liquid Ferrous sulfate, after filtering out soda and settling over night (temp. was -1Celcius)
The chlorides and nitrates came from adding spent nitric, HCL washes and AR solution to the stock pot which held the sulfuric waste already, did not separate different waste streams. And i precipitated some AgCl traces from the spent nitric with HCL too. May even added some acquaintance test tube contents to it, not sure anymore. The nitric is likely to hold some lead/tin, same for the AR after SMB precipitaion.
I will post a better picture of the crystals after drying.
And i will do some Acquaint. tests with lead on HCL, Nitric and Sulfuric, allthough lead will not go in solution in sulfuric I think. No need for a fast answer, i will perform some tests first.
Martijn.
