Cementing copper.

[gaurav_347]

Hello All,

We have around 12 tonnes of copper nitrate solution kept with us. We are looking to recover copper from it. The assay report shows 62 percent of copper in this waste solution. What will be the most economical method to cement out copper from this. We have asked local refineries and they are quoting a very low price (50 cents per kg). With the copper prices skyrocketing we are thinking that it would be better to recover the copper in house even if it takes us time we are ok with it since labour is pretty cheap where I live. We have recovered copper on a small scale before with iron but are unsure what will be the most reliable method to do this on a big scale. Would really appreciate all the help that you give.

I hope you all are keeping yourselves and your families safe during these tough times.

Regards
Gaurav

 

[kurtak]

Hello All,

We have around 12 tonnes of copper nitrate solution kept with us.

That is a LOT of copper nitrate --- but it doesn't really tell us how much that is in gallons/liters --- could you tell us how much a liter weighs :?:

Please answer that

I ask because when I shut my refining operation down I had something like 800 gallons (in 55 gallon drums) of copper containing solutions (both nitric & AR solutions) that I needed to clean up (remove the copper from)

I started out using large pieces of iron in a barrel with a large aquarium bubbler but that was taking a long time --- so I went & bought some steel wool (in bulk - couple hundred pounds)

I bought the steel wool from this company

:arrow: https://steelwooldirect.com/

I bought their steel wool "trimmings" --- grade #0

:arrow: https://shop.steelwooldirect.com/product/25-lbs-steel-wool-trimmings-grade-0-1-2-or-3/

What will be the most economical method to cement out copper from this.

I can't say how economical it was because I used both methods - barrel/iron/bubbler - & barrels with steel wool

What I can tell you is the steel wool was 3 - 4 times faster cementing the copper then the bubbler method - I was more interested in getting the job done so I liked the steel wool for the speed of getting the job done

The company I bought the wool from is a USA company so the price is rather high (though I did get a price break for buying more then a hundred pounds)

However I see you are in India - so you could likely get it for a better price on alibaba

If you decide to go with the steel wool method there are a couple things you need to know - which I can explain if you decide to go that way

And of course the other method would be to set up for electro winning

Kurt

 

[kurtak]

Just out of curiosity - how/why are you producing so much copper nitrate

Are you processing a lot of silver (then cementing the silver with copper)

or dissolving a lot of copper to recover gold plating

some of both

or something else

Kurt

 

[justinhcase]

Hello All,

We have around 12 tonnes of copper nitrate solution kept with us.

That is a LOT of copper nitrate --- but it doesn't really tell us how much that is in gallons/liters --- could you tell us how much a liter weighs :?:

Please answer that

I ask because when I shut my refining operation down I had something like 800 gallons (in 55 gallon drums) of copper containing solutions (both nitric & AR solutions) that I needed to clean up (remove the copper from)

I started out using large pieces of iron in a barrel with a large aquarium bubbler but that was taking a long time --- so I went & bought some steel wool (in bulk - couple hundred pounds)

I bought the steel wool from this company

:arrow: https://steelwooldirect.com/

I bought their steel wool "trimmings" --- grade #0

:arrow: https://shop.steelwooldirect.com/product/25-lbs-steel-wool-trimmings-grade-0-1-2-or-3/

What will be the most economical method to cement out copper from this.

I can't say how economical it was because I used both methods - barrel/iron/bubbler - & barrels with steel wool

What I can tell you is the steel wool was 3 - 4 times faster cementing the copper then the bubbler method - I was more interested in getting the job done so I liked the steel wool for the speed of getting the job done

The company I bought the wool from is a USA company so the price is rather high (though I did get a price break for buying more then a hundred pounds)

However I see you are in India - so you could likely get it for a better price on alibaba

If you decide to go with the steel wool method there are a couple things you need to know - which I can explain if you decide to go that way

And of course the other method would be to set up for electro winning

Kurt

Why use steel wool?
I just use scrap iron as it is free.
Admittedly I do not use it for straight Copper nitrate, but a mix of metal salts from my waste.
I also add plated ferrous such screws and chromed parts as not only the copper is of value but so are all the other nice base metals such as Nickel chrome and tin.
I have not smelted any of my cement from sacrificial iron yet, but I am hoping for a good yield of mixed alloy.
No idea how much I have collect so far, but I am unable to move the storage bin any more even with help.

 

[gaurav_347]

Just out of curiosity - how/why are you producing so much copper nitrate

Are you processing a lot of silver (then cementing the silver with copper)

or dissolving a lot of copper to recover gold plating

some of both

or something else

Kurt

So basically I posted the above query on behalf of my uncle. They are in the business of manufacturing bathroom fittings like faucets ,taps , etc. ( mostly everything that you see in your bathroom) one of their process involves electroplating. They did the assay today and the results are as follows CU 66.6% NICKEL 21.4% . Also the material is in a salt form and not liquid form. I have attached a picture for better understanding.

what would be the best possible way to go about processing such material?

Regards,
Gaurav

 

[justinhcase]

Before you decide what to do, see what you can sell and how much you will be offered for each.
You can try and find a copper refiner who would take it as is, of one that would take the cemented metals.
We have no way of telling who you have access to.
Take a good sample, dissolve in distilled water and drop some scrap iron into it. Leave it for a day or two and see what you have.

 

[FrugalRefiner]

They did the assay today and the results are as follows CU 66.6% NICKEL 21.4% .

What is the other 22%?

Dave

 

[butcher]

Generally roasting the copper ore to convert the copper salts to oxides, dissolving these in acid (such as H2SO4) to form an electrolyte to recover copper from, or through smelting of the copper oxides reducing them to metal using flux and heat. and times where roasting, smelting and electrolysis are all used to get a higher quality copper from the ore (or salt of copper).

 

[g_axelsson]

That doesn't look like a nitrate salt to me. More like oxides or hydroxides together with some iron.

Are you sure that it hasn't been calcined, heated strongly to drive off water and at the same time breaking down the nitrate?

Copper nitrate is very soluble in water and gives a deep blue solution. It is also very heat sensitive and decomposes at 170 C into NOx-fumes and copper oxide.

Göran

 

[kurtak]

Hello All,

We have around 12 tonnes of copper nitrate solution kept with us. We are looking to recover copper from it. The assay report shows 62 percent of copper in this waste solution.

Gaurav

Per the underlined - I am a bit confused - in your first post you said you have a LOT of copper nitrate solution which you want to know the best way to cement the copper from the solution

But then yesterday you posted (along with a pic of what you have)

Also the material is in a salt form and not liquid form.

So - are you wanting to cement copper from an actual solution - or are you wanting to deal with the product shown in yesterdays posted picture :?:

Goran posted -----------

That doesn't look like a nitrate salt to me. More like oxides or hydroxides

I agree --- though we could be wrong

How did you come by the product in the picture :?:

Was it simply evaporated down to a solid from the original solution :?:

Was it already cemented from the original solution :?:

Was it dropped from the original solution with a hydroxide or carbonate(then dried) :?:

If you are trying to recover the copper from what you showed in yesterdays pic --- the we need to know details of what that product is & how you got to that as a product

Kurt

 

[kurtak]

Why use steel wool?

As I said yesterday - speed (time) - when you start producing "large" amounts of waste time matters

steel wool will drop your copper 3 - 4 times faster then large pieces of iron with a bubbler in a 55 gallon drum of solution

so cheaper is not always better - if/when time is also an issue --- or as the old saying goes - time is money

Kurt

 

[justinhcase]

Why use steel wool?

As I said yesterday - speed (time) - when you start producing "large" amounts of waste time matters

steel wool will drop your copper 3 - 4 times faster then large pieces of iron with a bubbler in a 55 gallon drum of solution

so cheaper is not always better - if/when time is also an issue --- or as the old saying goes - time is money

Kurt

Time and effort, cementing and settling tanks are two things that should take their time.
Larger sacrificial bars are slower than powder and shavings, but leave much less contamination than smaller particles.
I have had a palladium cementation with zinc running for weeks which is an extreme example, iron being much more reactive will be through in a week or two at the most.
A good waste treatment policy should have in place a surplus of storage for the task, so each stage can be addressed properly.
They evidently have absolutely no system in place so must start from scratch to put together as efficient a system as possible, so they do not build up such a backlog again.
They will want a set-up that can process their normal weekly output but over built, so they can work their way through the stored backlog.
Space and time over material cost.
It will be interesting to see which rout they decide to follow.

 

[kurtak]

Time and effort, cementing and settling tanks are two things that should take their time.
Larger sacrificial bars are slower than powder and shavings, but leave much less contamination than smaller particles.
I have had a palladium cementation with zinc running for weeks which is an extreme example, iron being much more reactive will be through in a week or two at the most.

Justin - I am sorry but there is just so much wrong with what you have posted here I don't even know where to start

But lets start here

I have had a palladium cementation with zinc running for weeks which is an extreme example, iron being much more reactive will be through in a week or two at the most.

Per the underlined --- Iron is NOT more reactive then zinc - zinc is MUCH MORE reactive then iron

However - when it comes to the reactive series - you also need to understand how different acids react with different metals

Example; - aluminum is even more reactive then zinc - however (as reactive as aluminum is) it does not react well with nitric acid (little to no reaction) - but is VERY reactive to HCl

Zinc --- although it will react with nitric - it (some what like aluminum) does not react well with nitric though more so then aluminum - but again VERY reactive with HCl

On the other hand - copper - though it is "much less" reactive then zinc or aluminum - copper reacts very well to nitric - but does not react to HCl

Therefore - when cementing silver &/or Pd from a nitric solution copper should be what you use for a fast clean silver or Pd cement --- where as aluminum wont work & zinc will be problematic

Copper should ALWAYS be your FIRST metal of choice for cementing PMs from solution because it (normally) wont cement other metals above it in the reactive series

Why are you using zinc &/or iron - when you should be using copper :?:

If you are having trouble cementing Pd with copper - I can help you to solve any such problem you may be having cementing Pd with copper (there are a few tricks you "need" to know when cementing Pd with copper)

That is all I have time for posting today - however as a quick reference -------

You said - "Time and effort, cementing and settling tanks are two things that should take their time."

Just flat out not true :!:

You said - "Larger sacrificial bars are slower than powder and shavings, but leave much less contamination than smaller particles."

Just flat out not true :!:

If you can't cement your PMs from their solutions in a day or less (2 days at the most) & get a relatively clean product - then you are doing something wrong in your cementing process

Lets figure out what the problem is - & how to fix it

Kurt

 

[justinhcase]

Yes I miss spoke about the zinc, it being so good at resisting corrosion by virtue of its pacifying ability to make one think it is more robust than it is, most of my work shop roof is steel coated with zinc to stop the iron from rusting.
And I used zinc in this cementation as it was advised in a good number of papers.
My observations about contamination and the size of sacrificial metal come from running silver, I have found melting my scrap copper to large bars reduced the amount of contamination left behind when I came to wash the cemented silver when compared to small bits of wire and pipe. I reasoned that the larger bars would not degrade to small undigested bit in the cement and are easier to remove in one piece as they are drilled with a stainless steel hook.
And time is probably my most valuable asset.
I am completely run into the ground seeing clients and working on a property development besides my metal refining.
How I managed to work as a security officer as well for all those years I will never know.
But because of this I take a bit of a more glacial approach to my metals.
If something is not running through a filter, I leave it for a day or two to work its way through by its self, or avoid vacuum filtration completely if I think it will be problematic and just use a large filter paper and funnel.
The same with cementing, I have found silver left in solution after several days of cementation, So I let the liquor dictate the time and simply leave it until it tests clean.
I have taken the same approach with the Pd, it has mostly cemented, but I did get a slight DMG yellow positive, so I did not worry about it. I simply left it another week or two it should test clean soon.
It has taken me seven years to build up that much Pd, so another few weeks make no difference.
Thank goodness gold is so much easier to turn over.

 

[MicheleM]

Hello Kurtak,
I have no experience in palladium recovery and refining , but I am curious and I would like to know what are the tricks you was talking about cementing palladium with copper, could you explain more about that? Thank you very much

 

[conglioa]

Just out of curiosity - how/why are you producing so much copper nitrate

Are you processing a lot of silver (then cementing the silver with copper)

or dissolving a lot of copper to recover gold plating

some of both

or something else

Kurt

So basically I posted the above query on behalf of my uncle. They are in the business of manufacturing bathroom fittings like faucets ,taps , etc. ( mostly everything that you see in your bathroom) one of their process involves electroplating. They did the assay today and the results are as follows CU 66.6% NICKEL 21.4% . Also the material is in a salt form and not liquid form. I have attached a picture for better understanding.

what would be the best possible way to go about processing such material?

Regards,
Gaurav

Hello
If your ingredients are the same as in the picture you posted and have 66% copper, not nitrate solution then I think you should grind them, then oxidize to convert them to oxide and next You can easily dissolve them into 10% sulfuric acid (1/3 liquid solid ratio) under aeration. It only takes a few hours to dissolve. Once you have copper sulfate solution, just let them settle and take the clear solution, then electrolyze to recover pure copper. Hope this helps you.

 

[Goldenrod757]

Time and effort, cementing and settling tanks are two things that should take their time.
Larger sacrificial bars are slower than powder and shavings, but leave much less contamination than smaller particles.
I have had a palladium cementation with zinc running for weeks which is an extreme example, iron being much more reactive will be through in a week or two at the most.

Justin - I am sorry but there is just so much wrong with what you have posted here I don't even know where to start

But lets start here

I have had a palladium cementation with zinc running for weeks which is an extreme example, iron being much more reactive will be through in a week or two at the most.

Per the underlined --- Iron is NOT more reactive then zinc - zinc is MUCH MORE reactive then iron

However - when it comes to the reactive series - you also need to understand how different acids react with different metals

Example; - aluminum is even more reactive then zinc - however (as reactive as aluminum is) it does not react well with nitric acid (little to no reaction) - but is VERY reactive to HCl

Zinc --- although it will react with nitric - it (some what like aluminum) does not react well with nitric though more so then aluminum - but again VERY reactive with HCl

On the other hand - copper - though it is "much less" reactive then zinc or aluminum - copper reacts very well to nitric - but does not react to HCl

Therefore - when cementing silver &/or Pd from a nitric solution copper should be what you use for a fast clean silver or Pd cement --- where as aluminum wont work & zinc will be problematic

Copper should ALWAYS be your FIRST metal of choice for cementing PMs from solution because it (normally) wont cement other metals above it in the reactive series

Why are you using zinc &/or iron - when you should be using copper :?:

If you are having trouble cementing Pd with copper - I can help you to solve any such problem you may be having cementing Pd with copper (there are a few tricks you "need" to know when cementing Pd with copper)

That is all I have time for posting today - however as a quick reference -------

You said - "Time and effort, cementing and settling tanks are two things that should take their time."

Just flat out not true :!:

You said - "Larger sacrificial bars are slower than powder and shavings, but leave much less contamination than smaller particles."

Just flat out not true :!:

If you can't cement your PMs from their solutions in a day or less (2 days at the most) & get a relatively clean product - then you are doing something wrong in your cementing process

Lets figure out what the problem is - & how to fix it

Kurt

Im just so very busy. I feel very luck to have come across this informative response. Thanks!

 

[timetoorefine]

Hey Kurt, I am with Michele's above post regards to dropping Pd from my waste nitric. Have been running gold filled for quite awhile and have 6+ drums of mainly copper nitrate, but a considerable amount of white gold was processed along with everything else. I imagine selective cementation may be most appropriate, but up until now had intended to simply hang iron plates and agitate. Have read some papers on spent nitric treatments, and bringing the pH up to 1.5 looks to improve speed and efficiency. Nevertheless, the bottom line for recovering values points clearly to the palladium component, as market price is approaching $3K/ozt. Not sure about the economics of digesting copper to accomplish this task, even though Cu can be recovered in subsequent stages. Anyway if you could offer some guidelines for such work, I would greatly appreciate!

John