about platinum precipitation!

[orvi]

Work with PGMs start to be PITA when you begin to dilute them. As no separation by standard means aside cementation is quantitative (mainly with platinum and rhodium).

Hydrometallurgical treatment of cats has it´s own negatives. Generally, concentration of values is my first incentive, since working with 100 ml is completely different than 10 L. I used iron plate, hanging in the bucket with plastic string. You can as well use zinc, but iron is enviromentally benign and cheap. Of course, it took more time, but it is finite and easy to do. You will usually obtain relatively compact cement, which comes down from iron in flakes upon scratching. If cementation stops, add fresh HCL - this will help to kickstart it.

You will obtain a bit of cemented residue, which is then easy to continue with. Best option is to macerate it for some time in warm HCL in order to dissolve unwanted elements such as Fe, Co and Ni/Cr. Then you can directly melt it.

 

[samuelbaldwin010]

Is the pool shock a liquid?

Yes. It's liquid. 10% sodium hypochlorite.

 

[Yggdrasil]

Yes. It's liquid. 10% sodium hypochlorite.

That strong Hypochlorite decomposes fast and needs to be stored cold.

 

[samuelbaldwin010]

I recommend you to stop what you are doing, you do not have the proper tools to do this.
PGM salts are very toxic and most professional refiners do not even touch it.
So you should stop and store your stuff in closed containers,
at least until you have acquired proper glassware, safety gear and protective systems to contain your mess.
Have you read Hokes and the safety sections in the forum?

I appreciate your concern. Yes I know that the pgms in salt form are extremely toxic and direct contact with them should be avoided at all cost, whenever possible.
What equipment is it exactly you believe that I am lacking in?
In terms of safety gear, I am working outside, either always being up wind of fumes, with a respirator mask on for extra protection, safety glasses on, and I have on very thick yellow rubber gloves.
I am aware that I want to minimize my chances of exposure in every possible way.

All of that being said, I am a hands on (or in this case more like hands off) type of learner, so I need the experience and the failure, too, are all part of the learning process. I feel like most of the safety revolves around common sense things luckily.

But I really do respect and appreciate your advice, I need a little more clarification on exactly what your concern is for me primarily

 

[samuelbaldwin010]

That strong Hypochlorite decomposes fast and needs to be stored cold.

Stored cold as in slightly below room temperature and not above like 100 degrees Fahrenheit?

 

[samuelbaldwin010]

As for reading Hoke, I already have read through it once and now i am reading through it again to hopefully absorb what I didn't in the first go.

There is a LOT of information there to take in from that book. I doubt anyone would retain all of it just reading it once, atleast I know honestly I didn't.

 

[samuelbaldwin010]

Work with PGMs start to be PITA when you begin to dilute them. As no separation by standard means aside cementation is quantitative (mainly with platinum and rhodium).

Hydrometallurgical treatment of cats has it´s own negatives. Generally, concentration of values is my first incentive, since working with 100 ml is completely different than 10 L. I used iron plate, hanging in the bucket with plastic string. You can as well use zinc, but iron is enviromentally benign and cheap. Of course, it took more time, but it is finite and easy to do. You will usually obtain relatively compact cement, which comes down from iron in flakes upon scratching. If cementation stops, add fresh HCL - this will help to kickstart it.

You will obtain a bit of cemented residue, which is then easy to continue with. Best option is to macerate it for some time in warm HCL in order to dissolve unwanted elements such as Fe, Co and Ni/Cr. Then you can directly melt it.

Thanks for your advice. Just so I understand correctly what you're proposing that I do, you are reccomending that I basically just cut my losses and cement out whatever values are left with iron, and start all over again with black mixed pgm powders? Or are you proposing that I just cement everything out and melt the mixed powders together?

I may just do that if I cannot get everything figured out but I must warn you, mama didn't raise no quitter ,
Also I have been successful at precipitating the red palladium salt from my hcl and bleach solution, so thats encouraging, it's just the aqua regia batch that's giving me the trouble.

Idk what it is but it's not precipitating anything after I added the ammonium chloride and it still tests positive for platinum with stannous.
So, my thoughts are as follows; my mistake here I think, is maybe there is still unused nitric that I haven't sucessfully expelled out of the aqua regia solution, since I didn't denox with sulfamic acid or anything, i just tried evaporating to syrup and rehydrate with more hcl and water as per hoke, but i think that maybe i failed to do so adequately and that's what is preventing the ammonium chloride from working.

Would that be a fair assessment or am I going way off the reservation here?

 

[Yggdrasil]

Stored cold as in slightly below room temperature and not above like 100 degrees Fahrenheit?

It should be stored in slightly above freezing like in a refrigerator. around 4-8 Centigrade.
Or you can use Calcium Hypochlorite in stead, it is a chemically stable powder.
Another option is pool tablets.

 

[Christian333]

I appreciate your concern. Yes I know that the pgms in salt form are extremely toxic and direct contact with them should be avoided at all cost, whenever possible.
What equipment is it exactly you believe that I am lacking in?
In terms of safety gear, I am working outside, either always being up wind of fumes, with a respirator mask on for extra protection, safety glasses on, and I have on very thick yellow rubber gloves.
I am aware that I want to minimize my chances of exposure in every possible way.

All of that being said, I am a hands on (or in this case more like hands off) type of learner, so I need the experience and the failure, too, are all part of the learning process. I feel like most of the safety revolves around common sense things luckily.

But I really do respect and appreciate your advice, I need a little more clarification on exactly what your concern is for me primarily

Are you utilizing a catch pan, one that is large enough to contain a boil over?

Janie

 

[samuelbaldwin010]

It should be stored in slightly above freezing like in a refrigerator. around 4-8 Centigrade.
Or you can use Calcium Hypochlorite in stead, it is a chemically stable powder.
Another option is pool tablets.

Ah. I see. In the fridge it goes then. But, I did check out the calcium hypochlorite that you are referring to but , in my opinion, it was just wayyyyyy tooo expensive. I think it was like $60 just for a little tub of it and the liquid pool shock (the 10% sodium hypochlorite) was only like around $10 for a gallon if I remember correctly...

I am not made outta money . So I try wherever I can to save a few bucks, all as long as it doesn't compromise my, or other's safety around me. That's why I will do things like learn how to (safely) make my own concentrated fuming nitric acid via distillation of nitrate salts and concentrated sulfuric acid, cause I am sure most of us can agree, that stuff is insanely expensive and it's so easy to synthesize and do it relatively cheaply and easy, and also, more over, safely.

 

[samuelbaldwin010]

But also, I was curious, first though, forgive my ignorance as I am just learning still, will the calcium hypochlorite leave any calcium residue after the desired reaction has been achieved?

I only ask because I have notice some things that have calcium in them tend to leave an annoying and hard to easily get rid of residue. Particularly when using calcium ammonium nitrate fertilizer to make nitric, since normally it would be alot easier to just add another nitrate salt such as sodium nitrate or potassium nitrate directly with the sulfuric acid to get nitric instead of having the only option to be distillation as with calcium ammonium nitrate.

 

[samuelbaldwin010]

Are you utilizing a catch pan, one that is large enough to contain a boil over?

Janie

Ah. Yes, usually I do have one, but I had recently broke it because I accidentally dropped it, so I need to go and buy another crock somewhere.

While we are kind of on this topic about lab equipment and PPE does anyone know of anywhere or even anyone of whom I could possibly buy a distillation flask or possibly even some bigger beakers, and such for as least as I can get away with?

As I was saying before, if I can save a few dollars anywhere, I am willing to at least check it out. And I figure maybe someone will take pity on this noob?

Can't hurt to ask right?
Thanks in advance,
-Samuel

 

[Yggdrasil]

But also, I was curious, first though, forgive my ignorance as I am just learning still, will the calcium hypochlorite leave any calcium residue after the desired reaction has been achieved?

I only ask because I have notice some things that have calcium in them tend to leave an annoying and hard to easily get rid of residue. Particularly when using calcium ammonium nitrate fertilizer to make nitric, since normally it would be alot easier to just add another nitrate salt such as sodium nitrate or potassium nitrate directly with the sulfuric acid to get nitric instead of having the only option to be distillation as with calcium ammonium nitrate.

Calcium Hypochlorite is normally much cheaper than Sodium Hypochlorite,
and it holds for years.
And as long as there’s no Sulfuric or Sulfates it should stay in solution.
Calcium Nitrate can be preferential when making Nitric, since it creates Gypsum which can be filtered out completely.

 

[Golddigger76]

Walmart sells 1 gallon jug of sodium hyporchlorite for swimming pool treatment for $10.99

 

[samuelbaldwin010]

Calcium Hypochlorite is normally much cheaper than Sodium Hypochlorite,
and it holds for years.
And as long as there’s no Sulfuric or Sulfates it should stay in solution.
Calcium Nitrate can be preferential when making Nitric, since it creates Gypsum which can be filtered out completely.

Yes, I totally understand and agree with you. However, I just was buying the sodium hypochlorite on an as needed basis. So, it wasn't really a big problem with it sitting around idle for any prolonged amount of time.

But, I will certainly keep that calcium hypochlorite in mind as an option in the future. One little question I had was though: so, if there are any sulfates or sulfuric acid present, that will prevent the calcium from staying in solution?

Interesting fact. You learn something new everyday. And yes, I did realize that using the calcium ammonium nitrate would make the gypsum leftover as a byproduct and I did consider filtering it out but,

I could not find the patience to wait for it to filter through as I imagine it would be painstakingly slow. And u also I don't think that the paper filter would make it through the abuse from the concentrated sulfuric acid. What would you suggest as a way around that? What would work as a good alternative? I don't think cotton would work, as it too, would be destroyed by the acid.

Do you think that I would be able to use plain water to somehow separate just the ammonium nitrate and filter out the calcium somehow, then make the nitric with the watery solution and excluding the calcium or is this not possible?

 

[samuelbaldwin010]

Walmart sells 1 gallon jug of sodium hyporchlorite for swimming pool treatment for $10.99

Yeah, I think that is about how much I paid at ace hardware. But I live in portland, Oregon, where we no longer have any Walmart stores. I think I would have to buy it from the website and then wait for delivery.

Do you know if that sodium hypochlorite had a higher percentage than 10% like the one I was already getting from ace hardware?

 

[Erceg]

And u also I don't think that the paper filter would make it through the abuse from the concentrated sulfuric acid. What would you suggest as a way around that? What would work as a good alternative? I don't think cotton would work, as it too, would be destroyed by the acid.

There are fibreglass filters. I know about Whatman ones, but they cost a bit more. Also you can speed up filtration using Büchner filtration. You kill two flies with one hit with that; your impatience and giving sulfurick less time to eat at paper. But I would recommend fibreglass filters (you might still be forced to use vacuum).

 

[samuelbaldwin010]

There are fibreglass filters. I know about Whatman ones, but they cost a bit more. Also you can speed up filtration using Büchner filtration. You kill two flies with one hit with that; your impatience and giving sulfurick less time to eat at paper. But I would recommend fibreglass filters (you might still be forced to use vacuum).

Thank you for your prompt response and advice. Do you know roughly how much that would all cost?
I would love to have all of those items, but unfortunately, I doubt that I could afford it financially.
I am broke as a joke ( and a bad joke at that!), however, as soon as I can afford to, I would definitely like to look into acquiring that stuff, just don't know when that will be.

Great suggestion though! I didn't even think about it. And I know that I am probably derailing this thread with my million seemingly unrelated questions that have little to do with the topic. So, I do very much apologize for that.

One last question though: whenever you use a Charmin plug, as I have heard it referred to, for the finely divided precious metals, what do you then do with it? Dry it out? Put it in with old filter papers? Burn it and then try to wash out all the carbon?

I must know.

Thanks for answering in advance.

-Samuel

 

[Yggdrasil]

Thank you for your prompt response and advice. Do you know roughly how much that would all cost?
I would love to have all of those items, but unfortunately, I doubt that I could afford it financially.
I am broke as a joke ( and a bad joke at that!), however, as soon as I can afford to, I would definitely like to look into acquiring that stuff, just don't know when that will be.

Great suggestion though! I didn't even think about it. And I know that I am probably derailing this thread with my million seemingly unrelated questions that have little to do with the topic. So, I do very much apologize for that.

One last question though: whenever you use a Charmin plug, as I have heard it referred to, for the finely divided precious metals, what do you then do with it? Dry it out? Put it in with old filter papers? Burn it and then try to wash out all the carbon?

I must know.

Thanks for answering in advance.

-Samuel

That depends on which fraction holds your valuables.
If it is in the liquid, the plug is waste.
If opposite you can dissolve the remnants in a new leach.

 

[Erceg]

Can't tell you the price. Different countries, different stores, different prices. Google what stores have those and what kinds (how fine particles filter can filter). Just remember, more fine paper is (can catch smaller particles) slower filtration is. Sometimes it won't go without vacuum.