NEC telecomm box components

[kjavanb123]

It is not lost ....is in your melting dish....if you can provide a picture of your melting dish (I'm guessing covered in black...because you did not reach the temperature for melting Pd....and that I say only looking of the final product.... it is "frozen")

Hi

I dont have the pic of the melting dish but what u see in the first two photos of Pd which was rolled to inspect any cracks which there was none which is indication of purity.

If you refer to third and foruth pics as "frozen" that is silver bead

 

[kjavanb123]

Hi everyone

As promised I have finished processing the entire contacts removed from a NEC telecomm box components and recovered Ag, Au, Pd and Pt

The final powders will be melting today and will post them tonight.

Here are some pictures of contacts removed manually from different components of this telecomm box, total weight is 189 grams.









Processing continued next post

 

[kjavanb123]

First

All components were dissolved in hot dilute nitric acid, it took almost 500 ml of nitric acidto completely dissolve Pd, Ag and other base metals.

There were gold and platinum foils plus some tin nitrate paste in the beaker.

Here is the main nitrate solution with Pd G and all base metals


The residue not dissolved in nitric acid containing tin nitrate, gold and platinum. Gold is visible with naked eyes

 

[kjavanb123]

First thing addition of hcl to drop silver as silver chloride, then filtering it, wash it with hot water till the passing solution is negative for any Pd.


Cementing with zinc powder washing the silver powder till pH is 7, drying.








Total weight for dried silver powder is 3.90 grams

 

[kjavanb123]

Ok now going at the main precious metals used in all these contacts, Palladium.


Checked with stannous and got this dark brown result


As it has been discussed in forum, there are at3 main methods of dropping Pd from a solution, which means cemeting on copper, or dropping with zinc powder, and for small or lab size using DMG. Not to mention ammonium salt follow by ammonia wash adding hcl

I have access to a reliable yet inexpensive DMG source so I can use that for a quicker method of recovery for Pd.

I prepared a DMG solution based on the guidelines provided by R.I.P freechemists (4g NaOH, 100 ml hot water, 5.81g DMG)

Added 100ml of DMG solution to Pd solution and got the deep yellow salt.


DMG addition repeated till stannous showed negative for Pd.

Here are some photos of stannous testing on passing solution after first, and second DMG solution addition.

 

[kjavanb123]

The yellow salt for each step was converted using zinc powder and hcl, and black Pd powder produced from each step was washed throughly till pH showed 7.

Here is the last Pd drop added to the previous ones to be dried.

Here is the dried Pd powder from entire lot, (not including 2.23 grams Pd which was melted from 22 gram lot 1).


Total dried weight for Pd black is 8.28 grams.

 

[kjavanb123]

Here is the part that I have never experienced before and that is dealing with a scrap that contained both gold and platinum.

Here is AR solution of dissolving tin nitrate gold and platinum.




Here is stannous chloride test result it shows both purpule and orange.

 

[kjavanb123]

Diluted the AR gold platinum solution,


Added SMB


After 2 hours, gold had precipitated


This is the gold powder hadnt gone through 3 washes with distilled water, ammonia and hcl yet


Gold powder after washes and dried weighs 0.17 gram.

 

[kjavanb123]

After gold was dropped, solution was filtered and tested with stannous and showed weak Pt presence.


I added zinc powder to the above solution, and this happened,


During that reaction little of sulfur gas could be smelted. I filtered everything and checked the filtered solution there was no sign of Pt.


I dissolved everything filtered in AR


All that white yellowish powder dissolved in AR and tested positive for platinum.


Next post

 

[kjavanb123]

There was this piece left which everytime I boiled in AR stannous showed positive for Platinum but this wouldnt dissolve.


So I dropped the Pt black using zinc powder from the solution and will melt the powder and thatn unknown piece all together

 

[kjavanb123]

All

Finally finished melting the powders into metal beads

Here is palladium, 8.23 grams Pd black powder plus 2.23 grams of Pd metal,




It weighed 9.25 grams, after rolling it seemed like it cracked as can be seen here



After second melting it weighed 8.50 grams but I bought a new melting dish and return to the jewler in evening to re melt it again.

Here is for John who was interested in seeing the melting dish after second melting of 9.25 gram Pd button.

 

[kjavanb123]

Silver beads from entire contacts including the bead from last lot 1,




Here is the platinum from entire lot processing
Weighs 0.390 gram



Gold and refined Pd will be posted in few hours

 

[kjavanb123]

Hi everyone

Since the Pd bead was impure, had to dissolve it in nitric acid.

This impure Pd bead weighed 8.050 grams.

Here is a photo of back and front, you notice a yellowish tint in the first picture that seemed like gold.



So I decided to dissolve the bead in near boiling dilute nitric acid. It took 2 hours amd 50 minutes for 8.05 grams of Pd dissolve completely.



And gold which did not dissolve in nitric remained


Gold powder cleaned up by few hot water washes


More next post

 

[kjavanb123]

Since I had used a lot of nitric acid to dissolve Pd bead and didnt have DMG or ammonia salt to drop Pd, I added hcl to solution till it was 800 ml of burgandy Pd solution

Then I brought the solution to near boil, added small amounts of sulfamic acid to expell too much nitric which was used.

Almost took me 1 hour and 40 minutes till all the excessive nitric was gone.

Transfered the Pd solution to a bigger bucket, and added zinc powder to drop the Pd black as it can be seen here


To this


Washed the Pd black till pH was 7, dried it


Continued next

 

[kjavanb123]

Finally melted the Pd black powder and got this lovely Pd bead.






I like to thank the forum and its great members some of whom are not with us anymore like freechemist to give me the initial understanding about all of these.

Lastly the photos of silver and melted gold next

 

[kjavanb123]

Gold 0.210 gram


Silver cleaned up




Thanks and best regards

 

[Yggdrasil]

Hi Kjavan!
I just revisited this thread, and your silver cementing just puzzled me.

You said

Silver chloride was filtered and washed throughly with hot water till the solution passed the filtee turn clear and stannous test showed no more Pd.
Silver metal from cementing with zinc powder and hcl.

How did you actually do this?
What I have been seeing on the forum is either the NAOH-syrup or Iron-H2SO4 method.
Your way seem more simple and direct, also the Pd cementing directly from DMG salt, seem very direct comparing to what has been the usual outline on the forum.

 

[kjavanb123]

Hi Kjavan!
I just revisited this thread, and your silver cementing just puzzled me.

You said

Silver chloride was filtered and washed throughly with hot water till the solution passed the filtee turn clear and stannous test showed no more Pd.
Silver metal from cementing with zinc powder and hcl.

How did you actually do this?
What I have been seeing on the forum is either the NAOH-syrup or Iron-H2SO4 method.
Your way seem more simple and direct, also the Pd cementing directly from DMG salt, seem very direct comparing to what has been the usual outline on the forum.

Hi

Silver chloride can be converted to metallic silver using zinc powder as the following;

1- Wash and rinse the silver chloride till solution is clear.

2- Add water till all silver chloride powder is covered.

3- Sprinkle zinc powder and mix it well with solver chloride powder, check the bottom of beaker to be sure no more white silver chloride is seen.

4- Slowly add muratic acid to the mix, and stir.

5- Wait till bubbling stopped, then add more hcl to make sure zinc is removed completely.

6- Wash and rinse with hot water till pH of water rinsed is 7.

7- Dry the silver metal powder and melt.

Procedure for cemeting Palladium from DMG Pd yellow salt is very similar to above, except more stirrig and smaller addition of hcl is needed due to boil over.

These methods are straight and simple.

Hope that help
KJ

 

[Yggdrasil]

Thanks Kjavan.
Interesting that this method hasn't been covered more.
How are the losses comparing to the Lye Sugar or Iron Sulphuric method?

 

[FrugalRefiner]

Interesting that this method hasn't been covered more.

It is. A search for HCl zinc silver will turn up around 400 results. Of course, a lot aren't on point, but plenty are.

Dave