Regards contacts

Hi
Here is what happen i started with old central telephone contacts
dissolved in nitric acid in till no reaction at the bottom of the vessel was grey powder solution green tested for pd test color green.So my thought that i have dissolved both silver and Pd
Now the gray powder i grabbed a spoon full and made AR results from test was orange so my thought is pt .Washed the gray powder 5 times then dried it.
then i tried to melt this and there was a lot of smoke This is a picture of the results what i got what can the green stuff that looks like a resin be it crumbles very easy. there is silver color beads mixed in this.
it was only metal when i started with nitric this stuff is from the nitric not the AR.


RikkiRicardo

Were the points still on the bus bars when you put them in nitric ? (bus bar nipped close to point but some bus bar still remaining) if so there's a good chance its beryllium - beryllium/copper is a common alloy used for telecom bus bars - beryllium dissolves in in HCL & sulfuric but not in nitric so when its alloyed with copper & then dissolved in nitric the beryllium remains un-dissolved much the same as stannic tin when dissolving bronze in nitric

Kurt

Kurtak

i took a spoon full sample and dissolved it in AR color of solution yellow orange test with stannous chloride test was orange



RikkiRicardo

RikkiRicardo said:

Kurtak

i took a spoon full sample and dissolved it in AR color of solution yellow orange test with stannous chloride test was orange



RikkiRicardo

Click to expand...

Yes I understand that - Pt & Pd are common with telecom points so a Pt positive stannous test is not unlikely - however that does not mean all of the powders after the nitric treatment were PT - if there was any bus bar in the original nitric treatment there is a very good chance you ended up with beryllium as part of the un-dissolved powders that settled out when the nitric treatment was completed - so the un-dissolved powders would be beryllium along with some undissolved PT

The fact that it smoked a lot & the color of your slag tells me you had beryllium involved --- are the ball of melted metal light weight (like aluminum) ???

Kurt

Kurtak

No they are heavy If this was Beryllium would it not melt ? I have just been reading that nitric will attack powdered Beryllium is this true ? As for the slag what would that be from? Green and it crumbles so is this heavy in weight 40 grams is the weight that you see the stuff the just a bit bigger of the size of a quarter two quarters high.


RikkiRicardo

I see some bee bee's in that, I count 4 of them right in the middle next to the big piece. Looks like it to me from the pic any how.

Smack
yes some metal did melt but what I'm trying to find out what can be the green stuff because all there should be is metal. When did dissolve the powder in AR it comes out yellow orange test shows PT and everything dissolves.

RikkiRicardo

Nitric acid, probably some brass, grey powder in the bottom. I would suspect tin at first. I don't see any technical reasons for beryllium.

As the grey powder dissolved in AR but when melted it turned into that green gray glass and smoked a lot it could have been some silver chloride. Are you sure you have chlorine free water and nitric? Maybe some chloride contamination from the jewellery. Did you incinerate the jewellery first?

Göran

Goran

all the gray powder was the left over from the nitric then i filtered then heated dry the washed with tap water still at this time was thinking that all the powder would be
PT because i did a spoon full of the powder in AR an all dissolved then tested for pgm and there was no silver chloride could this be pd chloride or Nickel(II) chloride ?

RikkiRicardo

I don't know what it could be, but your melted mass looks like a melted salt, not as platinum powder.

If it dissolves in AR then you could dissolve -> denox -> cement on copper. That should leave you with a gold / pgm powder, the rest of the solution could be discarded (after testing and confirmed barren) and your black powder concentrate should contain the precious metals that you started with. That could be further refined when you got enough material to process.

Göran

g_axelsson said:

I don't see any technical reasons for beryllium.

Did you incinerate the jewellery first?

Göran

Click to expand...

Goran

His starting material was not jewelry it was telecom contactor points - I have processed a lot of these type points - they can be (the points them selves) pure Ag pure Pd pure Pt or alloys of those metals as well as alloys of other metals like nickel

The technical reason for the beryllium is in the bus bar that the points are mounted (brazed) on - these points are opened & closed by way of a magnetic coil - because of the many thousands of times they are expected to open & close over there expected time of operation the bus bars are almost always (if not always) a beryllium alloy of some sort (most common is beryllium/copper but I have also seen beryllium/brass & beryllium/nickel/copper)

In fact you can expect the bus bars out of most any magnetic controlled relay to be a beryllium alloy of some sort ( the most common being beryllium/copper)

The beryllium (2%) gives the copper a spring like property there by preventing stress cracking & braking - that along with the fact that beryllium its self has good conductivity properties is why beryllium alloys are used in this application

which is why I keep asking if any bus bar was put in with the original dissolving of the points --- another words did he clip the bus bar close to the point & then throw the points still on a small portion of the bus bar in the nitric to be dissolved

If so - then the stuff that does not melt & does all the smoking is most likely beryllium - & if he breathed any of those fumes (smoke) he likely got a good does of beryllium poisoning which is not a good thing

Kurt

Green color can be a few different things. since yellow and blue make green, that widens the possibilities to cover things that leave all three colors. Cobalt,nickel,iron,copper just to name the most likely culprits.

Are there photos of what they looked like before you treated them? Both the complete assembly and a close-up of the individual points would be nice.

kurtak said:

g_axelsson said:

I don't see any technical reasons for beryllium.

Did you incinerate the jewellery first?

Göran

Click to expand...

Goran

His starting material was not jewelry it was telecom contactor points - I have processed a lot of these type points - they can be (the points them selves) pure Ag pure Pd pure Pt or alloys of those metals as well as alloys of other metals like nickel

The technical reason for the beryllium is in the bus bar that the points are mounted (brazed) on - these points are opened & closed by way of a magnetic coil - because of the many thousands of times they are expected to open & close over there expected time of operation the bus bars are almost always (if not always) a beryllium alloy of some sort (most common is beryllium/copper but I have also seen beryllium/brass & beryllium/nickel/copper)

In fact you can expect the bus bars out of most any magnetic controlled relay to be a beryllium alloy of some sort ( the most common being beryllium/copper)

The beryllium (2%) gives the copper a spring like property there by preventing stress cracking & braking - that along with the fact that beryllium its self has good conductivity properties is why beryllium alloys are used in this application

which is why I keep asking if any bus bar was put in with the original dissolving of the points --- another words did he clip the bus bar close to the point & then throw the points still on a small portion of the bus bar in the nitric to be dissolved

If so - then the stuff that does not melt & does all the smoking is most likely beryllium - & if he breathed any of those fumes (smoke) he likely got a good does of beryllium poisoning which is not a good thing

Kurt

Click to expand...

I just filed that one away in the noggin cabinet. Thank You for that post.

First let me put a point my whole lab is all about safety 7 fume hoods cabinets full size scrubber all my filtering is done air vented cabinets also my melting is controlled with air vents My health is important i love life.

Now back to the topic yes the stems were added But first i did a test on just the stems and there was no gray powder left behind.
that i tried to melt and this is what the piece looked like after trying to melt it why is even the green yellow stuff is heavy the little metal BB's are also heavy.

goldsilverpro

i will get you some pictures

RikkiRicardo

The weight of the metal does not change when you change the state of the metal (one pound solid metal = one pound of melted metal). If you dissolve a pound of metal into X amount of fluid, the fluid now weighs X amount plus the one pound of metal. The flux is a liquid at high temps and the metal that is absorbed increases the overall weight by the weight of the metal. Grind a sample very fine and refine it. If it contains gold or other precious metals, it will be easy enough to test after you have it dissolved. Use a large enough sample to see a difference if there is one. Short of having an assay performed, the only one that can determine whats in it is you.

Kurt, I stand corrected, I have always thought that the blades in relays were made from brass or bronze but after making some research it seems it is quite common to have beryllium copper alloys in relays.

It only shows that to assume something is the fastest way to make an donkey of yourself. :mrgreen:

I agree with you, melting copper beryllium alloy is dangerous and I can only assume (here I go again) that trying to melt something with beryllium in is equally dangerous.

About melting beryllium copper...

Beryllium Coppers. These alloys are very toxic and dangerous if beryllium fumes are not captured and exhausted by proper ventilating equipment. They should be melted quickly under a slightly oxidizing atmosphere to minimize beryllium losses.

Click to expand...

Interesting, beryllium is turned into beryllium oxide by nitric acid. As dispersed as it is in an alloy it ought to be an almost complete transformation, leaving no beryllium metal left. The oxide is really stable under high temperature as BeO is a refractory material .
Source: wikipedia

Since the beryllium oxide is stable under heat the main danger of beryllium oxide is dust, not evaporation. That means the slag from the melt is composed of something else than beryllium. But still, there could be beryllium oxide mixed in the slag.

This is a purely theoretical theory of mine based on research online, I have no experience of melting beryllium or beryllium oxide.

What I said about jewellery was my mistake, I had just read about the unknown precipitate when denoxing in another thread and mixed it in here. Sorry about that.

Göran

Good glad to hear you have a safe working set up

Now that we know that some of the bus bar went into the nitric treatment we can determine that this is (in part) where the stuff that smokes a lot & does not melt is coming from --- the bus bars from these type contactors can be made of many different alloys (most of which will contain about 2% beryllium for the reason mentioned in my last post)

The other place it could be coming from would be from the braze/solder used to attach the point to the bus bar

I have processed hundreds of pounds of contact points over the last 4 years - it is about 95% of the source that I get my silver (& some PGMs) from - I am currently working on a batch that should net me about 10 lbs silver along with some more PGMs (Pd for sure) when I run it in the silver cell & I have something like 8 or 9 barrels 55 gallon drums) full of contactors of all kinds (magnetic disconnects, relays, circuit braker's & switches)

The point is that the alloys used in making the bus bars &/or braze is almost endless including bus bars made of invar &/or kovar

so from these alloys (both braze & bus bar) you are almost always (if not always) going to get a base metal precipitate that goes undissolved in the nitric treatment

That base metal precipitate may well contain PGMs that went un-dissolved in the nitric treatment

You have 3 choice's - you can dry the residue - incinerate to turn the un-dissolved base metals to oxides & then treat with hot HCL & then take the remaining solids to AR (you will get some Ag/CL to carry along) also check you HCL wash for Pd as if there was any finely divided Pd it will dissolve in the HCL

Or smelt (which is what you did here) this will remove "some" of the trash & give you metal to work with

Or just go to AR & send it to the stock pot for cementing later

The bottom line here is you are working with very contaminated stuff that contains base metal trash so you are going to get drag down &/or carry through of those base metals so you will most like need to work it & rework it at least a couple (if not several times) to get to your pure metal

Also you will most likely suffer "some" PM loss due to colloids

Kurt