Please help estimating Au content for these

[4metals]

So the seller is a middle man too? So you will just add another layer of middleman or are you the refiner?

I didn't check your math on the plating value, I was using your number.

Considering your time constraints, the ENIG is a very thin layer of gold and will not resist being "burned" through by nitric acid. Add a drop of nitric acid cut 50% with water to the board to see if the gold (or the electroless nickel under the gold) reacts. If it does, immersion gold is only a very thin layer and the boards are of considerably less value.

 

[hestati86]

So the seller is a middle man too? So you will just add another layer of middleman or are you the refiner?

I didn't check your math on the plating value, I was using your number.

Considering your time constraints, the ENIG is a very thin layer of gold and will not resist being "burned" through by nitric acid. Add a drop of nitric acid cut 50% with water to the board to see if the gold (or the electroless nickel under the gold) reacts. If it does, immersion gold is only a very thin layer and the boards are of considerably less value.

This!

Thank you so much!

So if it doesn't react, is there any "minimum guaranteed" layer thickness? From what level it will not react?

For the middle man... We have a contract with Aurubis, my seller gets the waste as a part of a total waste management contract he has with many companies. So no, there are no extra re sellers in between

 

[4metals]

ENIG General Applications The minimum immersion gold thickness shall be 0.05 µm [2.0 µin] at -4 sigma (standard deviation) from the process mean as measured on a pad size of 1.5 mm x 1.5 mm [0.060 in x 0.060 in] or equivalent area; the typical range is 0.075 µm to 0.125 µm [2.96 µin to 4.93 µin].

 

[anachronism]

This is how we often have to trade too. Offering a fast price so being safe is the name of the game. That product hasn't in my experience even got multiple layers of copper within it but that's not to say it's all the same.

Incidentally using a pencil eraser on the gold is also a good way to determine ultra thin flash plating. I've got some of that product so when I get back I'll use an eraser on it and show the difference.

 

[hestati86]

Eraser will take off ENIG?

 

[anachronism]

It can cut through thin flash plating. Try on a normal piece of ewaste plate like a finger, then on this material and see if there is a difference.

 

[4metals]

An eraser is a much user friendly test for sure, Jon, would you have any pictures to give an example?

 

[goldsilverpro]

I have done the pink pencil eraser thing probably a 1000 times. It's probably been 25 years since I've done it but, at the time, I was pretty good at distinguishing between thick, thin, or in-between plating and also whether it was solid or plated. I wound imagine that it would take very few strokes (say, 2) to remove 3-5 u" of immersion gold (IG), which by nature would have to be quite soft. Use moderate pressure and don't use a coarse ink eraser. The soft pink erasers on a good quality pencil, like a Ticonderoga, is what I always used. For fingers, I'm thinking it took 10-15 strokes. It's very subjective unless you've done it a jillion times.

A story. In L.A. in the 80's, there were lots of guys in parking lots selling gold chains and other jewelry that they claimed to have come from looting during the Newark riots. We were approached by a guy with a heavy chain. The markings said 14K and the price was about 1/3 of spot for solid 14K. I happened to have a pencil with me and asked the guy if I could use the eraser on the gold. I told him that, if the gold was solid, it wouldn't damage the chain. He said OK. After 2 strokes, a 1/2" streak of white nickel was exposed. Super thin color gold plated.

All of these estimate things are interesting but, if I were thinking about buying a ton of this stuff, I would want a true, well-sampled, group of fire assay analyses. I assume these "sets" are all the same. If so, sampling would be simpler. My gut feeling is, however, that this is very lo-grade crap and the gold thickness is nowhere near 20 u".

 

[hestati86]

Thank you for eraser test suggestions.

I am out to buy an eraser, but this "low grade crap" cannot be scratched off easily. I tried with a key and it take s a lot of effort to scratch through gold.

Getting my nitric and eraser. So nitric should be 50% concentration and just make a drop?

 

[kernels]

I'm a believer in the 50% (of 70%) Nitric too, but I find it helps to look at the reaction through a microscope. With ENIG you can see the little bubbles form 'through' the gold very quickly. On hard gold plating there is no reaction.

 

[kurtak]

I honestly have no idea how they do it. I know for sure that we can offer better price than Chinese, but at the same time since I dont know the content, I dont know how much to offer. Somehow Chinese seem to know...

Per the underlined - just wondering what makes you so "sure" that you can offer a better price then the China buyers ?

I ask because there are a couple things to consider here (with China buyers)

One is that China is a HUGE source of counterfeit products - so it is entirely possible that a China buyer could/would buy production failure (gold plating does not meet spec) boards for counterfeit product production - in which case they would not be concerned about gold recovery & therefor able to offer "a bit" more then gold recovery price - or in other words "buy blind" when it comes to gold recovery - because gold recovery is not the end intent - but rather re-use in (counterfeit) product production

Also - is the China buyer "the smelter/refiner" --- if so - then (1) they can offer more then a middle man buyer as the middle man is cut out - and (2) as the smelter/refiner (&/or even a LARGE volume middle buyer) - they have run enough LARGE LOT material through their operation (they have seen it ALL) that they already have a recovery data record & all they have to do is look at their data speed sheet on any given product (as mentioned by Jon & 4metals) to make there buy price offer --- its hard to compete with such buyers - unless you also have handled LARGE volumes of material & have a good data reference for buy pricing

Bottom line - you are playing in a VERY competitive market - especially if you are working in a market of sellers - selling to multiple "bidding" buyers (even is its a one day/one bid opportunity) --- in which case the best you can do is know your material - make your best offer on any given lot - & know you are going to win some & loose some - &/or even let some go if/when its material you don't know

Kurt

 

[4metals]

So nitric should be 50% concentration and just make a drop?

Nitric usually comes 68 to 70% (at least here in the states) and by 50% I mean half of the volume is distilled water and half of the volume is nitric acid, so it is not truly 50% but it is not critical either. But do not use the concentrated acid as the water helps get the reaction going.

 

[hestati86]

I honestly have no idea how they do it. I know for sure that we can offer better price than Chinese, but at the same time since I dont know the content, I dont know how much to offer. Somehow Chinese seem to know...

Per the underlined - just wondering what makes you so "sure" that you can offer a better price then the China buyers ?

I ask because there are a couple things to consider here (with China buyers)

One is that China is a HUGE source of counterfeit products - so it is entirely possible that a China buyer could/would buy production failure (gold plating does not meet spec) boards for counterfeit product production - in which case they would not be concerned about gold recovery & therefor able to offer "a bit" more then gold recovery price - or in other words "buy blind" when it comes to gold recovery - because gold recovery is not the end intent - but rather re-use in (counterfeit) product production

Also - is the China buyer "the smelter/refiner" --- if so - then (1) they can offer more then a middle man buyer as the middle man is cut out - and (2) as the smelter/refiner (&/or even a LARGE volume middle buyer) - they have run enough LARGE LOT material through their operation (they have seen it ALL) that they already have a recovery data record & all they have to do is look at their data speed sheet on any given product (as mentioned by Jon & 4metals) to make there buy price offer --- its hard to compete with such buyers - unless you also have handled LARGE volumes of material & have a good data reference for buy pricing

Bottom line - you are playing in a VERY competitive market - especially if you are working in a market of sellers - selling to multiple "bidding" buyers (even is its a one day/one bid opportunity) --- in which case the best you can do is know your material - make your best offer on any given lot - & know you are going to win some & loose some - &/or even let some go if/when its material you don't know

Kurt

Counterfeit is out of question.

China now cannot offer good prices UNLESS they go for reusing of chips. Actually, China is ACTIVELY moving their refineries outside of the country. They have an issue with bringing e-waste to the country, it's simply not allowed. Now, of course it's still possible, mainly through HK, but it makes things a lot more expensive (pay the customs, pay the middle man in HK, pay for storage and so on). Their process is far from perfect, they lose way too much. The ONLY reason they still can compete is the chip recovery, but we are also working on it now, to get the chips off, sell to China and send material to Europe.

To finish it up, our labor cost is cheaper than China, so we can sort here and then send to Europe. Bottom line, head to head they have no chance.

Actually, here we win any bidding war for populated boards, unless we hit the "chip recovery" territory. In that case, the price will shoot up like crazy and goes way over metal value. The unpopulated board is different though, I'm yet to meet ANYONE who has ANY rough idea how much value is in it.

It is funny actually how I met one buyer from China today, we discussed this board and he said he would not offer more than $1.5, which is half of what we offered and even with that price we didn't get it.

Hey it's Asia after all. There was a guy selling good boards but at almost 20 USD per kg, while the actual price is maybe 10. 3 months later, he still has these boards in his warehouse, even Chinese didn't buy it for chip recovery. He is just waiting for the next sucker in line and you see MANY cases like that here.

 

[4metals]

And you're a middleman and willing to jump into that mess?

Do you, or does someone from your company, witness the sampling at Arubis? If you could set yourself up to work as an agent of the generator of these scrap parts, and sell yourself as a service to witness and assure the sampling of the material at Arubis is fair and transparent and you get paid a percentage of the value. That way you have little risk and the generator will maximize their payout for the scrap because they will be paid on assay (since Arubis pays on sampling and assay)
so their payment would be the actual value, less refining charges (which are reasonable), less your percentage for your service.

Are you hiring?

By the way,

To finish it up, our labor cost is cheaper than China, so we can sort here and then send to Europe.

Where are you located?

 

[g_axelsson]

I almost got a feeling that someone have read this thread...

A video about different plating in nitric acid, viewed through a microscope.
[youtube]http://www.youtube.com/watch?v=iav_KH0PEZY[/youtube]

Successful Engineer, if you read this thread, thanks for the video.

Göran

 

[hestati86]

And you're a middleman and willing to jump into that mess?

Do you, or does someone from your company, witness the sampling at Arubis? If you could set yourself up to work as an agent of the generator of these scrap parts, and sell yourself as a service to witness and assure the sampling of the material at Arubis is fair and transparent and you get paid a percentage of the value. That way you have little risk and the generator will maximize their payout for the scrap because they will be paid on assay (since Arubis pays on sampling and assay)
so their payment would be the actual value, less refining charges (which are reasonable), less your percentage for your service.

Are you hiring?

By the way,

To finish it up, our labor cost is cheaper than China, so we can sort here and then send to Europe.

Where are you located?

A bit off topic here. I lived in US and Canada and had the same thinking and mentality when I first got here, to SEA. No offense, it's good, just not applicable here.

Chinese and Asians in general (except Japanese and MAYBE Koreans) do not think long term. $10 today is more important than potential $10,000,000 tomorrow. How are those total waste tenders are obtained? Money under the table. How do we export when it's not allowed? Money under the table. The person in charge wants to get $10 from you TODAY, because maybe tomorrow he's fired, he will never get his share from you.

I mean it sounds like a total mess, but it's not when you know people. I was even invited to few "meetings" that went something like that (very politely)

- sir, do you know that we have Mr. Loh from Department of Industry as a partner. We would ask you not to participate in this and spoil our market
- Yes, but my partner is a good friend of Mr. Mahdi, city council deputy and vice-mayor so please kindly f-off
- oh, sorry sir, please kindly continue your business


Back on topic, thanks for the video on nitric acid!!!