What should be done next? please help!

[gaurav_347]

I am in a bit of a fix. I am recycler based in Central India and i have a level 1 and level 2 plant where the machines are able to remove the epoxy from the printed circuit boards leaving behind only metals. I am planing to go to level 3 now which is refining . I have considered the option to export the pcbs or the metals to the refineries or smelters in Europe and Japan but it takes a lot of time for the whole process say about 4 months till you receive the payment. How should i go about refining these metals on my own. I am only interested in copper ,gold, silver and tin and other metals if feasible. the ferrous metals are already removed in the level 2 plant.

If you were in my position how would you go about refining these metals. We can process about 1 ton of pcbs which usually yield about 20% of metals. So about 200-220 kgs in a day. What sort of machinery would i need. We have all the necessary space, electricity and the manpower required. i am posting a picture for your reference of how the metals look. Thank you once again.

 

[necromancer]

this is hard to recognize, do you have a better photograph ?

 

[nickvc]

The most cost effective method would be to use cells. As the major constituent of pcb metals is copper maybe look to set up a copper refining operation, there are plenty of details freely available as how this is done. The one problem is that all electrolytic systems need high grade feed stock for them to run efficiently and without constant need of electrolyte changes as they foul, this means taking good samples from your materials and melting and then either assays or use a good, well set xrf to determine the copper content of your material. Ideally the material needs to be 95%+ copper so the assays or xrf readings will tell you how much copper you will need to add to reach the ideal percentage for the cells. The copper from the cell will eventually cover the need for good copper to add and then later you should have pure copper to sell on, the values Au, Ag, Pt and Pd will report in the slimes along with all the other metals.
The choice then is either refine the slimes yourself or melt,assay and sell, you will probably still have a high percentage of copper but the values will be a much higher percentage than with the material as a whole. The one problem element you will encounter is tin but there may be others which will hinder your processing from here and assuming any tin will have formed its wonderful paste form filtering may well be your first headache. The processes needed to refine the values are well documented on the forum but this mix may well present you with some challenges, not insurmountable with study and practice but I would be tempted to try a small scale cell before you go onto a larger operations to see if you can refine the slimes and what problems you are likely to encounter and the equipment and methods to succeed.

 

[gaurav_347]

this is hard to recognize, do you have a better photograph ?

 

[gaurav_347]

The most cost effective method would be to use cells. As the major constituent of pcb metals is copper maybe look to set up a copper refining operation, there are plenty of details freely available as how this is done. The one problem is that all electrolytic systems need high grade feed stock for them to run efficiently and without constant need of electrolyte changes as they foul, this means taking good samples from your materials and melting and then either assays or use a good, well set xrf to determine the copper content of your material. Ideally the material needs to be 95%+ copper so the assays or xrf readings will tell you how much copper you will need to add to reach the ideal percentage for the cells. The copper from the cell will eventually cover the need for good copper to add and then later you should have pure copper to sell on, the values Au, Ag, Pt and Pd will report in the slimes along with all the other metals.
The choice then is either refine the slimes yourself or melt,assay and sell, you will probably still have a high percentage of copper but the values will be a much higher percentage than with the material as a whole. The one problem element you will encounter is tin but there may be others which will hinder your processing from here and assuming any tin will have formed its wonderful paste form filtering may well be your first headache. The processes needed to refine the values are well documented on the forum but this mix may well present you with some challenges, not insurmountable with study and practice but I would be tempted to try a small scale cell before you go onto a larger operations to see if you can refine the slimes and what problems you are likely to encounter and the equipment and methods to succeed.

Thank you so much for your help . We took out some results from the labs based in Japan and India and the copper content usually ranges from 55-63 % of the metal mixture of 1 ton depending on the type of board you are crushing.

 

[gaurav_347]

Are there any systems which are readily available in the market for refining such kind of metal mixture for about 200-300 kg/day capacity?

 

[RikkiRicardo]

gaurav

Listen to Nickvc so far you are doing it right now you want to do the recovery of the metals so you will have set up a Electrowinning copper unit then go after the sludge Now i would also like to know what you did with all the magnetic parts? and the aluminum capacitors and aluminum Did you use a electrostatic separator? or just magnetic separator ? this is all very
important you might just be throwing away value are you using one of the China units.If you don't use the Electrowinning you will be just spending to much money in Acids for that kind of recovery From what i can see you will have to hire someone to come there and consult you on your operation for the Refinery or you will be wasting your money and time.
There is a lot to learn.There are a lot more metals to recover if done right.



RikkiRicardo

 

[RikkiRicardo]

gaurav


6 Months ago you where asking the same questions What i have see from your other topics from that assay that is very low
(mixed metal fractions) from one of your old topics.
Have you sent any of your stuff out??? And what price did you get per Ton? of this type of material.

RikkiRicardo

 

[4metals]

Gaurav,

The answer Nick gave you based on your question is excellent and if refining in house is the route you choose, follow his excellent advice. If you can make your feedstock 95% copper it is relatively easy to scale up to the size electrolytic facility you will need.

But that is not the end of the story. Now you will be tasked with routinely incinerating some nasty anode bags to prepare the slimes for chemical refining. For this you will need incineration capacity and an acid refining capacity to process your precious metal into sale-able form. (ie. 999+ metal)

If you go that route, you will still have to find a buyer for your precious metals and they are always purchased at a discount so you are likely to be selling under market price.

Another option is to consider what you have. From my perspective that is one beautiful photograph!

Lets discuss the main thing a business sending out scrap to a refiner has to deal with, and that is how much metal is really in my material. I get requests from scrap collectors all of the time and all are unsure of the content. There are different ways a refinery can come to determine how much metal is in the scrap. Some incinerate to burn off the non metallic materials and produce a powder which contains precious metals and a pile of charred metal which is not as pretty as your pile. They then melt and assay the charred pile and have low grade copper based bullion to ship to a copper refinery.

Considering what you would have to spend to process 200 - 220 Kg a day followed by what you will have to do to recover the PM's and get paid for them, I would choose another option.

Remember most people who call themselves low grade refiners are really sampling houses. The one thing they do is produce a homogeneous sample. That is the most important thing here, a homogeneous sample.

Your little pile in the picture which has had the ferrous metals separated out is just a melt away from being that homogeneous sample. If it were me, I would first get a good melt furnace, one with a capacity of 250 Kg of your material so you can do melts on a single days production. They can be sampled while molten and poured into 30 Kg bars and you will have a representative sample of your entire days production. Now you need to do a fire assay.

There are many reputable copper refiners who give out very good rates for this material. The key is knowing your assay before you ship.

The step I outlined above requires equipment and analytical skills that you will have to have even if you go the electrolytic copper refining route, so it is a natural first step. If you ever do get to running your own refinery, not having the ability to analyze your material and control your in house refining accountability is the first step to going out of business. So the analytics are a must anyway.

Once you are producing your own copper based bullion bars in house and have the ability to assay them to settle your customer, it is an easy calculation to compare what it costs you to ship it to a copper refiner vs. the set up and operating expense of refining yourself.

I would think you will stop at melting and assaying your own bars and shipping to a copper refiner.

Shipping out bars that you know the assay of eliminates the wiggle room that shipping unquantified scrap gives to your refiner.

 

[RikkiRicardo]

4metals

Well said this is the only way to go.
This is a way that I'm going with PCB electrolytic copper refining route then melting the sludge to bars then Fire assay.
There is stuff that we will refine in house.
Just for 250 kg electrolytic copper refining unit is a big cost and a big unit you would need just for the rectifier over 4000 amps and how many tanks.

RikkiRicardo

 

[nickvc]

I have to say of the two options the melting, assaying and selling of your material will be the one with the least headaches and least outlay financially. Assaying your own materials would also be advantageous unless you have access to fast and reasonably cheap assays which are accurate.
4metals knows this business inside out so heed whatever he suggests, refining isn't always the best choice and in many cases the worst if good rates are available on whatever you have.

 

[4metals]

Keep in mind that the big refineries are like other businesses, they want to turn around their metal as fast as possible. If they receive bars from you which they can process directly in their system after sampling, their turn around time should be less and your payout will come quicker. I always added copper to my copper based bullion bars because they were paying me for copper anyway and the bars they received were remelted and sampled and poured directly into anodes quickly because they were received 95%+ copper already. They had to do less and I was paid faster.

Even if you do it in house, your capacity to plate the pure copper only determines how fast you can sell the copper. So 220 kilograms of pure copper plated out per day determines your electrolytic recovery equipment needs. You then have to wait for the slimes, which are the concentrates containing the precious metals, to accumulate into quantities that are efficient to process. That can take a month before you even start on the precious metals in house.

 

[g_axelsson]

Gaurav, when I see your metal pile I only have one question, what are you doing with the plastics? I would suspect a lot of gold is contained in bond wires, locked in the epoxy plastics of the chips. When shredded I would suspect it would follow the plastic fraction.
Do you have a way of extracting the gold from the plastics? Have you tested the plastics for the gold content?

Maybe you only runs low grade scrap so this isn't an issue. I'm just curious.

I don't have any practical experience of running shredded circuit boards so I could just be wrong about where a large part of the gold ends up.

Göran

 

[goldsilverpro]

Note: I wrote this before the 3 previous posts were made.

I agree with 4metals. The simplest, cleanest, most profitable way would be to melt, sample, assay, cast ingots, and ship. It would take 4 months to "fill the pipeline" but, after that, you would be receiving regular checks. Also, you may be able to get partial advances during the 1st 4 months, but you would likely have to pay interest.

To me, it would be best to get a 250kg tilt induction furnace rather than a gas furnace. An induction furnace agitates the molten metal and makes it much more homogeneous than a gas furnace does. Therefore, pin samples (I would take at least 3 per melt and run at least triplicate assays) from an induction furnace would represent the entire melt. With a gas furnace, you would probably have to pattern drill each 30kg bar and assay the bars separately. Also, the induction furnace would melt most any combination of metals. With a gas furnace, you would likely have to add more copper, in order to lower the melting temperature enough so everything would melt.

As 4metals said, you MUST know what's in those bars before they are shipped. The best way to do this is to setup and learn accurate in-house sampling and assaying.

When magnetically separating, you would also remove the Kovar, which is often gold plated. Have you tested the magnetic fraction for gold? What percentage of the total is magnetic? If it's low and if you use an induction furnace, it may be better to leave it in. Also, I would bet there are PM values in the other materials (organics, ceramics, etc) that were separated from the metallics.

To run an electrolytic cell, you would have to cast anodes by melting the grain, along with a lot of extra copper. Assuming you had 100 pounds of material that ran 60% copper, you would have to add an extra 600 pounds of pure copper to get it to 95%. Also, there are probably 20 different metals represented in your metallic material. Some will end up in the anode slimes, but some will enter the solution and, in a fairly short time, it will be contaminated to the point where it will be "poisoned" and you will have to change it in order to continue getting decent cathode copper.

I can think of ways to dissolve the base metals, but this would require lots of chemicals, lots of labor, fume control, etc. I can think of none that would be profitable on this low grade material.

All in all, I think that processing this material yourself is a bad idea and much less profitable than simply melting and shipping. The lack of income for 4 months would be a cheap price to pay, compared with the high costs and potential problems of refining it yourself.

 

[4metals]

The potential for precious metal in the plastics fraction is high. Back in the day when I incinerated this type of material, the material was crushed and sifted to get to the metal fraction. I would assume that at least a percentage of the PM value in the powder resulted from the grinding process. It does make sense that some of it was also a result of the physical separation process you use. You have said nothing of how you do the physical separation.

A little input as to how you do that and the types of equipment may be useful here.

GSP is right about plated kovar in the magnetic fraction, I always kept that portion separate and it never was up to payable limits. As your material has not been burnt, any plating in the steel can be seen and physically picked out and put in the copper based fraction. In my experience, it wasn't worth processing the magnetics in house, all of the house magnetics were shipped to JM for us to witness a very large copper melt to get paid on the PM content. Keep in mind this was back in the day of $300 gold, I'm not as young as I used to be and things have changed!

If you get paid for the different types of plastic it may be more cost effective to sell it as plastic than to try to extract any PM's. A test incineration of a sample of the material, crushed and sifted in a cleaned mill and sifter (to avoid contamination of a sample) will tell the story. Cross contamination can really hurt you here so be sure you sample in cleaned equipment.

If you have a process where you can process a ton a day of circuit boards and end up with the material you have shown, you could build a decent business around the witness and sample your boards process. You could charge a straight per pound incoming fee and a refining charge and retain a percentage of the values. Not easy to get that done these days.

 

[4metals]

GSP said;

To me, it would be best to get a 250kg tilt induction furnace rather than a gas furnace. An induction furnace agitates the molten metal and makes it much more homogeneous than a gas furnace does. Therefore, pin samples (I would take at least 3 per melt and run at least triplicate assays) from an induction furnace would represent the entire melt. With a gas furnace, you would probably have to pattern drill each 30kg bar and assay the bars separately. Also, the induction furnace would melt most any combination of metals. With a gas furnace, you would likely have to add more copper, in order to lower the melting temperature enough so everything would melt.

I agree about the melter being induction. I was recently with a client witnessing a large low grade melt and they did not sample with pin dips. They actually sampled the way I did it 30 years ago with gas furnaces. They started the pour and put a clean small crucible in the metal stream and poured it onto a plank of wood lying at an angle in a metal pail full of water. They directed the stream of metal at the wood / water interface. This produced fine BB's as samples.

They did this at the beginning of the melt, in the middle, and at the end. The pour lasted about 5 minutes so they needed to be set up with 3 pails with planks as there was little time to waste.

Each sample was screened to produce a small pile of balls about 1/8" to 3/16" in diameter.

The samples were not mixed but given to us and the lab as beginning, middle, and end pour samples.

The proof of the mixing ability of the induction furnace was in the fact that all of the samples assayed very close to each other.

I thought some of the older refiners might relate to this technique.

 

[goldsilverpro]

You have said nothing of how you do the physical separation.

A little input as to how you do that and the types of equipment may be useful here.

I totally agree. It would be very helpful to know that.

 

[necromancer]

not sure if these are helpful to you, but here they are
some are old, prices are very out of date.

 

[gaurav_347]

gaurav

Listen to Nickvc so far you are doing it right now you want to do the recovery of the metals so you will have set up a Electrowinning copper unit then go after the sludge Now i would also like to know what you did with all the magnetic parts? and the aluminum capacitors and aluminum Did you use a electrostatic separator? or just magnetic separator ? this is all very
important you might just be throwing away value are you using one of the China units.If you don't use the Electrowinning you will be just spending to much money in Acids for that kind of recovery From what i can see you will have to hire someone to come there and consult you on your operation for the Refinery or you will be wasting your money and time.
There is a lot to learn.There are a lot more metals to recover if done right.



RikkiRicardo

We use magnetic separator to remove any kinds of ferrous metals . The machines are made in India itself but based on the chinese concept with some modifications made for reducing the metal loss. I agree with you Rikki there is much to learn and there is no one way to process the information as there is always an alternative information available which feels better to put into practice and this creates a lot of confusion. I am already consulting someone regarding the recovery. Thank you for the help.

 

[gaurav_347]

Gaurav,

The answer Nick gave you based on your question is excellent and if refining in house is the route you choose, follow his excellent advice. If you can make your feedstock 95% copper it is relatively easy to scale up to the size electrolytic facility you will need.

But that is not the end of the story. Now you will be tasked with routinely incinerating some nasty anode bags to prepare the slimes for chemical refining. For this you will need incineration capacity and an acid refining capacity to process your precious metal into sale-able form. (ie. 999+ metal)

If you go that route, you will still have to find a buyer for your precious metals and they are always purchased at a discount so you are likely to be selling under market price.

Another option is to consider what you have. From my perspective that is one beautiful photograph!

Lets discuss the main thing a business sending out scrap to a refiner has to deal with, and that is how much metal is really in my material. I get requests from scrap collectors all of the time and all are unsure of the content. There are different ways a refinery can come to determine how much metal is in the scrap. Some incinerate to burn off the non metallic materials and produce a powder which contains precious metals and a pile of charred metal which is not as pretty as your pile. They then melt and assay the charred pile and have low grade copper based bullion to ship to a copper refinery.

Considering what you would have to spend to process 200 - 220 Kg a day followed by what you will have to do to recover the PM's and get paid for them, I would choose another option.

Remember most people who call themselves low grade refiners are really sampling houses. The one thing they do is produce a homogeneous sample. That is the most important thing here, a homogeneous sample.

Your little pile in the picture which has had the ferrous metals separated out is just a melt away from being that homogeneous sample. If it were me, I would first get a good melt furnace, one with a capacity of 250 Kg of your material so you can do melts on a single days production. They can be sampled while molten and poured into 30 Kg bars and you will have a representative sample of your entire days production. Now you need to do a fire assay.

There are many reputable copper refiners who give out very good rates for this material. The key is knowing your assay before you ship.

The step I outlined above requires equipment and analytical skills that you will have to have even if you go the electrolytic copper refining route, so it is a natural first step. If you ever do get to running your own refinery, not having the ability to analyze your material and control your in house refining accountability is the first step to going out of business. So the analytics are a must anyway.

Once you are producing your own copper based bullion bars in house and have the ability to assay them to settle your customer, it is an easy calculation to compare what it costs you to ship it to a copper refiner vs. the set up and operating expense of refining yourself.

I would think you will stop at melting and assaying your own bars and shipping to a copper refiner.

Shipping out bars that you know the assay of eliminates the wiggle room that shipping unquantified scrap gives to your refiner.

Thank you for your support and the knowledge you provided . I had never considered this option before so now i surely will. Can you recommend me some refineries who would be interested in such bullion bars?