Entire RAM sticks in Cu(II)Cl

[GoIdman]

Just what chips are you talking about that have gold plating ???

I ask because the ONLY chips I have seen with gold plating on them are ceramic chips --- or a VERY SMALL amount of plating on the fiber part (not the black epoxy part) of BGA chips

I have never seen gold plating on run of the mill black epoxy chips & used to process 500 - 600 pounds of black epoxy chips a year & have never seen them with gold plating --- they are processed for the gold bonding wires inside of them

I would like to see pictures of the chips you are talking about - that have gold plating on them

Kurt

I have depopulated some RAM sticks this weekend and indeed there are some BGA type RAM chips, that have gold plated pads under it (pads which are not functional use therefor are not soldered), i will post some pictures for you...i cant say if they were older or never RAM sticks. (my mistake, should have documented that for yield purposes)

Be safe

Pete

 

[kurtak]

I have depopulated some RAM sticks this weekend and indeed there are some BGA type RAM chips, that have gold plated pads under it (pads which are not functional use therefor are not soldered), i will post some pictures for you...i cant say if they were older or never RAM sticks. (my mistake, should have documented that for yield purposes)

Be safe

Pete

Correct - BGA chips will always have a VERY SMALL amount of gold plating - on the solder pads

or as I said

or a VERY SMALL amount of plating on the fiber part (not the black epoxy part) of BGA chips

which is why I asked BShan just what chips he was talking about

It is also the reason why BGA chips should be run separate from other - run of the mill (non BGA) black epoxy chips

(pads which are not functional use therefor are not soldered)

Its not just the pads without solder that are gold plated - but ALL the pads - when originally made - had - gold plating on them --- however - when they solder the chip - the solder dissolves the gold plating & the gold (plating) ends up being alloyed with the solder

Therefore - if you take a BGA chip - that still has the solder balls on the bottom of the chip - put it in HCl to dissolve the solder away - it will look like there is no gold plating under those solder balls

That is because the gold plating - that was - on those pads - when they originally made the chip - ends up being dissolved - by the solder - during the soldering process - & ends up in the solder - instead of remaining on the pads as gold plating

That is why if you put say 10 pounds of BGA in a bucket with HCl to dissolve the solder balls away from the (BGA) chips you will end up with a bunch of black powder in the bottom of the bucket

That black powder will be a combination of antimony & gold & that is because during the soldering process the solder dissolved the gold plating - resulting in the gold being alloyed with the solder (tin)

So you can recover that gold from the black powder - but first you have to wash the HCl that was used to dissolve the solder (tin) out of the black powder

In other words you can recover the gold in that black powder - but it is a process in & of its self

Kurt

 

[trdking]

Very interesting thread. I for one am very curious about your final yield and values from 9 pounds of ram THis is so tough to get an approximate yield from because Ram is so variegated. Some have many more chips than others some are single sided with chips and some double sided. My question has been for a very long time Does it make sense to sell ram to processors for $22 a pound today price or process and enjoy additional profit. I currently do not have a lab set up because of my current living situation but I am getting a about a pound of ram a week .On average a pound is about 21 sticks.

 

[GoIdman]

Correct - BGA chips will always have a VERY SMALL amount of gold plating - on the solder pads

or as I said


which is why I asked BShan just what chips he was talking about

It is also the reason why BGA chips should be run separate from other - run of the mill (non BGA) black epoxy chips


Its not just the pads without solder that are gold plated - but ALL the pads - when originally made - had - gold plating on them --- however - when they solder the chip - the solder dissolves the gold plating & the gold (plating) ends up being alloyed with the solder

Therefore - if you take a BGA chip - that still has the solder balls on the bottom of the chip - put it in HCl to dissolve the solder away - it will look like there is no gold plating under those solder balls

That is because the gold plating - that was - on those pads - when they originally made the chip - ends up being dissolved - by the solder - during the soldering process - & ends up in the solder - instead of remaining on the pads as gold plating

That is why if you put say 10 pounds of BGA in a bucket with HCl to dissolve the solder balls away from the (BGA) chips you will end up with a bunch of black powder in the bottom of the bucket

That black powder will be a combination of antimony & gold & that is because during the soldering process the solder dissolved the gold plating - resulting in the gold being alloyed with the solder (tin)

So you can recover that gold from the black powder - but first you have to wash the HCl that was used to dissolve the solder (tin) out of the black powder

In other words you can recover the gold in that black powder - but it is a process in & of its self

Kurt

Indeed, as you described, just wanted to add some photos for those who are interested...

Be safe

Pete

 

[dpgold]

Thank you for the quick reply. My thought is hmmmmm head scratcher... I "thought" everything I've read and seen is that you should use a cotton filter to filter the AR after adding sulfamic (while still hot, then let cool to draw down any lead). So after that cotton filter process, I rinse the cotton filter through with water. I thought in order to drop gold from AR with SMB you want to double the volume of liquid by adding 100% more water. So my process is to rinse my cotton through with water to about 25% increased water volume, then add 25 - 50% more water+dissolved SMB to the filtered AR solution. This gets me a fairly consistent gold drop.

But something is apparently going on since I have this purple color forming. Either I didn't rinse well enough, or it's something else. I always keep all my filters. I intend to process all filters and "gunk" that the filters catch one day because I know, no matter what, I always wind up leaving some values in the filters. Right now, I only have one and a half large Vlassic pickle jars worth.

So cotton filtering AR is not the way to go? I should use coffee filters? Is that providing enough filtration to filter out any cloudy particulates, I wouldn't think so.

from my research coffee filters have about 20 microns but there could be some which have smaller filtration, I looked up some of the filters have 2-5 microns but this would be a very slow filtering, the filtrate is rinsed and only the dissolved gold should go through in the case of AR but again I guess it depends on what material you put in AR.

 

[Shark]

Search the forum for “charmin filter”. This will work until you get better equipment.

 

[rickbb]

I use coffee filters, have for years, no problems. You can speed up the filtering process quite a bit with a vacuum filtering system. Any dissolved metal, gold included, will pass right through.

 

[Geo]

I use cotton balls for Charmin plugs. There is a slight danger of nitrating the cotton under certain circumstances. If you use cotton balls to filter with, store the used cotton in an airtight container while damp and do not let it dry. Be aware that gun cotton can still explode while damp. The probability of creating it in the first place is slim, but still possible.

 

[dpgold]

Thank you for the quick reply. My thought is hmmmmm head scratcher... I "thought" everything I've read and seen is that you should use a cotton filter to filter the AR after adding sulfamic (while still hot, then let cool to draw down any lead). So after that cotton filter process, I rinse the cotton filter through with water. I thought in order to drop gold from AR with SMB you want to double the volume of liquid by adding 100% more water. So my process is to rinse my cotton through with water to about 25% increased water volume, then add 25 - 50% more water+dissolved SMB to the filtered AR solution. This gets me a fairly consistent gold drop.

But something is apparently going on since I have this purple color forming. Either I didn't rinse well enough, or it's something else. I always keep all my filters. I intend to process all filters and "gunk" that the filters catch one day because I know, no matter what, I always wind up leaving some values in the filters. Right now, I only have one and a half large Vlassic pickle jars worth.

So cotton filtering AR is not the way to go? I should use coffee filters? Is that providing enough filtration to filter out any cloudy particulates, I wouldn't think so.

I had the same purple stains in the AP filter happening, did you find out what it was?

 

[Ohiogoldfever]

I can not remember any recommendations on cotton filtering.
Charmin plug for hard to filter solutions, yes, but for that fibreglass is recommended.

As in fiberglass batt? Insolation?

 

[Shark]

I use insulation. I prefer it when filtering solutions that the filter will be ran directly back in AR without heat. Then I can filter the fiberglass out on the next filtering process. The amount of heat I typically use won’t cause problems with the fiberglass but I prefer to not push my luck with it.

 

[Martijn]

I had the same purple stains in the AP filter happening, did you find out what it was?

Do you mean AP or AR?
Was there silver chloride in the filter and did it get exposed to sunlight?

 

[dpgold]

Do you mean AP or AR?
Was there silver chloride in the filter and did it get exposed to sunlight?

After I filtered AR from the weird mylars I kept the filters and hold them to dry in an open container in the sun and then discovered the purle stain, I could see that stain on the AP filters as well also dried in the sunlight. I did not see silver chloride it was not visible.