# RAM chips



## Romix (Aug 19, 2014)

This little square chips on RAM boards got good bit of gold in it and tin.






I Cracked so many of this rectangle chips, none of them had visible gold inside. 
There's solid shiny silver coloured metal, very magnetic. 
What is it? Maybe pure nickel? 




Same metal in this chips. 





Any one know what their fingers plated with?


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## solar_plasma (Aug 19, 2014)

a) http://en.wikipedia.org/wiki/Kovar
b) tin, no PMs


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## patnor1011 (Aug 19, 2014)

They all most then likely do have gold. You will not see it without magnifying glass and looking on correct spots. 
Easy check is if you thoroughly incinerate one and then wash ash away with water in some black or dark container. Use magnifying glass and you will see it.
Check thread in my signature.


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## Geo (Aug 19, 2014)

My experience with all these types of chips is to assume that they all contain gold and process accordingly.


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## Claudie (Aug 19, 2014)

The bonding wires are Gold like Patnor stated, but you won't see them without magnification. Most people use incineration to process them.


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## richard2013 (Aug 20, 2014)

Could it be the gold wires on picture B is cover by lead due to soldering? I also did crack those and no gold wire can be seen even using a magnifying glass.


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## Geo (Aug 20, 2014)

The wires are encased in the the black plastic. You can not see them unless you know exactly where and how to look. You will just have to take our word for it or you could give them all to me and I will pay the postage. 8)


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## richard2013 (Aug 20, 2014)

Wire bond should be connecting leadframe and silicon die,,in reballed RAM IC and BGA its very easy to see in magnifying glass the encased gold wires in the black mold compound but the picture B and C its none. Maybe we need a microscope lol. :mrgreen:


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## solar_plasma (Aug 20, 2014)

You got a lot valid infos, now. If you don't understand them, it's an indication for, you have to read, read and read the forum first. Without any background knowledge to question the valid answers of people, who are more than familiar with this kind of stuff, could be felt like a kind of disrespect and ignorance and that can be frustrating. The first I come to think in such situations is, why did you ask? If you don't find those gold bond wires, the mistake is with a chance of 99% yours, in some ICs (cheap bios kindred) it could be aluminium bond wires. Start with reading about gold bonding and about IC packages, for example on wikipedia, but also on the forum you will find a lot covering this.

This is not meant harsh or mean, but I try to show you the right direction.


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## richard2013 (Aug 20, 2014)

No problem with that solar,,the question was simply because viewing the bond wires like I did was not possible particularly on the RAM chips described. But it is not intended to disrespect anyone. It's what I saw using a magnifiying glass. Yes it could be possibly aluminum but before asking a question I already did my home work reading bond wire types which is gold, aluminum and copper but in this ram chips its not viewable. Any way I will proceed next to burn sample of ram chips as suggested.Thanks to you.


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## solar_plasma (Aug 20, 2014)

The gold wires are hard to detect without incineration. They are only around and close to the die.


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## kurtak (Aug 20, 2014)

solar_plasma said:


> The gold wires are hard to detect without incineration. They are only around and close to the die.



correct - to the best of my knowledge "ALL" RAM chips have gold bonding wire - they are a very, VERY small wire that make's the connection (bond) between the larger wire that comes off the circuit board & into the epoxy casing & the silicon chip (die) - which is why incineration is the only real way to liberate them for processing

Kurt


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## Romix (Aug 20, 2014)

I found that brown bottomed chips have much more gold in them then green chips.


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## solar_plasma (Aug 20, 2014)

What do you mean by brown and green bottomed chips? I only know black memory chips.


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## Claudie (Aug 20, 2014)

He may be referring to the North South bridges, verses the brown processor type packages. Just a guess though. :|


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## Romix (Aug 20, 2014)

Geo said:


> My experience with all these types of chips is to assume that they all contain gold and process accordingly.


You are right !!! 
I find it. 
Gold is above silicon in plastic.


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## Romix (Aug 20, 2014)

solar_plasma said:


> What do you mean by brown and green bottomed chips? I only know black memory chips.


Little square chips underneath where the solder. 
Brown or green.


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## Barren Realms 007 (Aug 20, 2014)

He might be talking about the fiber CPU's.


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## shmandi (Aug 20, 2014)

solar_plasma said:


> What do you mean by brown and green bottomed chips? I only know black memory chips.



Probably refering to BGAs. If you look at photo, some have greenish and some brownish bottom


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## Anonymous (Aug 20, 2014)

This thread's not about BGAs is it?


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## Anonymous (Aug 20, 2014)

Ok, some of the RAM chips on the first picture are BGA chips. There does seem to a be a little bit of confusion on the thread so far concerning these, as a lot of people do assume that a BGA is something like a northbridge chip. You can have BGA chips that are on RAM dimms, they are just a different construct to those that are the "high yield" BGA. 

For a RAM chips they are similar chips to the others on RAM just connected in a different way.

Dave (Frugal) thanks for pointing out to me the lack of detail in my previous post - I didn't explain my comment nearly clear enough.


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## g_axelsson (Aug 20, 2014)

Romix said:


> I found that brown bottomed chips have much more gold in them then green chips.


Are you talking about the BGA memory chips? (BGA = Ball Grid Array)

Do you have run some tests on yields? How does you know that there is more gold in the chips with brown bottom rather han the green? If you only goes by visual clues I would say that you are making a big mistake, most of the gold is in the bond wires and you need to know what to look for if you only have a hand lens, if you have a microscope the wires are easily spotted.
The gold that you can see with your eyes are only thinly plated and only a minor part of the gold in an IC.

If you have any yield numbers, please share it with us. I'm specially interested in the BGA memory chips. What I have seen in my microscope is that the chip is mounted upside down and the connections are along the center line of the chip. The solder balls are mounted on two small fiber boards on each side of the contact line and then bonded. The bond wires are covered in epoxy.

Göran


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## solar_plasma (Aug 21, 2014)

spaceships said:


> .............. You can have BGA chips that are on RAM dimms, they are just a different construct to those that are the "high yield" BGA. For a RAM chips they are similar chips to the others on RAM just connected in a different way............




I think they have less epoxy/silica material and no kovar legs, but the same technical values, which makes me expect more g/kg yield.

Those bga's in this link beneath are not the same, since they have only 64 contact points, but the construction might be pretty the same:

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=34&t=10973

So, as far as nobody proves the opposite, I count them as high yield (>1g/kg). If you have driven cars with 200 horses and you see another with 200 horses, you would expect it to be as fast as the others, if it seems to have the same shape as the others. Of course you could be wrong, maybe it does not drive at all, because it's made of cheap parts.


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## Geo (Aug 21, 2014)

Solar, that has been awhile back. I may be a bit off (I am getting old) but from the bottom, they look like VGA chips (north/south bridge). It may not be, I can't see the tops. If I had to give an opinion (I don't but I will anyway), the unusually high gold reported was because it is a VGA chip and not RAM chips.


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## solar_plasma (Aug 21, 2014)

You are right and I could be completely wrong, but the functions are lying within the PM-free die. What counts, is number, thickness and length of the bond wires per weight of garbage.


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## g_axelsson (Aug 21, 2014)

I agree with Solar, it is the type of package that decides if there is a lot of gold or not, not the function of the device. We should concentrate on the package, not the function.

Some earlier postings I've done on the same topic.
http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=34&t=20267#p207312
http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=52&t=11827&start=280#p187975

Göran


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## Geo (Aug 21, 2014)

Actually, comparing VGA chips to ram chips is like comparing a Geo Metro to a Cadillac. Ram chips have iron that must be dealt with and VGA chips (black epoxy) contains only precious metal.


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## g_axelsson (Aug 21, 2014)

Geo, have you looked at the pictures of the first post? The first picture shows BGA capsules, the second TSOP and the third one SOJ. TSOP and SOJ uses lead frame technology while the BGA uses CSP (Chip Scale Package) and lead bond or wire bond.
Looking at page 21 and 27 in http://www.invensas.com/Company/Documents/Invensas_ASQED2011_MemoryPackagingChallenges.pdf shows the different types of connections.

One thing that Romix actually got right was that there seems to be two different types of chips, one brown and one green. Check page 21 and you see two different types of substrate, brown polyimide film used for lead-bonding and green covered polyimide film used for wire bonding. The lead-bonding is made by gold plated copper ribbon so it takes a lot less gold per package.
So the brown bottom BGA memory chips actually contains *LESS* gold than the green bottomed chips.

Göran


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## Claudie (Aug 21, 2014)

Very informative PDF Göran. 
Thank you for sharing.


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## solar_plasma (Aug 22, 2014)

As a side note: Since the die in SOJs, TSOPs and many other packages is placed in the center, I always wondered, if it would make sense to cut off the outer areas or to punch out the center with a pressing. I tried with a pressing that had a round bit with a spike in the middle, but unfortunately it smashed the whole of the chip, not much better than a hammer. I think the spike is the problem.

But basically cutting off the 2/3, that are garbage, could be a fine thing for those who only process small amounts. It would triple the yield per kg of prepared stuff.


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## rrantique (Sep 17, 2014)

Here is a picture of the gold bonding wire still attached to the end of a leg. This will give you some idea how small they are. I'm still not sure about how to recovery these little wires or the best way to crush the chips once burnt into ash. After screening off and panning I still find small parts with the gold wire in little parts of the chips and attached to the legs when viewed under a microscope. This make me think that a large amount of gold is going to get wasted.


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## richard2013 (Sep 26, 2014)

Hello All!

For the kovar pins or legs with still gold bonding wire still attach how do we best to remove them?


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## solar_plasma (Sep 26, 2014)

some useful answers:
http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=37&t=13418

Once I did a pound of legs in old Ap, I can not remember to have gotten any gold from this, maybe only enough to darken a filter. The solution tested negative, - still acidic and copper laden it went to my stockpot.


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## kurtak (Sep 28, 2014)

richard2013 said:


> Hello All!
> 
> For the kovar pins or legs with still gold bonding wire still attach how do we best to remove them?



Here is what I do

(1) remove magnetic legs (kovar) from chip ash with magnet (this also removes any magnetic heat spreaders which are silver plated)

(2) put in 4 liter beaker 

(3) cover with HCL & add some D-water

(4) put beaker on hot plate in fume hood with watch glass on top (watch glass used to reduce acid/water lost to evaporation)

(5) bring acid/water up to simmer type boil 

(6) let simmer till base metals are dissolved (about 24 hours depending on batch size)(add D-water as needed due to evaporation)

(7) filter/wash remaining solids

(8) dry & incinerate (incinerate to rid trace acid & oxidize trace BMs)

(9) add to other low grade stuff like incinerated filters, incinerated ink cartridge mylar, etc.

(10) smelt with silver as collector metal

(11) re-melt with silver cement when making anode bars

(12) run in silver cell

Any gold that was dragged out of the ash when removing magnetic material from the ash (which includes heat spreaders &/or legs) is then recovered from the anode slims --- this also recovers the silver plating from the heat spreaders - so no values are lost

Kurt

Edited - to correct messed up step numbering


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## shaftsinkerawc (Sep 28, 2014)

Is step 3 proprietary?


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## Barren Realms 007 (Sep 28, 2014)

shaftsinkerawc said:


> Is step 3 proprietary?



It's a secret. If he tells you he will have to send a hit team after you. :twisted:


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## shaftsinkerawc (Sep 28, 2014)

Thanks, Tell him to send my reprief as it's getting colder here by the day.


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## kurtak (Sep 28, 2014)

opps  my bad - step 4 is actually step 3 step 5 is actually step 4 & so on - will go edit it now  

Kurt


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## richard2013 (Sep 29, 2014)

Thank you Kurt


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## Romix (Sep 29, 2014)

What about smallest chip on RAM boards.
Any gold inside?


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## Anonymous (Sep 29, 2014)

Can I ask the purpose of adding distilled water as opposed to tap water to the HCl please Kurt?


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## richard2013 (Sep 30, 2014)

spaceships said:


> Can I ask the purpose of adding distilled water as opposed to tap water to the HCl please Kurt?



I guess its because tap water has mixed chlorine and will make a weak HCL+CL when mixed with HCL that will dissovled gold.


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## kurtak (Sep 30, 2014)

richard2013 said:


> spaceships said:
> 
> 
> > Can I ask the purpose of adding distilled water as opposed to tap water to the HCl please Kurt?
> ...



Because I live in the country so have a well & here in the area where I live we have a real problem with iron bacteria http://en.wikipedia.org/wiki/Iron_bacteria in the water - so in order to somewhat control this problem we have to dose the well everyday with chlorine tablets - so yes there is the possibility of dissolving some gold

But also because the chlorine tablets don't eliminate the problem (they only control the problem to a point) & because the problem is microbial what happens - depending on several factors like when after the chlorine tablets are added to the well or how much water is used after adding it - it cause's a problem for me in the lab

one problem is that when I put my tap water in a beaker & apply heat - even with acid in the mix - the heat cause's the iron "bacteria" to coagulate & precipitate out leaving me with the brown gelatinous slime mentioned in the wiki link - thereby contaminating what ever I am working on - this precip problem could be just a little or "a lot" again depending on when &/or how much water has been used 

So I use D-water for everything I my lab & I tend to forget that tap water can be used in a situation like this

Kurt

Edit - to add from Wiki - "Treatment of heavily infected wells may be difficult, expensive, and only partially successful." --- this is my problem & a problem in general in the area I live


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## Erceg (Oct 7, 2014)

You can get rid of chlorine from water simply by allowing it to sit a while. Because there is no chlorine in the air and air is infinite (for this purpose) by diffusion all chlorine should go out of water. As for bacteria problem, I heard there are some filter papers that can filter them out. Find out the bacteria size and try to find filter paper with smaller pores. I newer seen or done, so I don't know how fast it will go or if it is more practical to just use distil water.


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## solar_plasma (Oct 7, 2014)

@kurtak

Very interesting, never heard of it. I wonder, if strong aeration followed by a sand filter (gravity or pool filter) and finally an active carbon filter wouldn't solve your problem? A pool sand filter has a back wash function and maybe the carbon can be reactivated to some degree by glowing.


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## SCB (Oct 10, 2014)

Erceg said:


> You can get rid of chlorine from water simply by allowing it to sit a while..



Unless the water is chlorinated with Chloramine which can’t be vented/agitated off. 
I don’t know about other countries but Chloramine is a quite common water treatment in Sweden


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## solar_plasma (Oct 10, 2014)

Wouldn't chloramine be caught by good quality activated carbon? I would assume so.


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## MarcoP (Oct 10, 2014)

Source: http://en.m.wikipedia.org/wiki/Chloramine


> Activated carbon have been used for chloramine removal long before catalytic carbon became available; Standard activated carbon requires a very long contact time, which means a large volume of carbon is needed. For thorough removal, up to four times the contact time of catalytic carbon may be required.
> 
> Most dialysis units now depend on granular activated carbon (GAC) filters, two of which should be placed in series so that chloramine breakthrough can be detected after the first one, before the second one fails.[17] Additionally, sodium metabisulfite injection may be used during circumstances.[18]


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## kurtak (Oct 11, 2014)

solar_plasma said:


> @kurtak
> 
> Very interesting, never heard of it. I wonder, if strong aeration followed by a sand filter (gravity or pool filter) and finally an active carbon filter wouldn't solve your problem? A pool sand filter has a back wash function and maybe the carbon can be reactivated to some degree by glowing.



solar 

thanks for the interest & sorry for the delay in responding - right now I am very busy trying to get things done before the winter sets in both on the home front & with my PM recovery/refining operation - we have already had one snow fall here so the real winter is just around the corner

anyway - my problem with the iron bacteria (& the problem in this general area) is really, really bad - even in the local towns where they have the best of water treatment/filtering systems they can only control the problem to a point - if you take a glass of town/city water & set it on the counter it will look perfectly clear to start with but by the end of the day it will have a "slight" cloudy brown color to it & a precipitate will be settling on the bottom

When you live in the country with a well as I do (unless you want to spend a lot of money on a water treatment system) controlling the problem is more difficult then in the towns where they have good systems in place --- my problem goes something like this

in the morning dose the well with chlorinating tablets (by dropping directly down into the well - we use calcium hypochlorite tablets) so shortly after the tablets are added & for a period of time there after - depending on how much water is used & when (washing cloths, dishes, taking showers etc.) the chlorine will be very high - high enough that you can smell it let alone taste it --- in fact I have (& do) use it for leaching CAT combs (to dilute my HCL in the leach bucket) & if I use it early enough in the day it will start leaching the PGMs almost instantly before adding any bleach

there does come a point in time when the chlorine content becomes more dilute & the water is still relatively clear (probably exceptable to use in the lab) but again that depends on water used &/or time lapsed - which is really a guessing game

later in the day (again depending on water used &/or time lapsed) as the chlorine becomes more & more dilute the water starts becoming an orange/brown in color which is when I start to have the problem of the iron bacteria coagulating & precipitating out contaminating solutions

we do have two paper cartage filters in line - but again they only help to control the problem to a point & yes I have tried using activated carbon filters as well but they don't last long & need replacing often & it gets quite spendy 

I am a member of a local co-op & if I buy my D-water in bulk (10 or more cases - 6 gallons per case) they knock 10 cents off per gallon so I only pay 69 cents a gallon

I do use tap water in the lab --- just never for dissolving metals because of the well water problem

Kurt


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## Geo (Oct 11, 2014)

Kurt, from your description, you can boil the water in a clean stainless steel pot and then cover and let everything settle. Use the clean, boiled water from the top without disturbing any sediment. You could also add a small amount of sodium hypochlorite bleach before the boil just to be sure. The boiling will help remove the chlorine.


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## kurtak (Oct 12, 2014)

Geo said:


> Kurt, from your description, you can boil the water in a clean stainless steel pot and then cover and let everything settle. Use the clean, boiled water from the top without disturbing any sediment. You could also add a small amount of sodium hypochlorite bleach before the boil just to be sure. The boiling will help remove the chlorine.



Yes this is actually a solution to the problem & works --- but more often then not my decision to process something low grade like the magnetic legs from incinerated chips is a spur of the moment thing like - hmmmm - today I don't have anything else going in the lab & I am going to be busy with other things all day so lets put the legs on the hot plate & let it do its thing - so its just more convenient to grab a jug of D-water pop the top - add - & move on --- just kinda got to be a convenient/habit thing - unless I wanted to take time to boil, let settle, fill jugs & clearly mark jugs ahead of time

I do "a lot" of silver so I buy D-water in bulk & relatively cheap -so back to spaceships original question of why D-water instead of tap water - its because I have a problem with my tap water so I use D-water & tend to forget that tap water can be used in some situations

Kurt


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## kurtak (Oct 12, 2014)

this is to show how bad the water is - it does this to white clothing, dishes, the inside of the dish washer, the cloth washer & is hard on water heaters

Kurt

Edit to say --- & this is after chlorination & 2 inline filters


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## macfixer01 (Oct 12, 2014)

Have you tried flocculation? For a test you could try a little Alum. It's used in making pickles I know, so is generally found in the spice aisle of almost any grocery store.

http://youtu.be/5uuQ77vAV_U

macfixer01


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## Martijn (Oct 15, 2014)

Kurt, apart from all the work of cleaning your well water for refining, just for normal use, I know silver was used in the past to keep wells fresh and free of bacteria. Since you are refining silver, maybe test a gallon with a small piece of silver to see if it kills the iron bacteria? It could be benefitial for health reasons of you and your family.
edit: added link:
http://arstechnica.com/science/2013/06/silver-bullets-that-kill-bacteria-not-werewolves/

from the text: 
"Next, silver interferes with how bacteria use iron. Iron is often held in place within proteins by binding to sulfur. Since silver also interacts with sulfur, it blocks the iron from doing so."


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## Geo (Oct 15, 2014)

I have also studied on how to safely store drinking water for long term storage. Apparently it is a well known fact that silver chloride is used to store drinking water for long periods. The silver chloride slowly oxidizes depleting the water of oxygen plus, silver is naturally antimicrobial and antiviral. You could use a small perforated canister full of silver chloride on a rope or small stainless chain lowered to the bottom of the well. You would need to pull it up perhaps once a year and either replace the silver chloride with fresh stock or process the old and make fresh silver chloride from that.


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## kurtak (Oct 16, 2014)

macfixer01 said:


> Have you tried flocculation? For a test you could try a little Alum. It's used in making pickles I know, so is generally found in the spice aisle of almost any grocery store.
> 
> http://youtu.be/5uuQ77vAV_U
> 
> macfixer01



Hmmmm --- so would Alum work in acidic solutions for dropping out those nasty colloids :?: 

Kurt


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## galenrog (Oct 16, 2014)

I remember the grey laundry and the reddish ring around tubs and sinks when I was young. It is still a problem in most parts of western Oregon, to include municipal supplies in my little town. To combat this in the lab I use ONLY distilled water. By doing this I eliminate the additional step of determining what my water source should be for any particular process. Yes, there is a cost. The cost of making a mistake regarding water source is far higher.


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## macfixer01 (Oct 16, 2014)

kurtak said:


> macfixer01 said:
> 
> 
> > Have you tried flocculation? For a test you could try a little Alum. It's used in making pickles I know, so is generally found in the spice aisle of almost any grocery store.
> ...




I don't know, but Alum was just the example used in the video. Besides commercial products there are some other common substances you can try like Bentonite or corn starch.
Here is some more information on flocculants. It mentions Guar Gum is used in an acid medium.

http://www.flocculants.info


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