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How to Remove Gold from Plated Materials Including Electronics, Computer, Telecommunication and Other Salvage and Scrap Material This is an update to the Home Based Salvage & Recycling Business Manual. Check here for more information: http://www.recyclingsecrets.com/home-based-salvage-recycling-business- manual.htm Disclaimer and Warnings Sulfuric acid (H 2 SO 4 ) is a poisonous, corrosive substance. Because of the health and environmental risks associated with any chemical use I strongly recommend that you do not do this yourself. If you do go ahead and do this on your own, please understand that you do so at your own risk. Please check out the health risks to yourself and your family and risks to the environment. Also, be sure to wear the proper clothing including acid proof gloves, apron and facemask. Also wear a respirator that protects from chemical fumes – sulfuric acid especially. You will also need a ventilation system. There are links to scrubbers for ventilation, safety equipment and related items at the end of this report. Here is a link to some of the health effects of sulfuric acid: http://www.atsdr.cdc.gov/phs/phs.asp? id=254&tid=47 Copyright © 2010 Michael R. Meuser, All Rights Reserved 1

How to Remove Gold from Plated Materials Including Electronics, Computer, Telecommunication and Other Scrap

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Describes a low tech method for removing gold from plated material found in electronic, computer, telecommunication and other scrap and salvage.

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Page 1: How to Remove Gold from Plated Materials Including Electronics, Computer, Telecommunication and Other Scrap

How to Remove Gold from Plated Materials Including Electronics, Computer, Telecommunication and Other Salvage and Scrap Material

This is an update to the Home Based Salvage & Recycling Business Manual. Check here for more information:

http://www.recyclingsecrets.com/home-based-salvage-recycling-business-manual.htm

Disclaimer and Warnings

Sulfuric acid (H2SO4) is a poisonous, corrosive substance. Because of the health and environmental risks associated with any chemical use I strongly recommend that you do not do this yourself. If you do go ahead and do this on your own, please understand that you do so at your own risk. Please check out the health risks to yourself and your family and risks to the environment.

Also, be sure to wear the proper clothing including acid proof gloves, apron and facemask. Also wear a respirator that protects from chemical fumes – sulfuric acid especially. You will also need a ventilation system. There are links to scrubbers for ventilation, safety equipment and related items at the end of this report.

Here is a link to some of the health effects of sulfuric acid:

http://www.atsdr.cdc.gov/phs/phs.asp?id=254&tid=47

Finally, check with your local public health and environmental departments about the use of sulfuric acid. Also, be sure to take steps to safely and legally dispose of any waste.

Plated Gold

This system removes gold that is plated on an electrically conductive substrate such as copper or brass. It will not work for things such as gold inside electronic devices, gold plated fingers on circuit boards and the like. In a subsequent report I’ll address these other types of gold bearing items, their approximate values and ways to get at the gold.

Copyright © 2010 Michael R. Meuser, All Rights Reserved 1

Page 2: How to Remove Gold from Plated Materials Including Electronics, Computer, Telecommunication and Other Scrap

Gold Plating Removal System

This relatively simple system will recover up to about 1/4 ounces of very fine gold per hour depending on material.

Equipment and Supplies

The power supply is a 6-12 volt 60 ampere battery charger. The 6 volt setting provides the approximately 8 volts required. I fabricated the basket out of copper wire that I salvaged. If you do not have any on hand copper grounding wire can be had at most any hardware store. The cathode also came from my salvage pile. If you do not have any large chunks of copper, a local metal scrap yard should sell you a piece. For mine I used a 2”x2”x1/4” piece of copper buss bar. I haven’t tried it, but I would think that a flattened piece of larger copper tubing would work as well.

Material

All of the gold plated material must be electrically conductive. By that I mean that the gold must be plated on metal and all the pieces in the basket must contact one another. This works best with gold plated jewelry, silverware, coaxial connectors, edge connectors for circuit boards and the like. Material like this (fig.2) must have the plastic removed first.

Copyright © 2010 Michael R. Meuser, All Rights Reserved 2

Page 3: How to Remove Gold from Plated Materials Including Electronics, Computer, Telecommunication and Other Scrap

For smaller items like gold plated connector pins I put a piece of copper or brass screen as a sort of sock inside the wire basket.

Operation

First off, make sure you are using only sulfuric acid. Many people think that the only way to remove gold is with aqua regia – this is not the case. As aqua regia works, it dissolves ALL of the material into solution so most of it is used up dissolving metal substrate not gold. The aqua regia process uses large quantities of acids and is very dangerous. Another problem with using aqua regia is that the base metal is no longer available as scrap – a secondary revenue stream is lost. This system for removing gold plate (fig. 1) uses relatively small amounts of sulfuric acid and it is reusable to boot.

I use a plastic bucket filled with 1 gallon of sulfuric acid. The bucket is then placed in a plastic wash tub filled with cold water. The temperature of the acid should not be more than 100 degrees farenheit. I have found that this small system will run for several hours at less than 100 degrees farenheit with only cold water in the wash tub before having to add any ice to reduce the temperature.

I fill the copper basket with gold plated material, place it in the bucket full of sulfuric acid and connect the anode (the basket) to the positive lead and the cathode (block of copper in bottom of bucket) to the negative lead from the battery charger. I then turn on my fume hood and make sure I have all of my safety equipment in place and then I turn on the battery charger.

When I stripped very heavy plated material it would take ½ to a full hour to remove 1/8 ounce of gold. Thinner plated material will take less time and, of course, yield less gold.

I can tell when the gold is removed by watching the ammeter on the charger. When I see it drop to near zero I know that I’m almost there. I give the basket a couple of shakes and the meter pops back up for a minute or two and then goes back to near zero. I repeat this shaking process a couple of times. You will notice that there is a dark brown sludge at the bottom of the bucket. This is the gold plus some copper and other materials.

If you have more material to de-plate, remove the basket from the bucket, dump the basket into another bucket. Then fill the basket with new material and start the process again.

Copyright © 2010 Michael R. Meuser, All Rights Reserved 3

Page 4: How to Remove Gold from Plated Materials Including Electronics, Computer, Telecommunication and Other Scrap

Once done with the batch or batches it’s time to recover the gold. First, wash the material you’ve been working with in a 1:1 diluted water and sulfuric acid solution. Use it sparingly – just enough to remove any residue from the de-plating process. You are washing off some of the gold sludge that has accumulated on the material rather than precipitating to the bottom of the bucket. Add this cleaning solution to the bucket.

Pour the sulfuric acid de-plating solution and sludge into two large glass beakers and boil it. After 5 hours the sulfuric acid will be clear and yellowish or greenish if some copper was dissolved. At the bottom of the beakers you will see a spongy coagulated mass. This is near pure gold. Be sure to boil this under your exhaust hood and wear a respirator. During the first couple of hours the boiling is producing sulfur dioxide.

The next step is to allow the solution to cool. This can take up to 12 hours for it to reach room temperature. Once cool pour off the solution for later reuse or disposal and place the spongy material in a vacuum filter. Once the spongy material is dry, it can be melted in a crucible. You can add a little saltpeter (Potassium Nitrate KNO3) as it is melting to improve the purity. Saltpeter is available in garden stores and departments as a stump remover or you can get it from a chemical supply house.

Safety Equipment and Helpful Products

I’ve created a web page listing various safety equipment and supplies that I have mentioned in this report. Check here for more information:

http://www.recyclingsecrets.com/salvage-recycling-products.htm

Home Based Salvage and Recycling Business Manual

This is an update to the Home Based Salvage and Recycling Business Manual. I have written this because many have requested it, but I do recommend that you do not process your gold bearing scrap yourself unless you truly do have professional experience and equipment.

Gold bearing electronic, computer and telecommunication scrap is not the only place to find gold. In the manual you will learn about how to bootstrap your business, finding the materials and equipment you need to startup for

Copyright © 2010 Michael R. Meuser, All Rights Reserved 4

Page 5: How to Remove Gold from Plated Materials Including Electronics, Computer, Telecommunication and Other Scrap

little or no cash. You will also learn about other things to salvage that are worth as much or more than gold. Check it out!http://www.recyclingsecrets.com/home-based-salvage-recycling-business-manual.htm

Mike Meuserhttp://www.recyclingsecrets.com

P.S. You are free to share this document in any manner that you wish as long as you do not change the contents in any way or form.

Copyright © 2010 Michael R. Meuser, All Rights Reserved 5