Gold Extraction & Recovery from Intel Pentium Pro CPUs – Part 1

Alexander Buck

The question of how much gold may be found inside electronics is one that I've seen asked on various occasions, and happened to pique my interest. In that case, how much gold is inside electronics? This guide aims to answer this question, but also provide detailed instructions on how to safely engage in the gold recovery process through experimentation with two Intel Pentium Pro CPUs.

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Entering the world of gold recovery can be a bit confusing and misleading in the very beginning. For someone unfamiliar with gold recovery, an individual will face many different types of methods to ultimately carry out the same result with similar yields. The primary difference between these methods is how long the process takes overall, but also the safety of the individual engaging in the process. We will be focusing on one process in particular that tends to be a bit safer and straightforward.

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Multiple websites out on the internet make various claims of the amount of gold found inside certain CPU models, such as OzCopper. For example, OzCopper claims an Intel Pentium Pro CPU has a gold content of about 1g, but after doing a bit of research, on Gold Refining Forum, according to multiple users, as well as other sources, these gold content lists and websites tend to contain false information. In this case, the takeaway is that if you're interested in trying gold recovery for yourself, and are interested in potentially profiting from the process, make sure to do a hefty amount of research beforehand.

OzCopper CPU Gold Content List

For this demonstration, I have opted to use two Intel Pentium Pro CPUs as test subjects as these are widely known to contain a large amount of gold compared to other CPUs, if not the most, but also to prove whether or not the users on Gold Refining Forum or the numbers OzCopper have reported are correct.

Precautions & Chemicals

Do not attempt any actions described within this article unless prepared with proper safety equipment and materials.

The chemicals required for gold recovery are highly toxic and produce numerous health risks, therefore, they should be handled with care in a well-ventilated area, preferably outdoors, to avoid injury. Safety equipment required is as follows.

  • Respirator: Required to prevent inhalation of chemical fumes.
  • Rubber Gloves: Required to prevent chemical contact with skin.

Again, the following chemicals should be handled with care to avoid injury.

For gold recovery, there are various methods, but we'll be focusing on a specific two methods both using different chemicals, each with their own benefits and drawbacks, but if done right, both methods should result in similar yields.

Gold Recovery Materials

Method 1:

  • Concentrated Muriatic Acid/Hydrochloric Acid
  • 3% Hydrogen Peroxide
  • Clorox Bleach
  • Sodium Metabisulfite

Method 2:

  • Concentrated Muriatic Acid/Hydrochloric Acid
  • 3% Hydrogen Peroxide
  • Nitric Acid
  • Urea (Optional, but recommended.)
  • Sodium Metabisulfite

For Step 1, both methods are identical and involve a 2:1 ratio of Muriatic Acid/Hydrochloric Acid and 3% Hydrogen Peroxide, but step two differs with two separate variants of a chemical solution known as Aqua Regia.

Aqua Regia

  • Muriatic Acid/Hydrochloric Acid mixed with small doses of Clorox Bleach
  • 3:1 ratio of Muriatic Acid/Hydrochloric Acid and Nitric Acid
    • This solution has an optional neutralization step using Urea in step two.

Step 1 - Separation Stage

To start, we'll use a bit of rubbing alcohol to clean any remaining thermal compound from the CPUs. An optional, but highly recommended step is to remove the ceramic plate on the bottom of the CPUs to expose the gold wiring connecting the CPU die to the ceramic packaging and pins. This can be done through heating the processors with a blowtorch, cracking the heatspreader with a screwdriver, or simply taking a hammer and breaking the CPUs into pieces, though this is not recommended as the filtering stage becomes more difficult due to additional ceramic debris.  This stage consists of mixing Muriatic Acid or Hydrochloric Acid and Hydrogen Peroxide in a 2:1 ratio. This ratio does not have to be exact, and the formula should contain enough chemical to fully cover the processors.

Intel Pentium Pro/AMD Ryzen Threadripper size comparison.
Pentium Pro CPUs - Front
Pentium Pro CPUs - Front
Pentium Pro CPUs - Back
Reaction begins to occur.

As soon as the solution makes contact with the CPUs, a reaction begins to occur. The solution will start to turn to a dull yellow and bubble every so slightly almost immediately, and over time, the solution will turn to a darker green. Depending on the volume of material, reaction time can vary. Various sources online have recommended to leave the solution sit for as little as 24 hours to as long as two weeks.

In Part 2, I'll detail my findings from Step 1, and move into Step 2 - creating Aqua Regia.

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