Extract gold from motherboards

Today you will learn how to get the gold out of old motherboards with their own hands. Please note: chemicals that are used in the demonstration, very dangerous, especially when combined concentrations. Therefore we do not recommend repeating this experiment at home.





Gold is present in many elements of the motherboard: connectors IDE, slots, PCI Express, PCI, AGP, ISA, and other ports, bridges, in the CPU socket and slots DIMM (SIMM on older motherboards). All these connectors are often coated with a thin layer of gold in a thickness of several microns.

Tools



Tools & quot; title = «Gold is present in many elements of the motherboard: connectors IDE, slots, PCI Express, PCI, AGP, ISA, and other ports, bridges, in the CPU socket and slots DIMM (SIMM on older motherboards). All these connectors are often coated with a thin layer of gold in a thickness of several microns.

Tools »& gt;

The first stage of our experiment is to remove all of these contacts and connectors. We will need wire cutters, pliers and cutters, flat and Phillips screwdrivers, as well as a certain amount of time.



For the experiments need a large number of contacts - they just gave our "donor" motherboards.



We also need chemicals and tools.

Electrolysis



To get a few micrograms of gold deposited on the contacts, we need an electrolytic cell. In the bath is poured 95% concentrated sulfuric acid. The cathode is made of lead anode - of copper. Contacts (raw materials) are connected to the anode, which we have done in the form of baskets.



When we passed through the cell electric current (we used conventional battery charger) copper anode (and contacts) is dissolved and deposited on the cathode of the lead. Gold is not associated with the copper, forming sediment at the bottom of the cell. It should also be noted that during this process the temperature of the bath is significantly increased.



After gold was separated from the contacts need to allow time for the bath to settle. Then must be removed as much as possible of sulfuric acid, then it is possible to start the dissolution of residues on the bottom of the electrolytic cell.

Dilution



Be careful and always empty the acid to water and not vice versa! If you make a mistake, the first water droplets which come into contact with sulfuric acid immediately evaporate and the acid may then dripped.



We had a sulfuric acid solution of different metals (including gold) and waste that should be filtered. Why not filter the acid directly, without diluting it? Just for the reason that paper filters will not stand in front of concentrated sulfuric acid.

Dissolution



In the filter will be a mixture of different metals and waste. Now we all soluble in this mixture of 35% hydrochloric acid and 5% chlorine bleach (sodium hypochlorite) in a ratio of 2: 1. 2 HCl + NaClO - & gt; Cl2 + NaCl + H2O



Cl2 + NaCl + H2O & quot; title = «In the filter will be a mixture of different metals and waste. Now we all soluble in this mixture of 35% hydrochloric acid and 5% chlorine bleach (sodium hypochlorite) in a ratio of 2: 1. 2 HCl + NaClO - & gt; Cl2 + NaCl + H2O "& gt;

Be careful! This reaction is exothermic, it leads to the release of chlorine gas is very dangerous. Chlorine is used as a chemical weapon in the First World War.



Actually chloro that stood by mixing hydrochloric acid and chlorine bleach, we will just use for dissolving gold in a gold chloride III. 2 Au + 3 Cl2 - & gt; 2 AuCl3

Again filtering



Now we need to filter again. Filter will delay all wastes, leaving only the solution of gold chloride III.

Deposition



To obtain gold metal, we need to precipitate in the solution. For this purpose, we will use the powdered sodium metabisulfite. In the presence of water gives the sodium metabisulfite, sodium bisulfite. Na2S2O2 + H2O - & gt; 2 NaHSO3 This sodium bisulfite will allow us to precipitate the gold. 2 NaHSO3 + 3 AuCl3 + 3 H2O - & gt; 3 NaHSO4 + 6 HCl + 2 Au



2 NaHSO3 This sodium bisulfite will allow us to precipitate the gold. 2 NaHSO3 + 3 AuCl3 + 3 H2O - & gt; 3 NaHSO4 + 6 HCl + 2 Au "title =» To get the gold metal, we need to be precipitated in the solution. For this purpose, we will use the powdered sodium metabisulfite. In the presence of water gives the sodium metabisulfite, sodium bisulfite. Na2S2O2 + H2O - & gt; 2 NaHSO3 This sodium bisulfite will allow us to precipitate the gold. 2 NaHSO3 + 3 AuCl3 + 3 H2O - & gt; 3 NaHSO4 + 6 HCl + 2 Au & quot; & gt;
We need to give solution to settle, and then we get gray powder on the bottom of the beaker. Do not lose any grains - is a metallic gold!

Melting



Now we need to melt the powder in the crucible. The melting point of gold is 1064 ° C, so we need an oxygen-butane burner.



As a result, we get a nice golden pellet! Can we call our process economically feasible? Definitely not. It only makes sense in the industrial scale. A small pellet of gold, which we received, it is worth only two or three dollars at current prices. And, frankly, the company that extract gold from old computers, use of technology and other chemicals that are even more dangerous. But, you see, it is still interesting to know that you can get gold from the motherboard at home. You can also get gold from expansion cards, processors and chipsets.

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