I was just wondering about reverse electroplating. I know the basic process, submerge item in an electrolytic solution and hooked up as an anode, then a second piece of metal to act as the cathode and collector. After which power is supplied the anode metal is ionized and dissolved being deposited on the cathode. After some research I have concluded that stainless steel will be the best material to use as a cathode because it is unaffected by the electricity, whereas some metals react with the electrolytic solution.

My questions are, can any electrolytic solution be used such as salt water, instead of an acid or strange chemical mixture, and will the underlying metal beneath the plating be also plated on top of the cathode also?

Things that make me wonder this are as follows.

Salt contains sodium, I am not sure how it reacts with precious metals such as platinum or gold under these conditions. I don't want displacement reaction going on here.

I was reading something about the acid providing the correct ionic compositions to carry the plated item to the cathode.

I want the underlying item to be left as is, or with as little damage as possible.

If I can find a viable solution, I would use this as a good income source. I have found some 24k gold plated titanium rings on eBay. If I can separate the gold from the titanium, then I can make nearly 100% profit from initial purchase.

Stainless steel? Unaffected by electricity? Hardly.

The purpose of the electrolyte is to hold whatever species is to be plated at the anode, in solution. If the solution were too basic, as an example, certain metal ions would precipitate and fall to the bottom of the system, never to be heard from again.

Salt contains sodium. It is NOT going to react with most precious metals. In fact, it's presence would probably be necessary in the case of gold.

If you're going to deposit gold at the anode, the best anode material is... drum roll... gold! The cathode should be made of the impure materials -- not stainless steel. Also, the electrolyte will have to be such that gold will stay in solution (probably high in chloride since tetrachloroaurate salts are soluble.

You won't get 100% profit. There are plenty of costs in this. #1 is electricity, and it's not cheap in this case.

Stainless steel in an aqueous NaCl solution will not tarnish. I have used stainless steel rods while oxidizing Fe before. The object being that it itself will not react with the sodium ions, chlorine ions, or the H bubbles precipitating off it. I imagine the elecricity cost would be higher, however where I live, the amount is little.

We own a large 5 bedroom house, with partial electric heating, indoor dryer, operating welding equipment, air conditioning in the summer, and three refrigerators all rarely exceeding $50 monthly.

I have been schooled in electronics, and building a relatively high amperage rectifier is no problem, even at 150 volts. I would assume that certain acids would allow partial ionization of the gold, allowing for the electricity to work more efficiently. Nevertheless the gold does not adhere to stainless well, allowing it to be peeled off with ease. My main concern is whether it is possible with NaCl and whether the titanium under the gold plating would be plated as well, or dissolved, or remain untouched.

Maybe someone could explain to me how electroplating actually works, with a chemical equation. General materials would be preferred as opposed to exact composition. For instance, an inert metal in an electrolytic solution. Or one that behaves like aqua regia.

Electroplating - Wikipedia, the free encyclopedia

Electrowinning - Wikipedia, the free encyclopedia

With gold, you don't necessarily want aqua regia. Aqua regia contains both nitric acid (an oxidizing acid -- required to oxidize gold), and hydrochloric acid (source of chloride ions). Gold doesn't form Au(3+) ions, it forms AuCl4(1-), usually as HAuCl4 (with waters of hydration). The oxidation will occur at the cathode simply by removing electrons from the metal. The redeposition has to occur at the anode -- by adding reducing the gold (formally in the Au(3+) state). The chloride ions are simply spectator ions.

You can actually calculate the amount of electricity that is required for each gram of metal -- assuming 100% conversion. You need three electrons for each atom of gold you extract with this method.

Another way to extract gold from alloys is simply to dissolve it and precipitate it, then reduce it with carbon or electrolytically. I'm not sure. Gold might be able to be decomposed with heat and wouldn't need carbon. Gold is usually present in ores as the free metal (hence panning for gold was a fair way to mine for gold). Nowadays, they will use cyanide solutions to dissolve the gold. Obviously, that has its own dangers.

Cyanide or Cyanide-free gold plating solutions

The best method for obtainig very pure gold from such items is to dissolve off the gold plate in aqua regia ,filter and then pass sulphur dioxide gas into the solution. The gold ions are reduced to powdered gold and it it only needs fitering off and washing to give very pure metal powder.