![]() This further improves the deposit and makes it more uniform. In acid copper plating, which uses a very similar formula, air agitation is used. According to the patent, I think it can be run as low as 65% H2SO4, yet it neither dissolves or deposits copper, to any great extent. The deposit will probably look terrible, if it deposits at all. ![]() ![]() The solubility of the copper will be very low. Both the cathode and anode efficiencies will be quite low. I can see many problems with using the strong acid. That's 5-7 times stronger than what you should be using. What immediately caught my eye is that you're using 70% H2SO4, by volume. The efficiency of this bath is about 92-96%. I have also used iron-free blackstrap molasses or dissolved gelatin as a grain refinerĪt 100% efficiency, copper deposits at the rate of 1.185 gram/A-hr. You can probably get away without these additives, but the deposit will not be nearly as smooth and could be stressed. Their consumption is proportional to the number of amp-hours used and can be controlled by keeping track of the bath usage. They also prevent treeing of the deposit. The thiourea and glue act as grain refiners and are basically what will produce the smooth finish you're after. If I remember right, the bone glue is dissolved in hot water before adding. In general, here's a typical solution formulation and operating conditions. However, there is a ton of information on the internet. I haven't worked with it in a long time and didn't remember the exact operating conditions. If you want to do this right, you should start with a solution already made up in the following manner. I have deposited copper from this solution quite a few times. I haven't worked in a copper refinery, but I once spent a week in the Anaconda tankhouse, which, if I remember right, had 400, 600 gallon tanks. The problem is it won't stay that way for very long.Ĭyanide is also used to create a bright surface, but that is likely not a viable choice for you. You can achieve the nice copper color you described simply by using dilute sulfuric to clean the surface of copper. Coppper is not soluble in dilute sulfuric acid, but copper oxides are. Sorry, I don't have any technical information regarding voltage and acid concentration, but you should be able to find that information by searching for a copper parting cell online.Ī side note. Some refineries use a titanium starter sheet, from which the copper is pulled when the deposit is thick enough.Ī filter bag is generally placed over the anodes, where insoluble contaminants are collected (the anode "slimes", where the precious metals included in the copper are to be found after parting). Stainless sheet can function as the cathode, or a sheet of pure copper can be used instead. Contamination of the electrolyte leads to rapid degradation of the deposited copper, yielding copper sponge that falls off the cathode instead of adhering tightly.Ĭommon design is one whereby anode and cathodes are alternated on a rack system. It is, of necessity, made from cathode copper.Ī simple sulfuric cell is all that is required, but you must start with relatively pure copper at the outset. Unless it's a burning desire, you're far better served to simply use copper wire.
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