[shphinx]

Hey friends, How is it possible to reduce copper I chloride which has a green appearance, to copper?

[lost and found]

If you can get CuCl2 instead of CuCl, electrolysis of aqueous CuCl2 will give you Cu and Cl2.
     

[shphinx]

I think I should explain more about the subject. To be more specific, I am going to remove the green copper chloride remained on some ancient copper objects. Do you know any special chemical substance that can dissolve it but mot the copper itself?!

[lost and found]

CuCl is white. CuCl2 is green. CuCl slowly oxidizes to CuCl2, which causes the green color. If the object is ancient, it should be mostly CuCl2. Sulfuric acid will react with CuCl2 but not with Cu.

H2SO4 + CuCl2 --> 2HCl + CuSO4

CuSO4 is blue and souble in water. The HCl will be given off as a gas. Watch out though, HCl is poisonous by inhalation and CuSO4 is poisonous when ingested.

[Borek]

If it is old and green, it is most likely not CuCl₂, but basic carbonate, something like Cu(OH)₂^.CuCO₃.

http://en.wikipedia.org/wiki/Patina

[shphinx]

Thank you so much friends for your suggestions. The kind of patina that I believe I am dealing with, is most likely a kind of chloride:
http://nautarch.tamu.edu/class/anth605/File12.htm
Since this is actually regarded as a bad kind of patina which is able to spread and corrode the whole material. Is the sulforic acid the best solution?

[lost and found]

If it is CuCl2, then hydrogen gas should replace copper since it's higher on the activity series.

CuCl2 + H2 --> Cu + 2HCl

If it's CuCO3 * Cu(OH)2, then heating it will break it down to black CuO, which would flake off when washed in water.

CuCO3 * Cu(OH)2 --> 2CuO + CO2 + H2O

MB

[shphinx]

Thank you so much again, I'll try that

[hmx9123]

Copper(I) chloride actually oxidizes to copper oxychloride for the most part.