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Metals/Copper Refining


QUESTION: We have 100 kilograms of metal sheets-size 1 foot x 1 foot weight 5 kilos each. Twenty sheets in number. These sheets contain copper 80%  and tin and lead 19% Zinc 1%
We have a tank of  4x3 ft. And height 2ft.
We want to refine copper. My question is how much copper sulphate solution we should prepare for this, what voltage should we use and how many ampere rectifier is required for it?
How many anode sheets should we hang in our tank at one time according to the size of our tank, and what should be the distance between them? And how much time the refining process will take for these 20 sheets?

ANSWER: Dissolve copper sulfate to maximum saturation. Use dividers between cells (20). Use 0.5 amps per square decimeter surface on one side of the copper cathode (negative side). Use a per copper cathode that is thin.  Attach the negative cathode to the next anode (positive)in a tandem manner.  Leave one inch between anode and cathode.  Usually 24 hours to complete.

---------- FOLLOW-UP ----------

QUESTION: Thanks a lot for this reply.
Please also let me know how many kilowatt electricity connection and what capacity of rectifier do we require for it in terms of voltage and amperes?
Thanks & Regards

A square decimeter is approximately 4 square inches. Do your own math: 0.5 amps per.  0.5 volts per. Total the surface that submerges and divide by 4 square inches. The answer will give you total volts and amps. Only count one plate as the electricity passes through them all. Check the voltage/amperage with a meter. Increase the voltage to the 0.5 amp flow. 0.35 amps also works to give a purer product, but is much slower.


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Christopher Poe


The processing/refining of precious metals including chalcogenic ores like tellurides and selenides.


32 years experience in ore assaying and refining. Presently head chemist and chief refiner of a Philippine metals company.

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