Process for optimizing the process of copper electro-winning and electro-refining by superimposing a sinussoidal current over a continuous current

Abstract

This invention discloses a process of the electro-winning of metals, in particular copper, is done in a strongly acidic aqueous solution (˜180 gpl H 2 SO 4 ), with permanent cathodes of stainless steel or Cu starting sheets, and Pb—Ca—Sn anodes, in tradition electrolysis cells to obtain copper cathodes wherein in the electrolytic cells, a sinusoidal current is super-imposed over the continuous current in order to produce high-purity electrolytic copper. This invention also discloses the electro-refining process of metals, in particular copper, is done in a strongly acidic aqueous solution (˜180 gpl H 2 SO 4 ), with permanent cathodes of stainless steel or Cu starting sheets, and anodes of impure copper from founding, in traditional electrolysis cells in order to obtain copper cathodes wherein in the electrolytic cells, a sinusoidal current is super-imposed over the continuous current in order to produce high-purity electrolytic copper.

1 . The process of the electro-winning of metals, in particular copper, is done in a strongly acidic aqueous solution (˜180 gpl H 2 SO 4 ), with permanent cathodes of stainless steel or Cu starting sheets, and Pb—Ca—Sn anodes, in tradition electrolysis cells to obtain copper cathodes wherein, in the electrolytic cells, a sinusoidal current is super-imposed over the continuous current in order to produce high-purity electrolytic copper.  
   
   
       2 . The electro-refining process of metals, in particular copper, is done in a strongly acidic aqueous solution (˜180 gpl H 2 SO 4 ), with permanent cathodes of stainless steel or Cu starting sheets, and anodes of impure copper from founding, in traditional electrolysis cells in order to obtain copper cathodes wherein, in the electrolytic cells, a sinusoidal current is super-imposed over the continuous current in order to produce high-purity electrolytic copper.  
   
   
       3 . The electro-winning process, according to  claim 1 , wherein the sinusoidal current applied in the electrolytic cells has an amplitude greater than 400 A/m 2  and a frequency greater than 1,000 Hz.  
   
   
       4 . Electro-refining process according to  claim 2 , CHARACTERIZED because the sinusoidal current applied in the electrolytic cells has an amplitude greater than 400 A/m 2  and a frequency greater than 1,000 Hz.  
   
   
       5 . Electro-winning process according to  claim 1 , wherein the solution entering the cells operates with temperatures lower than 40° C., with Cu 2+  concentrations lower than 30 gr/l, and with flows lower than 240 l/min/cell when the amplitude of the frequency of the super-imposed AC current signal at the continuous current level is DC≧300 A/m 2 .  
   
   
       6 . Electro-refining of copper according to  claim 2 , wherein the operating variables that can be manipulated externally (e.g., concentration of cupric ions in the solution exiting the cells, electrolyte temperature, electrolyte flow to the cell) are established in function of the amplitude and frequency of the AC current signal super-imposed over the continuous current level (DC≧300 A/m 2 ) imposed on the copper electro-refining process.