Method for obtaining a good contact surface on an electrolysis cell busbar and busbar

Abstract

The invention relates to a method for forming a good contact surface on an electrolysis cell busbar used in the electrolysis of metals. The contact surface of the busbar i.e. the surface onto which the support bar or lug of the electrode to be immersed in the cell is lowered, is coated with a highly electroconductive metal. The invention also relates to an electrolysis cell busbar, on the surface of which a highly electroconductive coating is formed.

1 . A method for forming a good contact surface on an electrolysis cell busbar used in the electrolysis of metals, where at least the surface of the bar is made of copper and the contact surface forms an area on to which an electrode is lowered, comprising, forming on the copper contact surface of said busbar a transmission layer, coating the contact surface with silver or silver alloy using soldering or thermal spraying technique, wherein the coating material forms a metallurgical joint with the copper and the transmission layer.  
   
   
       2 . The method according to  claim 1 , wherein the transmission layer is tin or a tin-dominant alloy.  
   
   
       3 . The method according to  claim 1  or  2 , wherein the silver alloy is silver-copper.  
   
   
       4 . The method according to,  claim 1 , further comprising, equipping the electrolysis cell with a potential balancing bar, forming on the copper surface of said potential balancing bar a transmission layer coating with silver or silver alloy, wherein the coating material forms a metallurgical joint with the copper and the transmission layer.  
   
   
       5 . The method according to,  claim 1 , wherein the busbar is continuous in the longitudinal direction, thereby forming a coating layer along the whole length of the busbar.  
   
   
       6 . The method according to,  claim 1 , further comprising notching or grooving the contact surfaces of the busbar onto which the electrode is lowered, and forming the coating layer is formed on the notched or grooved areas of the busbar.  
   
   
       7 . The method according to  claim 1 , wherein the thermal spraying technique is based on gas combustion.  
   
   
       8 . The method according to  claim 1 , wherein the thermal spraying technique is high velocity oxy-fuel spraying.  
   
   
       9 . The method according to,  claim 1 , wherein the coating material is highly electroconductive and in powder form.  
   
   
       10 . The method according to  claim 1 , wherein the thermal spraying technique is flame spraying.  
   
   
       11 . The method according to  claim 1 , wherein the coating material is highly electroconductive and in wire form.  
   
   
       12 . The method according to,  claim 1 , wherein the contact surface is subjected to heat treatment after coating.  
   
   
       13 . An electrolysis cell busbar for use in the electrolysis of metals, whereby at least a surface section of the busbar is made of copper and a contact surface forms an area onto which an electrode is lowered, wherein the contact surface of the busbar comprises a transmission layer, and the contact surface has been coated with silver or silver alloy using soldering or thermal spraying technique, wherein the copper, transmission layer and coating material have formed a metallurgical joint.  
   
   
       14 . The busbar according to  claim 13 , wherein the transmission layer is tin or a tin-dominant alloy.  
   
   
       15 . The busbar according to  claim 13  wherein the silver alloy is silver-copper.  
   
   
       16 . The busbar according to  claim 13 , wherein the busbar is continuous in the longitudinal direction, wherein the coating layer is formed along the whole length of the busbar.  
   
   
       17 . The busbar according to  claim 13 , wherein the busbar contact surfaces onto which the electrode is lowered, are fabricated by notching or grooving, wherein the coating layer is formed on the notched or grooved areas of the busbar.  
   
   
       18 . The busbar according to  claim 13 , wherein the busbar is a potential balancing bar.