DEVELOPMENTS IN MANUFACTURE OF COPPER WIRE 197 



The coils of rod after pickling are thoroughly washed with lake 

 water ^ at a pressure of about 70 pounds per square inch to remove loose 



Fig. 9 — Electrolytic recovery of copper from rod mill pickling solution 



copper dust and acid, and then immersed in an alkaline fat solution to 

 neutralize any trace of acid and to provide a protective coating against 

 oxidation until converted into wire. 



Wire Mill 



The coils, after being pickled and washed, are carried by monorail 

 cranes to the wire drawing machines where they are converted into wire 

 of the desired size. The dies used in the heavy wire drawing machines 

 are pulled into place at the starting end of the coil of rod on a die 

 stringing machine (Fig. 10). The coil, w4th dies strung into position, 

 is then placed in a heavy wire drawing machine. 



The heavy gauges of wire, such as line wire, are drawn with one 

 set-up on this machine; medium sizes, used in lead covered cable, are 

 made by taking the wire as it comes from the heavy machine and re- 



' Lake water is relatively free from mineral salts which would corrode the rod and 

 affect the wire drawing compound. 



