Determination of Copper in Lead and Lead Base Alloys

This work was undertaken in an effort to develop a rapid method for the determination of copper in the range of 0.01 to 0.06% in lead alloys and in the range of 0.001 to 0.005% in lead. A visual and a photometric method are suggested, based on the color developed by copper in concentrated hydrochloric acid. Iron interferes with the determination, but this interference is reduced by use of an aluminum file in the visual method, and is corrected for in the photometric method by determination of the Lron as the thiocyanate. The visual method is very rapid, is accurate to plus or minus 0.1% in the range 0.01-0.06%, and is suggested as a control method for alloys. The photometric procedure is accurate to better than 0.006% in the range of 0.01 to 0.05% and 0.0005% in the range 0.001 to 0.005%, and is suggested as a routine or control method