COPPER MATERIAL OF LOW SOFTENING TEMPERATURE FOR HIGH ELECTRICAL CONDUCTION

摘要

PURPOSE:To economize considerably the energy consumption required for annealing by rerefining pure copper such as electrolytic copper or the like to decrease the sulfur content thereof to a specific microtract amt. thereby decreasing the softening temp. thereof and reducing the annealing temp. and annealing time in the stage of working. CONSTITUTION:The number of annealing of raw material copper increases and heat energy for annealing increases with an increase in a reduction ratio in the stage of working electrolytic copper or the like having high electrical conductivity to a fine wire or foil. Pure copper such as electrolytic copper or the like is subjected to a reelectrolysis treatment with an aq. copper nitrate soln. as an electrolytic bath or to rerefining such as a zone refining method or a wet process of desulfurization using gaseous hydrogen, etc. to decrease the content of S to <=1ppm inner mol. Such extra low sulfur pure copper is considerably decreased in the softening temp. thereof as compared to electrolytic copper, etc. and since the annealing temp. and annealing time in the stage of working are reduced, less heat energy is required for annealing.