METHOD FOR CONTINUOUSLY ANNEALING AND PICKLING COPPER OR COPPER ALLOY

PURPOSE:To simply remove oxide scale from continuously annealed copper (alloy) at a low cost without reducing the thickness of the base metal, by pickling the copper (alloy) with a cupric chloride soln. CONSTITUTION:In a line for continuously annealing and pickling copper (alloy), annealed copper (alloy) is pickled with a cupric chloride soln. as a pickling soln. in each pickling tank. When the copper alloy is phosphor bronze or the like forming a tough oxide film, the annealed copper alloy is preferably prewashed with an alkali soln. contg. an alkali metal or an alkaline earth metal or one or more of aq. sulfate and persulfate solns. each contg. ammonium ions before pickling by the above-mentioned method. Oxide scale produced by annealing in the air is simply removed and copper (alloy) having little residual scale is stably obtd. Cupric chloride can be simply regenerated in the pickling soln. by blowing chlorine. Since the pickling soln. has weak etching power to unoxidized copper, the thickness of the base metal is hardly reduced.