REGENERATION OF CUPRIC ETCHANTS AND RECOVERY OF COPPER SULFATE

摘要

PROBLEM TO BE SOLVED: To provide a cost-efficient process to reclaim a usable or marketable products such as copper sulfate and hydrochloric acid from spent chloride-based copper etchant solutions.;SOLUTION: Spent, acidic solutions comprising cupric chloride and hydrochloric acid from the copper etching process are regenerated by a process in which the acid is subjected to distillation with sulfuric acid. In one embodiment, the process comprises (a) providing a spent etchant comprising at least about 10% by weight chloride and at least about 5% dissolved copper; (b) adding at least about 2 moles of sulfuric acid per mole of dissolved copper to the spent etching solution, thereby converting copper chloride into hydrochloric acid and precipitated copper sulfate; (c) distilling the mixture from step (b) to vaporize at least a portion of the hydrochloric acid; (d) condensing at least a portion of the vaporized hydrochloric acid; (e) separating at least a portion of the precipitated copper sulfate from the residual liquid, wherein the residual liquid comprises sulfuric acid; and (f) reusing at least a portion of the residual liquid as a sulfuric acid source in step (b).;COPYRIGHT: (C)2007,JPO&INPIT