关键词: 蚀刻废液, 碱式氯化铜, 多晶型, 工业结晶, 热化学

Abstract:

Copper oxychloride produced from the reaction of acid and alkaline etching waste solution of printed circuit board are normal the mixture of multiple crystal forms,which affects the purity and performance of product.In order to produce copper oxychloride with single crystal form,the reaction conditions of feeding rate,temperature,pH were optimized in the continue crystallization process,and the products with single crystal form of Atacamite（type-A）,Botallackite（type-B） and Clinoatacamite（type-C） and with the respective purity of 99.0%,99.7% and 90.7% were obtained.The XRD and SEM results showed that type-A crystal belonged to orthorhombic and was the long strip and flake aggregates;type-B crystal belonged to monoclinic and was the hexagonal single crystal aggregates;type-C crystal also belonged to monoclinic but was the irregular flaky aggregates.Chemical analysis and TG-DSC showed that the molecular formula of A,B and C products was Cu₄（OH）₆Cl₂·H₂O,Cu₅（OH）₈Cl₂ and CuCl₂·3Cu（OH）₂·0.5H₂O,respectively.The activation energy and heat of decomposition of A,B and C products were different.Among the three products,B-type copper oxychloride had the highest copper content and the strongest thermal stability,which was the best crystal product in copper oxychloride production.

Key words: etching waste solution, copper oxychloride, polycrystalline, industrial crystallization, thermochemistry