从酸性氯化铜蚀刻废液中回收氧化亚铜和氯化钠

Reclamation of cuprous oxide and sodium chloride from spent acidic copper chloride etching solution

以某PCB(印制线路板)厂的酸性CuCl_2蚀刻废液为原料,采用液相法制备Cu_2O,并对其中的NaCl进行回收。研究了水合肼与废液中Cu^(2+)的浓度比、pH、反应温度、时间等参数对Cu_2O纯度的影响,得到最佳工艺条件为:先在水合肼与Cu^(2+)的浓度比为0.2625、pH=4~5和室温之下沉淀和还原,再在pH=12、100 ℃之下取代和脱水反应1 h。所得Cu_2O的纯度达98.4%,铜杂质含量小于0.07%,满足HG/T 2961–2010中优等品的要求。回收的NaCl纯度高于97.5%,符合GB/T 5462–2015中二级精制工业盐的要求。

Cu2O was prepared by liquid phase method using a spent acid CuCl2 etching solution from a PCB （printed circuit board） factory as raw material, and NaCl was reclaimed. The effect of process parameters including the concentration ratio of hydrazine hydrate to Cu^2＋ in the spent etching solution, pH, as well as reaction temperature and time on the purity of Cu2O were studied. The optimal process conditions are as follows： precipitation and reduction at hydrazine hydrate-to-Cu^2＋ concentration ratio of 0.2625, pH 4-5 and room temperature followed by substitution and dehydration at pH 12 and temperature 100℃ for 1 h. The purity of the obtained Cu2O under the optimal conditions reaches 98.4% with the content of copper impurity less than 0.07%, meeting the requirement of high-class product stipulated by HG/T 2961-2010 standard. The purity of the reclaimed NaCl is above 97.5%, meeting the GB/T 5462-2015 standard for secondary refined industrial salt.