| 摘要 |
PURPOSE: To simultaneously recover copper sulfate(CuSO4) and calcium chloride(CaCl2) from waste copper chloride solution used as an etchant of printed circuit board(PCB) in high purity. CONSTITUTION: This method comprises the steps of (i) agitating waste copper chloride solution in a reactor as neutralizing with calcium carbonate or calcium hydroxide in the temperature range of 70 to 95deg.C, resulting in the formation of both calcium chloride and copper carbonate/copper hydroxide, wherein the chemical reaction is as follows:{(CuCl2+HCl)+CaCO3→CaCl2+CO3↓} or {(CuCl2+HCl)+Ca(OH)2→ CaCl2+Cu(OH)2↓} ; (ii) separating water-soluble calcium chloride from copper carbonate/copper hydroxide that are insoluble to water, by dissolving calcium chloride in water; (iii) recovering solid calcium chloride by evaporating water; (iv) after rinsing copper carbonate/copper hydroxide precipitates with water, slowly adding sulfuric acid to rinsed copper carbonate/copper hydroxide precipitates, resulting in the formation of copper sulfate and carbon dioxide; (v) rinsing obtained copper sulfate with methanol comprising at least 75% of alcohol in order to eliminate chlorides that would exist in recovered copper sulfate. |
