ALL-COMPONENT RAPID MICROWAVE DIGESTION AND NOBLE METAL ION LIQUID EXTRACTION METHOD FOR WASTE CIRCUIT BOARD

摘要

An all-component rapid microwave digestion and noble metal ion liquid extraction method for a waste circuit board, belonging to the field of hydrometallurgy. As microwave can penetrate a leaching medium and directly heat a circuit board, microwave-assisted leaching can enhance mass transfer and heat transfer in a traditional leaching process, greatly reduce leaching time, and increase leaching efficiency. Before leaching, there is no need to crush a waste circuit board, saving energy and protecting the environment. A temperature rise process and a reaction time can be controlled in a reaction, and the whole process is conducted under a sealed condition, avoiding the loss of heat during a leaching process, providing a high leaching rate and high selectivity of valuable metal, achieving the efficient leaching of valuable metal. A noble metal leaching solution is extracted using an imidazole ionic liquid which has high selectivity for gold, avoiding co-extraction with ions such as nickel and copper. The extraction of a noble metal leaching solution by means of an ionic liquid is a clean and green recovery method, and the overall recovery rate of gold, nickel, and copper can reach more than 99%.