Method for recycling silver from waste IC chips using soluble starch

A method, comprising:

• 1) heating to disassemble an IC chip, and crushing the IC chip into powders;
• 2) adding the powders to a nitric acid solution to yield a first mixture, heating and centrifuging the first mixture, and collecting a first filtrate comprising iron (Fe);
• 3) adding soluble starch to the first filtrate obtained in 2) to yield a second mixture, wherein a mass concentration ratio of the soluble starch to Fe in the first filtrate is 5.20-7.30;
• heating the second mixture to 130-175° C. for a first hydrothermal reaction, separating a first precipitate from the first hydrothermal reaction and collecting a second filtrate;
• 4) heating the second filtrate to 160-230° C. for a second hydrothermal reaction, separating a second precipitate from the second hydrothermal reaction and collecting a third filtrate;
• drying, grinding, and sieving the second precipitate to obtain silver powders;
• and
• 5) adding alkali to the third filtrate to form a third precipitate of Cu, and separating the third precipitate to yield cupric hydroxide.