Comprehensive recovery method of pyrolysis polymetallic product from waste integrated circuit board

Patent metadata

Field	Value
Publication number	US-11447846-B2
Application number	US-201917609277-A
Country	US
Kind code	B2
Filing date	Jul 17, 2019
Priority date	May 7, 2019
Publication date	Sep 20, 2022
Grant date	Sep 20, 2022

Abstract

The invention relates to a method for multi-metal products recovery from pyrolytic waste integrated circuit boards. The method mainly comprises the steps of smelting and blending, atomization, acidolysis and filtration, noble metal recycling, copper extraction and back extraction, nickel extraction and back extraction. Compared with the prior art, the method has the advantages that smoke pollution and the smelting slag treatment in the process of preparing a black copper ingot through multi-metal collaborative smelting are reduced, and the problems of low anode efficiency of the black copper electrolysis process are solved. Meanwhile, the high-temperature high-oxygen atomized gas generated in the atomizing process provides a heat source and an oxygen source for subsequent acidolysis, so that the energy consumption is further reduced. The method has the advantages such as short process, remarkable energy conservation and emission reduction.

First claim

The invention claimed is:

1. A method for multi-metal products recovery from pyrolytic waste integrated circuit boards, comprising the following steps:
(1) melting and blending: adding multi-metals obtained by pyrolysis of waste integrated circuit boards into a smelting furnace, and adding a covering agent for smelting and blending under 1200-1350° C. for 0.5-1 hour to obtain an alloy solution, wherein the covering agent comprises one of carbon powder or coal powder, and an amount of covering agent added is 5-15% of the mass of multi-metals;
(2) atomization: atomize the alloy solution obtained in step (1) to obtain atomized powder and atomized gas;
(3) acidolysis and filtration: the atomized powder obtained in step (2) is immersed in an acidolysis solution for acidolysis reaction, the acidolysis solution and acidolysis slag are obtained by filtration, and the acidolysis slag is recovered to obtain rare and precious metals;
(4) copper extraction and back extraction: the acidolysis solution obtained in step (3) is subjected to copper extraction and back extraction to obtain copper sulfate and copper raffinate;
(5) nickel extraction and back extraction: copper raffinate obtained in step (4) is subjected to nickel extraction and back extraction to obtain nickel sulfate and nickel raffinate, and the nickel raffinate returns to the acidolysis and filtration step as a supplementary solution of the acidolysis solution,
wherein during the atomization step, an atomization water pressure is 10-15 MPa, an oxygen pressure is 1-1.2 MPa, and a nozzle aperture is 2˜3 mm,
wherein during the acidolysis and filtration step, 150-200 kg/m 3 sulfuric acid is used as the acidolysis solution, the solution-solid ratio is 10 L:1 kg-15 L:1 kg, the atomization gas obtained in step (2) is stirred with a flow rate of 1-300 L/min per liter of the acidolysis solution, the acidolysis reaction uses 98 mass percent industrial concentrated sulfuric acid for acidity adjustment, a time of the acidolysis is 1-3 hours, and a pH at the end of the acidolysis reaction is 3-4.

Assignees

• Univ Beijing Technology

Inventors

• Pan Dean
• Wu Yufeng
• Li Bin

Classifications

• C22B23/043 Primary

  Sulfurated acids or salts thereof · CPC title

• C22B23/02

  by dry processes · CPC title

• C22B15/0071

  containing sulfur · CPC title

• C22B15/0028

  Smelting or converting · CPC title

• C22B11/046

  from manufactured products, e.g. from printed circuit boards, from photographic films, paper or baths · CPC title