HYDROMETALLURGY PROCESS FOR THE RECOVERY OF MATERIALS FROM ELECTRONIC BOARDS

摘要

A hydrometallurgical process for the recovery of materials from electronic boards and comprising at least one leaching stage (1) and one fractional precipitation stage (4) applied to the solution resulting from the leaching stage. In the leaching stage the whole electronic board is immersed for a time ranging from 15 m to 48 h in a leaching solution comprising HNO3 at a concentration greater than or equal to 20% by weight and with a solid/liquid ratio below or equal to 1. The process also comprises a vibrating sieving stage (2) in which the solution of HNO3 resulting from the leaching stage (1) is passed through at least one first sieve having holes with a size ranging from 10 to 3 mm for the recovery of unwelded components of different nature, and at least one second sieve having holes with a size ranging from 0.5 to 0.01 mm for the recovery of metallic Au; and a separation stage of stannic oxide and/or stannic acid (3) in which the leachedresulting from the vibrating sieving stage (2) undergoes a physical separation operation for the recovery of stannic oxide and/or stannic acid.