Recycling chemical waste in the manufacture of printed circuit boards: report of an academic research project (Program of Scientific Initiation Voluntary)

Abstract

This article proposes a method of recovering a ferric chloride solution, which, after constant use for corrosion of printed circuit boards, produces a corrosive solution containing copper. This process of plate corrosion is quite common in the electronics area, being carried out in laboratories and in the domestic environment, as a result, it is improperly disposed of in the sewage system. The engineering student aims at the most effective method, however, which has the least impact on the environment when studying a process. Thus, this study provides a professional growth of engineering undergraduates by recycling the ferric chloride solution, which inappropriate disposal damages the sewage system and causes harm to human health and the environment, and would reduce expenses in the institution, where the solution is used in the laboratories of the Electrical Engineering Department and would be handled by a third party at the end of its useful life. By presenting three recovery methods, the project studies which method is the most efficient and offers the least risk to the operator, since these methods are also carried out in a domestic environment. The tests performed with the solutions recovered from the methods presented allow the comparison and understanding of the importance of each step of the recovery processes, thus, it is possible to propose a new method synthesizing the steps of the other processes that really matter in the recycling of the solution and that allows the recovery of copper in solution for further studies, how to add value to this residue, possibly increasing the useful life of the recycled solution. The new method can be performed in a domestic environment, as it uses easily accessible materials and does not pose great risks to operators. In the laboratory, using materials with a higher level of purity and in high concentrations, it is possible to obtain a more efficient corrosion and absorb the production of spent perchloride solution from the laboratories of the Institution's Electrical Engineering Department.