De-coppering of Metallurgical Slag Using Printed Circuit Boards as a Reducer

Abstract

In the publication of the results of laboratory tests for de-coppering metallurgical slag using a variable addition of "LOW GRADE" PCB scrap as a reducer (dates from 10 to 30% of the slag mass). In practical devices, as well as research on de-coppering metallurgical slag using coke - a currently used reducer. The tests involved four measurement series differing in the source of the reducer and the variable process involved. The process was carried out at temperatures of 1350 and 1450°C. Two measurements were taken for each variant analysed. The conducted research showed the possibility of effective use of printed circuit board scrap in the slag de-coppering process. An additional advantage of its use was the introduction of an additional charge of copper into the process at an average level of 10% by mass, which was recovered during the process in the form of a metal alloy. The metal alloy formed during the slag reduction process acted as a collector for the copper contained in the PCB scrap. Research has shown that as the amount of reducer in the form of PCB scrap increases, the final Cu content in the slag after reduction increases. The highest average degree of slag de-copperization was achieved when 10% of PCB scrap was added to the reduction. At the analyzed temperatures it ranged from 95.2 to 97.5%. When coke was used as a reducing agent at a temperature of 1350°C, the average degree of slag de-copperization was from about 60 (2 h) to about 75.5% (4 h). Increasing the process temperature to 1450°C resulted in a significant increase in the slag de-copperization rate, above 97%, regardless of the process duration.