title: Characterization and mechanical separation of metals from computer Printed Circuit Boards (PCBs) based on mineral processing methods.
abstract: In this paper, a novel mechanical process is proposed for enriching metal content of computer Printed Circuit Boards (PCBs). The PCBs are crushed and divided into three different size fractions namely: -0.59, +0.59 to 1.68 and +1.68 mm. Wet jigging and froth flotation methods are selected for metal enrichment. The coarse size fraction (+1.68 mm) is processed by jigging. The plastic free product is grinded and screened. The oversized product is separated as the first concentrate. It was rich of metal because the grinding process was selective. The undersized product is processed by froth flotation. Based on the obtained results, the middle size fraction (+0.59 to 1.68 mm) and the small size fraction (-0.59 mm) are processed by wet jigging and froth flotation respectively. The wet jigging process is optimized by investigating the effect of pulsation frequency and water flow rate. The results of examining the effect of particle size, solid to liquid ratio, conditioning time and using apolar collector showed that collectorless flotation is a promising method for separating nonmetals of PCBs. 95.6%, 97.5% and 85% of metal content of coarse size, middle size and small size fraction are recovered. The grades of obtained concentrates were 63.3%, 92.5% and 75% respectively. The total recovery is calculated as 95.64% and the grade of the final concentrate was 71.26%. Determining the grade of copper and gold in the final product reveals that 4.95% of copper and 24.46% of gold are lost during the concentration. The major part of the lost gold is accumulated in froth flotation tail.
authors.affiliation: Department of Mining and Metallurgical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran.
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Sarvar
authors.affiliation: Department of Mining and Metallurgical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran.
authors.forename: Mohammad Mehdi
authors.initials: MM
authors.lastname: Salarirad
authors.affiliation: Department of Mining and Metallurgical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran.
authors.forename: Mohammad Amin
authors.initials: MA
authors.lastname: Shabani
mesh_terms: D003201:Computers; D059029:Electronic Waste / Q000032:analysis*; D008670:Metals / Q000032:analysis*; D018505:Waste Management / Q000379:methods*
chemical_list: D008670:Metals
keywords: Characterization; Density separation; Froth flotation; Mechanical separation; Printed Circuit Board; Wet jigging