Environmentally Friendly Technology of Recovering Nickel Resources and Producing Nano-Al2O3 from Waste Metal Film Resistors

E-waste is mass-producing in the current world. Recovery technologies of e-waste are developing from crude to environmentally friendly and high-efficiency. Along with waste printed circuit boards, abundant waste resistors were generated. However, there is little information about their recovery technology. Waste metallic film resistors contain a 33.2 wt % ceramics matrix and 65.1 wt % nickel. If it is not properly treated, nickel will be exposed to and harm the environment and humans. This paper presents environmentally friendly and value-added recovery technology of waste metallic film resistors. The recovery technology includes shearing, magnetic separation, and milling. The shearing process was used to liberate the materials contained in waste metallic film resistors. The materials were completely liberated when sheared to 2-25 mm particle sizes. Magnetic separation was efficient for separating nickel particle from sheared materials, and the separation rate reached 100 wt %. The ceramic material was identified as Al2O3, and it were milled into nano-Al2O3. The particle size of nano-Al2O3 ranged from 100 to 500 nm, and it was an important powder coating material. The economic benefit of recovering waste metallic film resistors was analyzed based on energy costs, equipment depreciation cost, labor cost, and economic income. This paper reminds practitioners of e-waste recovery to pay close attention to recovering waste metallic film resistors and avoid environmental pollution.