Feasibility Study of Waste Motor Recycling through Manual Dismantling and Hydrometallurgical Process

Abstract

Huge amount of waste electrical and electronic equipments (WEEE) or electronic waste (E-waste) has been produced every year in the world. It consists of valuable and hazardous metals that can be reused or extracted to minimize the environmental impact. This study is focusing on the investigation of recycling potential of e-waste through manual dismantling process and leaching test. The leaching test was conducted by changing the initial pH with constant stirring speed, constant water-sample ratio and in open air. The morphological structures of the solid samples were observed by SEM and the liquid residue was analyzed by Atomic Absorption Spectroscopy (AAS). It was found that total time required to dismantle all parts in the waste motor is about 10 minutes and the part that required longest dismantling time was armature windings. The metal elements that were observed are Fe, Mg, Pb and Cr. It was found that the pH of the solution increased with the increasing leaching time. The dissolution of Fe and Pb was high in the early stage of leaching but gradually decreased afterward. The dissolution for Mg and Cr was low throughout the leaching process. It was revealed that the metal elements in e-waste can be dissolved using this method and further investigation to increase the dissolution rate is required to ensure that the method proposed is applicable in industry. However, dissolved concentration of Pb must be controlled to ensure that it follows the permissible amount set under environmental standard.

Review on Current Status of Waste Electric and Electronic Product in Malaysia

“…Even though there are many method in dissolving, as an engineer we should find the best methods by considering the parameters such as temperature, particle size, pouring density and so on. First step in recycling process is manual dismantling, which enable the recovery of whole homogenous parts that may will be valuable, recyclable or reusable, such as whole components, plastic, glass or metal parts, and hazardous component that require further special treatment, such as batteries, waste motor, mercury containing components, LCD and CRT-glass [19,20]. Further liberation and size reduction of the recyclable materials, such as PCBs, is usually achieved by some kind of crushing process or shredding [21].…”