Síntese de espinélios a partir do lodo de galvanoplastia

Abstract

With the advancement of civilization, there has been a significant increase in industrial waste, such as Electroplating Sludge (ES), a solid byproduct of galvanization baths. In the current context, the preservation of natural resources, cost reduction, ecological awareness, and the promotion of a self-sustaining economy have been reorienting human actions. At the Manaus Industrial Hub (MIH), the production of hazardous waste, including that from electroplating, has reached 1,529.42 tons annually. This study proposed a methodology to synthesize magnetic spinels from ES at the MIH. The reuse of ES combines the recycling of industrial waste, contributes to the circular economy (CE), and aligns with the United Nations' Sustainable Development Goals (SDGs), particularly SDGs 9 and 12. For this study, a company from the MIH provided ES samples, which were dried at room temperature (RT) and transformed into spinels through a patented process. The advantage of transforming ES lies in reducing the amount of waste discarded by the industry at the MIH. The obtained magnetic materials (MM) have potential for various applications, such as magnetic sensors, catalysts, paints, among others, benefiting fields like electronics, medicine, and automation. Furthermore, the process promotes CE at the MIH, mitigating contamination issues associated with ES. The samples were characterized using techniques such as XRF, XRD (including Rietveld structural-crystallographic refinement), and SEM. XRD results indicated the presence of calcite, quartz, hematite, alumina, and bornite, along with other oxides detected by XRF. The evaluation of soil fertility with the application of SAMM (soil with magnetic material) showed positive results regarding CEC (Cation Exchange Capacity) and other chemical and physical analyses. The cost-benefit study of reusing ES for MM production demonstrated economic and technical viability, with favorable prospects for large-scale production.