A simple eco-friendly process is proposed to retrieve tin from waste printed circuit boards (WPCBs) as tin oxide nanostructured powders. The WPCBs were leached in disodium salt of ethylene diamine tetraacetic acid (Na₂-EDTA) chelating agent comparing results with acid leaching. Parameters affecting the leaching process such as sample particle size, pH, temperature, time, liquid/solid ratio, and concentration of Na₂-EDTA were investigated. A 100% of Sn can be recovered by leaching in 0.1 mol/L Na₂-EDTA solution for 3 hours at 80 °C with optimum conditions of pH: 5, liquid/solid ratio: 30, particle size −0.07 mm, and constant stirring of 400 rpm. Kinetic data suggest a diffusion-controlled process as the rate-determining step for the Na₂-EDTA extraction of tin from WPCBs with an activation energy of 15.28 KJ·mol⁻¹. Selective precipitation of Sn as tin oxide (SnO₂) nanoparticles (NPs) from leachant solution was performed via a simple route using sodium hydroxide. Characterization tests (XRD, FTIR, EDX, FE-SEM, and TEM) were made to confirm the morphology of the nanoparticles. The prepared SnO₂ NPs, having a size range of 8–12 nm, showed an excellent photocatalytic action towards methylene blue (MB) dye under ultraviolet (UV) light illumination with 90% efficiency after 180 min and showed good reusability after five consecutive cycles.

提出了一种简单的环保工艺来从废印刷电路板 (WPCB) 中回收锡作为氧化锡纳米结构粉末。将 WPCB 在乙二胺四乙酸 (Na ₂ -EDTA) 螯合剂的二钠盐中浸出，与酸浸出的结果进行比较。研究了影响浸出过程的参数，例如样品粒度、pH、温度、时间、液/固比和Na ₂ -EDTA的浓度。通过在 0.1 mol/L Na ₂ -EDTA 溶液中在 80 °C 下浸出3 小时，最佳条件为 pH 值：5、液固比：30、粒径 -0.07 mm 和恒定，可以回收 100% 的锡400转/分的搅拌。动力学数据表明扩散控制过程作为 Na ₂的速率决定步骤-EDTA 从 WPCB 中提取锡，活化能为 15.28 KJ·mol ^-1。通过使用氢氧化钠的简单途径，从浸出液中选择性沉淀锡作为氧化锡 (SnO ₂ ) 纳米颗粒 (NPs)。进行表征测试（XRD、FTIR、EDX、FE-SEM 和 TEM）以确认纳米颗粒的形态。制备的 SnO ₂ NPs 的尺寸范围为 8-12 nm，在紫外 (UV) 光照射下对亚甲蓝 (MB) 染料显示出优异的光催化作用，180 分钟后效率为 90%，并在连续五个循环后显示出良好的可重复使用性.