In this study, microwave pyrolysis, two-stage acid leaching, precipitation and chemical etching methods were carried out for resource recovery from spent c-Si solar modules. Compared with conventional pyrolysis, microwave pyrolysis should be a better pretreatment process, because it can provide higher aluminum recovery rate and would not alter the surface structure and composition of c-Si solar modules as conventional pyrolysis did. The recovery products, including aluminum, silver and silicon crystal, were obtained with the recovery rates of 94.90 %, 95.74 % and 83 %, and the purities of 99.63 %, 100 % and 99.98 %, respectively. Cylindrical diffusion and pseudo-second-order models best fit the experimental data of sulfuric acid and nitric acid leaching, respectively, implying that the mechanisms of aluminum and silver dissolution would be different. The return on investment of spent c-Si solar modules recycling by using the methods involved in this study would be approximately 113 %. Therefore, total resource recovery from spent c-Si solar modules can be nearly achieved by using these methods, showing great potential for commercial applications and high possibility of establishing circular economy. The operational parameters and reaction kinetics found in this study can be applied to other kinds of solar modules or electronic waste for resource recovery and environmental protection.

中文翻译：

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利用微波热解、酸浸和化学蚀刻从废旧晶体硅太阳能组件中回收资源


在这项研究中，进行了微波热解、两阶段酸浸、沉淀和化学蚀刻方法，用于从废旧 c-Si 太阳能组件中回收资源。与传统热解相比，微波热解应该是一种更好的前处理工艺，因为它可以提供更高的铝回收率，并且不会像传统热解那样改变 c-Si 太阳能组件的表面结构和成分。得到的回收产物包括铝、银和硅晶体，回收率分别为 94.90 %、95.74 % 和 83 %，纯度分别为 99.63 %、100 % 和 99.98 %。圆柱形扩散模型和准二级模型分别最符合硫酸和硝酸浸出的实验数据，这意味着铝和银的溶解机制会有所不同。使用本研究涉及的方法回收废旧 c-Si 太阳能组件的投资回报率约为 113%。因此，使用这些方法几乎可以实现废旧 c-Si 太阳能组件的总资源回收，显示出巨大的商业应用潜力和建立循环经济的巨大可能性。本研究中的操作参数和反应动力学可以应用于其他种类的太阳能组件或电子垃圾，以实现资源回收和环境保护。