Hard Metals (HM) production plays a fundamental role in economy and technological development. Due to the criticality of its main raw materials, W and Co, a sustainable HM waste recycling is hence desirable for both environmental and economic reasons and strongly encouraged by European waste management directives. This work describes a new solvometallurgical leaching method based on diluted maleic acid (H₂Mal) ethanolic solutions, which demonstrated to couple effectiveness in materials enhancement from HM waste, with mildness and sustainability of operative conditions. Specifically, H₂Mal (0.5 M, EtOH) selectively and quantitatively leached Co trapped within WC-Co powders, to afford [Co(HMal)₂(H₂O)₄] complex within 4 h at room temperature and leaving WC unreacted and ready for re-employment in HM manufacturing. Characterization of the resultant materials i.e. treated powders (SEM-EDS, p-XRD, ICP-OES) and Co-leaching solutions (ICP-OES), confirmed the near quantitative Co removal as well as the possibility to finely tune the composition of WC-Co mixtures. Parameters for best leaching conditions, i.e. time and liquid-to-solid ratio, were obtained. A scale-up experiment addressed to test the leaching conditions and the quality of the recycled material is also described. The quality of the recycled material for direct re-employment in HM manufacturing was validated by Metallurgical Quality Control, to good effect. Finally, preliminary experiments on cobalt metal recovery from the metal complex by electrowinning and by quantitative precipitation as CoCO₃ were performed with encouraging results: a step forward resources circularity.

硬质金属（HM）生产在经济和技术发展中起着根本性的作用。由于其主要原料W和Co的关键性，因此出于环境和经济原因，可持续的HM废物回收是可取的，并且受到欧洲废物管理指令的大力鼓励。这项工作描述了一种基于稀马来酸（H ₂ Mal）乙醇溶液的新型溶剂冶金浸出方法，该方法证明了将重金属废料增强材料的有效性与操作条件的温和性和可持续性相结合。具体而言，将H ₂ Mal（0.5 M，EtOH）选择性和定量浸出的Co捕集在WC-Co粉末中，得到[Co（HMal）₂（H ₂ O）₄]在室温下4小时内形成复合物，而WC未反应，可以重新用于HM制造中。对所得材料（即处理后的粉末（SEM-EDS，p-XRD，ICP-OES）和共浸出溶液（ICP-OES））进行表征，证实了近定量的Co去除率以及微调WC组成的可能性-Co混合物。获得了最佳浸出条件的参数，即时间和液固比。还描述了用于测试浸出条件和回收材料质量的放大实验。通过冶金质量控制验证了用于HM制造的直接再利用的再生材料的质量，效果良好。最后，_3项工作取得了令人鼓舞的结果：资源循环性向前迈进了一步。