Machining operations of cast parts usually generate considerable amounts of waste in the form of chips (usually 3–5% of the casting weight). Traditionally, swarf is sold to scrapers and remelters, but this option is quite expensive because the selling price is roughly 30% of the acquisition price of the commercial 2nd melt raw material. For most aluminium foundries that incorporate machining operations in their products, reusing aluminium chips as raw material for the melting stocks is perhaps the best option as waste management policy in what concerns to economical and technical aspects. Nevertheless, aluminium swarf is a low density product (0.25 kg/dm3) and is usually covered by a thin film of aluminium oxide and machining fluid. Melting such a product without suitable previous preparation leads to very low metal recovery rates, high energy consumption, gases and smoke generation and very low quality of the final product.During the last years, the authors have developed a high efficient and environmentally friend aluminium swarf recycling technique, using direct incorporation in aluminium melts. The influence of processing parameters, namely melt temperature and holding time, melting atmosphere, swarf briquetting pressure and melting charge composition in the metal recovery yield and dross generation was studied and characterized, and the optimal processing parameters were established. The microstructure of the final product obtained in those conditions was evaluated and is also presented.It is shown that the recycling efficiency depends on the swarf conditioning, the melting technique and the melt treatment methodology. Swarf moisture reduction, induction melting under protective atmosphere and a specially developed degassing technique were found the most important factors influencing the recycling process. By using the developed technique, cast ingots with microstructure and sanity similar to commercially available AlSi12Cu1 2nd melt raw material were successfully obtained with minimal dross formation and metal recovery rates around 90%, without using traditional salts and fluxes
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机译：铸件的机加工操作通常会产生大量切屑形式的废料（通常为铸件重量的3–5％）。传统上，将切屑出售给刮板机和重熔机，但是这种选择相当昂贵，因为其售价大约是商用第二种熔融原料的收购价的30％。对于大多数在其产品中进行机械加工的铝铸造厂，考虑到经济和技术方面的问题，将铝屑作为原料用作熔化原料可能是废物管理政策的最佳选择。然而，铝屑是一种低密度产品（0.25 kg / dm3），通常被氧化铝和加工液的薄膜覆盖。在没有适当的事先准备的情况下熔化此类产品会导致极低的金属回收率，高能耗，气体和烟雾的产生以及最终产品的质量非常低。在过去的几年中，作者们开发了一种高效且环保的铝屑回收利用技术，该技术通过直接掺入铝熔体中来实现。研究和表征了工艺参数，如熔体温度和保持时间，熔体气氛，切屑压块压力和熔体组成对金属回收率和渣生成的影响，并确定了最佳工艺参数。评估并介绍了在这些条件下获得的最终产品的微观结构。结果表明，回收效率取决于切屑调节，熔化技术和熔化处理方法。发现减少切屑的水分，在保护性气氛下感应熔化以及专门开发的脱气技术是影响回收过程的最重要因素。通过使用开发的技术，无需使用传统的盐和助熔剂，就可以成功获得具有类似于市售AlSi12Cu1第二熔体原料的微观结构和健全度的铸锭，且产生的浮渣最少，金属回收率约为90％。
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