Many researchers have examined the welding of machining chips in an extrusion process. Their aim has been to recycle the material into a usable extruded component without melting. Industry has yet to embrace this processing technique despite over a decade of research. We instead investigate the potential to use extrusion as a pre-melting step to increase metal recovery during chip recycling. We extrude aluminum (AA6060) and zinc (Kirksite A) chips under different extrusion ratios. The oxide content of the extruded aluminum is predicted using evidence from the literature and measured using an Auger Nanoprobe. We compare the subsequent metal recovery rates during vmelting to those obtained during: (1) bulk metal recycling; (2) melting of chips by submersion in molten metal; (3) melting of chips with salt fluxes; and (4) melting of previously compacted chip briquettes.

For aluminum chips, it is found that an extrusion ratio of 9 (and higher) results in a fully dense material which, when melted, results in a metal recovery equal to that of bulk metal melting and exceeding that possible by melting chip briquettes. In contrast, extrusion of zinc chips results in a poorly welded, porous rod. Melting of these rods results in a paste of zinc metal entrapped within a zinc oxide honeycomb. Negligible liquid zinc gathers at the base of the crucible and overall metal recovery is lower than during simple melting of un-compacted zinc chips.

Cradle-to-gate life cycle assessments are used to compare conventional recycling of aluminum chips to the new extrusion plus melting route. The latter could result in savings of up to 60 MJ_primary and 6 kgCO_2eq per kilogram of chips recycled.

许多研究人员检查了挤压过程中加工芯片的焊接。他们的目标是将材料回收成可用的挤压组件，而不会熔化。尽管进行了十多年的研究，工业界仍未接受这种加工技术。相反，我们研究了将挤压用作预熔融步骤以提高切屑回收期间金属回收率的潜力。我们以不同的挤压比挤压铝（AA6060）和锌（Kirksite A）切屑。挤压铝的氧化物含量是根据文献证据预测的，并使用俄歇（Auger）纳米探针进行测量。我们将熔炼过程中的后续金属回收率与以下过程中获得的回收率进行了比较：（1）散装金属回收；（2）通过浸入熔融金属中而使木片熔化；（3）用盐熔剂融化木片；

对于铝屑，发现挤出比为9（或更高）会导致完全致密的材料，该材料在熔化时会导致金属回收率与大块金属熔化的熔化率相同，并且超过通过熔化木屑团块而可能达到的回收率。相反，锌屑的挤出导致焊接不良，多孔棒。这些棒的熔化导致锌金属糊剂被困在氧化锌蜂窝体内。可以忽略的液态锌聚集在坩埚的底部，与未压缩的锌片的简单熔化相比，总的金属回收率较低。

从摇篮到大门的生命周期评估用于比较传统的铝屑回收与新的挤压加熔化路线。后者可以节省多达60 MJ的_{初级原料，}每千克回收切屑可节省6 kgCO 2_当量。