Crushing is the key part for the recycling technology of waste printed circuit boards (WPCBs). In this study, the breakage and liberation effects of WPCBs was improved by heat pretreatment technology before crushing (HPBC). Based on the test results, 200 °C was found as the safe temperature for the HPBC of WPCBs. The fracture mode, particle size distribution, and enrichment characteristics of WPCBs were systematically studied. The experimental results show that the HPBC changed the breakage mode from longitudinal fracture to horizontal fracture and improved the liberation of metal from non-metal components. During the crushing process, the increase in the heat pretreatment time (30–120 min) and temperature (100–200 °C) can improve the crushing effect of WPCBs and increase the content of crushing products of −0.3 mm by 3.16% and 5.64%, respectively. Compared to the non-metallic components, the metal components have ductility and are difficult to break into −0.3 mm during the crushing process. HPBC can promote copper enrichment to narrow grain size. In the 0.3–1 mm range, the content of copper increased from 47.87% to 57.61%, an increase by 9.74%. The initial enrichment of copper was achieved by adjusting the crushing time. The recovery rate of copper can reach 85.66%, and the enrichment rate is 1.74 when 0.3–2 mm breaking product is used as enrichment. Therefore, HPBC can effectively improve the crushing and liberation effect of WPCBs and improve the enrichment rate, and thus is an effective pretreatment method.

粉碎是废印刷电路板（WPCB）回收技术的关键部分。在这项研究中，通过压碎前的热处理技术（HPBC）改善了WPCB的断裂和释放效果。根据测试结果，发现WPCB的HPBC的安全温度为200°C。系统地研究了WPCB的断裂模式，粒度分布和富集特性。实验结果表明，HPBC将断裂模式从纵向断裂转变为水平断裂，并改善了金属从非金属成分中的释放。在压碎过程中，热处理时间（30–120分钟）和温度（100–200°C）的增加可以提高WPCB的压碎效果，并将-0.3 mm压碎产物的含量提高3.16％和5.64。 ％， 分别。与非金属部件相比，金属部件具有延展性，并且在破碎过程中难以断裂成-0.3 mm。HPBC可促进铜富集以缩小晶粒尺寸。在0.3-1 mm范围内，铜含量从47.87％增加到57.61％，增加了9.74％。铜的初始富集通过调整破碎时间来实现。铜的回收率可以达到85.66％，当使用0.3–2 mm破碎产品进行富集时，富集率为1.74。因此，HPBC可以有效提高WPCB的粉碎和释放效果，提高富集率，是一种有效的预处理方法。HPBC可促进铜富集以缩小晶粒尺寸。在0.3-1 mm范围内，铜含量从47.87％增加到57.61％，增加了9.74％。铜的初始富集通过调整破碎时间来实现。铜的回收率可以达到85.66％，当使用0.3–2 mm破碎产品进行富集时，富集率为1.74。因此，HPBC可以有效提高WPCB的粉碎和释放效果，提高富集率，是一种有效的预处理方法。HPBC可促进铜富集以缩小晶粒尺寸。在0.3-1 mm范围内，铜含量从47.87％增加到57.61％，增加了9.74％。铜的初始富集通过调整破碎时间来实现。铜的回收率可达到85.66％，当使用0.3–2 mm破碎产品进行富集时，富集率为1.74。因此，HPBC可以有效提高WPCB的粉碎和释放效果，提高富集率，是一种有效的预处理方法。