Waste printed circuit board (PCB) is the most important part of Waste electronic and electric equipment (WEEE), and also one of the most arduous job to deal with because of its heterogeneity and high complexity. Crushing is the crucial process for the technology of recycling waste PCB, for chemical and bio-metallurgy methods, the process of crushing could have enough chance to make the surface of particles contacting with medicaments, again for physical methods, the process of crushing could directly cause the efficiency of successive separation, the recovery rate and purity of metal. In order to study the rupture mechanism of waste printed circuit boards (PCB), an S-3000N scanning electron microscope (SEM) and electron spectroscopy (EDS) were adopted to analyzed boundary of PCB particles. The surface topography of PCB particles manifests self- similarity, which shows particle possesses fractal characteristics. Based on the fractal theory and computer images analysis technique, a MATLAB program which computes box fractal dimension of material fracture was designed. The linear degree of fit beeline of MATLAB program is high, which shows fractal behavior of the boundary of PCB particle is obvious. The different fractal dimension of 6 particles shows that complexity and roughness of fracture were different. The order of complexity and roughness of particle boundary from high to low is: d>c>a>f>e>b, and these accords with the visual observing, which further shows that the crushed PCB particle boundary possesses fractal characteristics.
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机译:废纸印刷电路板(PCB)是废物电子和电气设备(WEEE)最重要的部分,而且由于其异质性和高复杂性而处理的最艰巨的工作之一。压碎是回收废弃物PCB技术的关键过程,用于化学和生物冶金方法,破碎过程可以有足够的机会使粒子表面与药物接触,再次用于物理方法,破碎过程可以直接粉碎过程导致连续分离的效率,金属的恢复率和纯度。为了研究废印刷电路板(PCB)的破裂机制,采用S-3000N扫描电子显微镜(SEM)和电子光谱(EDS)分析了PCB颗粒的边界。 PCB颗粒的表面形貌表现出自相似性,显示颗粒具有分形特征。基于分形理论和计算机图像分析技术,设计了一种计算材料骨折盒分形尺寸的MATLAB程序。 MATLAB程序的拟合直线的线性度为高,显示PCB粒子的边界的分形行为是显而易见的。 6颗粒的不同分形尺寸表明骨折的复杂性和粗糙度不同。从高到低的粒子边界的复杂性和粗糙度的顺序是:D> C> A> F> E> B,并且这些符合视觉观察,进一步表明被压碎的PCB粒子边界具有分形特征。
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