变径液固两相流分选床回收废弃线路板中金属的研究

Study of Recovery of Metals from Discarded Printed Circuit Boards Using a Liquid-Solid Two-Phase Flow Varied Diameter Fluidized Bed

根据废弃线路板破碎解离物料中金属与非金属颗粒密度特性及运动特性的差异，研制了水介质变径液固两相流分选装置及工艺，对0．5～0．25，0．25～0．125，0．125～0．074，〈0．074mm这4个粒级废弃线路板物料分粒级进行了金属的富集回收分选实验．结果表明：前3个粒级产品的金属品位与回收率同时达到90％以上，〈0．074mm物料的金属品位与回收率分别为65．51％及93．42％，工艺上实现了水介质的循环利用．

An experimental apparatus and process of a liquid-solid two-phase flow varied diameter fluidized bed were developed based on density differences of separated discarded printed circuit boards （PCBs） among which metals and nonmetals are liberated completely. Separated materials were divided into four size fractions of 0. 5 -0. 25, 0. 25 - 0. 125, 0. 125 - 0. 074 and 〈0. 074 mm. Experiment results show that, for 0. 5-0. 25, 0.25-0. 125, 0. 125-0. 074 PCBs, the grade and recovery of metals are higher than 90%, and for 〈0. 074mm PCBs, are 65.51% and 93.42%, respectively. The recirculated water medium was used in the process.