本文主要研究内容
作者王一鹏（2019）在《废弃线路板中金属的强化重力分选研究》一文中研究指出：With the development of the times and the advent of the electronic network era,the world produces a large amount of electronic waste every day,and China has become one of the largest e-waste producers in the world.Among them,the waste circuit boards applied to various electrical appliances and equipment such as televisions,mobile phones,and computers have become e-wastes with high pollution and high recycling value,and are resources of misplaced places.The waste circuit board contains a large amount of metal,of which copper has the largest specific gravity.How to effectively recycle the metal in the waste circuit board and recycle it is a significant issue.At present,the research on efficiently enriching and recovering metals in waste circuit boards is not very mature.The paper takes the abandoned computer motherboard as the research object,studies its physical and chemical properties and fracture characteristics;studies the effects of heat treatment of the circuit board on its own characteristics and fracture characteristics.The waste product of the waste circuit board was sorted by a Falcon centrifugal sorting machine,and the metal recovery rate was used to evaluate the sorting effect.Compare the sorting effect of the heat treated circuit board and the untreated circuit board under the same conditions.The waste circuit board contains metal elements such as Cu,Fe,Ca,Sn,and Al,and the distribution of these elements has a certain regularity.Cu and Sn,which are present in elemental form,are mainly distributed in the coarse-grained grade,and others exist as compounds.The metal elements are more evenly distributed in each particle size.This is the result of selective fracture in the crushing process,and the selective fracture of the heat-treated circuit board is more obvious.The difference between metal and non-metal density is obvious.The density of metal and its continuous body is mainly concentrated in the density level of+2.2g/cm~3,and the yield reaches 56.37%.It is beneficial to the sorting and enrichment of metals in the enhanced gravity field.The degree of dissociation of the heat-treated circuit board in the 1.0-0.5mm grade metal reaches 98%.At this time,the dissociation degree of the untreated circuit board metal is less than 60%.The heat treatment has the effect of improving the dissociation degree of the metal in the circuit board great help.Under the same conditions,the heat-treated circuit board will break when the stress is 142N,and the untreated circuit board will break when it is 215N.It is proved from the side that the circuit board after heat treatment is more easily broken.Single factor test and document test for Falcon sorting of discarded circuit boards,the sorting rules under various factors were obtained.The single factor test results show that the rotational frequency has the most obvious effect on the recovery rate of metal in the waste circuit board.The orthogonal test results show that there is an interaction between the rotational frequency,recoil pressure and feed rate factors.With the help of the software,the metal recovery rate is the highest in the experimental data,and the best sorting conditions are obtained: the rotation frequency is 25 Hz,the backwash water pressure is 0.02 MPa,and the feed rate is 34 ml/s.With Falcon sorting,the metal recovery rate of the heat treated circuit board is higher under the same conditions.The recovery rate of heat treated circuit board metal was 8.37%higher than that of untreated circuit boards.The paper has 31 pictures,18 tables,and 90 references.
Abstract
With the development of the times and the advent of the electronic network era,the world produces a large amount of electronic waste every day,and China has become one of the largest e-waste producers in the world.Among them,the waste circuit boards applied to various electrical appliances and equipment such as televisions,mobile phones,and computers have become e-wastes with high pollution and high recycling value,and are resources of misplaced places.The waste circuit board contains a large amount of metal,of which copper has the largest specific gravity.How to effectively recycle the metal in the waste circuit board and recycle it is a significant issue.At present,the research on efficiently enriching and recovering metals in waste circuit boards is not very mature.The paper takes the abandoned computer motherboard as the research object,studies its physical and chemical properties and fracture characteristics;studies the effects of heat treatment of the circuit board on its own characteristics and fracture characteristics.The waste product of the waste circuit board was sorted by a Falcon centrifugal sorting machine,and the metal recovery rate was used to evaluate the sorting effect.Compare the sorting effect of the heat treated circuit board and the untreated circuit board under the same conditions.The waste circuit board contains metal elements such as Cu,Fe,Ca,Sn,and Al,and the distribution of these elements has a certain regularity.Cu and Sn,which are present in elemental form,are mainly distributed in the coarse-grained grade,and others exist as compounds.The metal elements are more evenly distributed in each particle size.This is the result of selective fracture in the crushing process,and the selective fracture of the heat-treated circuit board is more obvious.The difference between metal and non-metal density is obvious.The density of metal and its continuous body is mainly concentrated in the density level of+2.2g/cm~3,and the yield reaches 56.37%.It is beneficial to the sorting and enrichment of metals in the enhanced gravity field.The degree of dissociation of the heat-treated circuit board in the 1.0-0.5mm grade metal reaches 98%.At this time,the dissociation degree of the untreated circuit board metal is less than 60%.The heat treatment has the effect of improving the dissociation degree of the metal in the circuit board great help.Under the same conditions,the heat-treated circuit board will break when the stress is 142N,and the untreated circuit board will break when it is 215N.It is proved from the side that the circuit board after heat treatment is more easily broken.Single factor test and document test for Falcon sorting of discarded circuit boards,the sorting rules under various factors were obtained.The single factor test results show that the rotational frequency has the most obvious effect on the recovery rate of metal in the waste circuit board.The orthogonal test results show that there is an interaction between the rotational frequency,recoil pressure and feed rate factors.With the help of the software,the metal recovery rate is the highest in the experimental data,and the best sorting conditions are obtained: the rotation frequency is 25 Hz,the backwash water pressure is 0.02 MPa,and the feed rate is 34 ml/s.With Falcon sorting,the metal recovery rate of the heat treated circuit board is higher under the same conditions.The recovery rate of heat treated circuit board metal was 8.37%higher than that of untreated circuit boards.The paper has 31 pictures,18 tables,and 90 references.
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论文作者分别是来自中国矿业大学的王一鹏，发表于刊物中国矿业大学2019-07-18论文，是一篇关于,中国矿业大学2019-07-18论文的文章。本文可供学术参考使用，各位学者可以免费参考阅读下载，文章观点不代表本站观点，资料来自中国矿业大学2019-07-18论文网站，若本站收录的文献无意侵犯了您的著作版权，请联系我们删除。