Waste circuit board recovery processing method

A recycling technology for waste circuit boards, applied in the direction of manufacturing tools, metal processing equipment, process efficiency improvement, etc., can solve the problems of loss, high equipment requirements, environmental secondary pollution, etc., and achieve small loss and simple tin removal process , high recovery and high purity

Inactive Publication Date: 2015-05-20
HUNAN VARY TECH
View PDF8 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Taking metal tin on waste circuit boards as an example, at present, in the process of removing tin and removing components, there are mainly two types: physical heating and melting detin and chemical solvent dissolution detin: using chemical solvent to remove tin must use corrosion This method has high requirements on equipment and is easy to cause secondary pollution to the environment; physical heating method is the most common method of tin removal, which can be divided into infrared heating and thermal heating according to different heating methods. Air heating, metal conduction heating and high-frequency induction heating, these methods of direct heating detinning often produce smoke and gas during the tin melting process, and at the same time, the oxidation and loss of solder are relatively serious, resulting in poor recovery and purity of tin. high

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] Mix calcium nitrate, potassium nitrate, sodium nitrate, and sodium nitrite evenly according to the mass ratio of 1.2:5.8:2:1, and add them to the salt tank with circulating mesh belt, heating and temperature control, at the bottom of the salt tank There is a discharge port, and a valve is set on the discharge port, and the molten salt is heated until the molten salt is melted at about 150°C, and continues to be heated to 270°C.

[0022] Remove plastics, batteries, wires, etc. from waste circuit boards; place the solder side of waste circuit boards on the circulating mesh belt, and as the circulating mesh belt moves, the circuit boards are immersed in the liquid surface of molten salt; adjust the circulation The speed of the mesh belt keeps the circuit board in the molten salt for 2 minutes, and at the same time vibrates the waste circuit board (such as knocking on the upper surface of the waste circuit board) to make the molten solder fall off more easily and enter the m...

Embodiment 2

[0027] Mix calcium nitrate, potassium nitrate, sodium nitrate and sodium nitrite uniformly according to the mass ratio of 1:6.9:2.1:1, add them to the salt tank with circulating mesh belt, heating and temperature control, turn on the heater to melt The salt is heated, and the molten salt melts at about 140°C, and continues to be heated to 290°C.

[0028] Remove plastics, batteries, wires, etc. from waste circuit boards; place the solder side of waste circuit boards on the circulating mesh belt, and as the circulating mesh belt moves, the circuit boards are immersed in the liquid surface of molten salt; adjust the circulation The speed of the mesh belt keeps the circuit board in the molten salt for 1.5 minutes, and knocks on the waste circuit board to make the molten solder fall off and enter the molten salt more easily; when the waste circuit board is removed from the salt tank, flip the substrate and vibrate to make the components fall off, or scrape off the components with a...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
melting pointaaaaaaaaaa
decomposition temperatureaaaaaaaaaa
Login to view more

Abstract

The invention discloses a waste circuit board recovery processing method. The waste circuit board recovery processing method comprises the steps that 1, the plastic, the battery and the electric wire on a waste circuit board are removed; 2, a soldering side of the waste circuit board is immersed into the molten salt liquid downward until the tin is molten; 3, component on a base board of the waste circuit board is removed, and the base board and the component are cleaned with water; 4, the molten tin is recycled from the molten salt, and the molten tin is cooled until being solidified. The waste circuit board recovery processing method has the advantages that the molten salt is used for melting the soldering tin on the waste circuit board, the molten tin is cooled and solidified, and the soldering tin ingot is recycled; both the base board and the component are washed with water, the environmentally-friendly and efficient detinning process is achieved, and secondary pollution additive is not introduced into the detinning process; the tin oxidation degree and the loss are low, and the recovery and purity of the tin are high.

Description

technical field [0001] The invention relates to the field of waste recycling, in particular to a method for recycling waste circuit boards. Background technique [0002] The printed circuit board (PCB) industry is the foundation of the electronic and electrical industry, and its output and consumption are huge. In 2012, the global printed circuit board output value reached 54.31 billion US dollars (National Statistical Yearbook 2013). my country is the world's largest producer and consumer of printed circuit boards, accounting for about 40% of the world (2013 annual report of the global electronic circuit industry), and more than 500,000 tons of waste printed circuit boards (WPCB) are discarded in my country every year (China Plastics Industry 2013 Statistical Report). The incineration of a large number of waste circuit boards will produce toxic gases. The discarded circuit boards and simple landfills will also pollute the surrounding land and water resources with heavy meta...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): B23K1/018C22B25/06
CPCB23K1/018C22B25/06Y02P10/20Y02P70/10
Inventor 明果英张长安左志越
Owner HUNAN VARY TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap