Scrap Circuit Boards Microwave Integrated Recycling Pilot Study Of New Technologies

Waste circuit board , the basis of electric and electronic industry, is increasing rapidly in recent years , subsequently , huge amounts of waste circuit board is displayed. Waste circuit board recycling has been reinforced by strict legislations and will be pushed ahead by the increasing environmental awareness. Waste circuit board is composed of many common metals , including copper ,aluminum ,lead ,tin and iron , certain amount of noble metals ,including gold ,silver .palladium , and platinum .So it need proper method to reduce the volume of the pollutant, utilize and recycle the useful composition. In this experiment the waste circuit board is crashed and use gravity separation to separate apart the organic matter and the metal. The separated plastic and so on high polymer organic matter is activated carbon by chemical activation method microwave irradiaton, the metal matter uses the manganese dioxide as the oxidant microwave assistance method to leaching copper, aluminum, iron, zinc and so on low-priced metals contained in waste electric circuit board, recycles valuable metal.Study on preparation of activated carbon from waste circuit board plastic by zinc chloride-microwave method. The effect rule of microwave power, radiation time and Zncl₂ solution concentration to the adsorption capability and yield in preparation for activated carbon were studied. The effect rule of factors and processing optimum conditions on preparation for activated carbon were obtained by orthogonal test. The experiment showed that microwave power, radiation time and Zncl₂ solution were contributed to the adsorption capability and the yield, the primary and secondary sequence of the iodine value is microwave power>radiation time>Zncl₂ solution concentration, the primary and secondary sequence of the methylene blue value is microwave power>Zncl2 solution concentration>radiation time, the primary and secondary sequence of the yield is radiation time>microwave power>Zncl₂ solution concentration, The best technology condition on preparation for waste circuit board-based activated carbon with zinc chloride -microwave method was obtained: microwave power was 633W, radiation time was 8min, Zncl₂ solution concentration was 40%.The iodine value of the waste circuit board-based activated carbon was 426.8mg/g,the methylene blue value was 52.4mg/g,and the yield was 37.3%..Study on preparation of activated carbon from waste circuit boardplastic by phosphoric acid-microwave method. The effect rule of microwave power, radiation time and H₃PO₄ solution concentration to the adsorption capability and yield in preparation for activated carbon were studied. The effect rule of factors and processing optimum conditions on preparation for activated carbon were obtained by orthogonal test. The experiment showed that microwave power, radiation time and H₃PO₄ solution concentration were contributed to the adsorption capability and the yield, the primary and secondary sequence of the iodine value is microwave power>H₃PO₄ solution concentration>radiation time, the primary and secondary sequence of the methylene blue value is microwave power>H₃PO₄ solution concentration>radiation time, the primary and secondary sequence of the yield is microwave power>radiation time>H₃PO₄ solution concentration, The best technology condition on preparation for waste circuit board-based activated carbon with phosphoric acid -microwave method was obtained: microwave power was792W, radiation time was 10min, H₃PO₄ solution concentration was 30%.The iodine value of the waste circuit board-based activated carbon was 404.8mg/g, the methylene blue value was 47.2mg/g, and the yield was 38.1%.The add of manganese dioxide was propitious to copper leaching in waste circuit board hydrometallurgy leaching iron, aluminum, zinc, copper and so on low-priced metals test. The effect rule of sulphuric acid concentration, reaction time and reaction temperature to the low-priced metals leaching efficiency were studied in the test. The change of microwave power and heating time effects on the low-priced metals leaching efficiency in microwave heating substitute water bath heating test were also included. The experiment showed that at 1 -3mol/L sulphuric acid low concentration the low-priced metals leaching efficiency increased with sulphuric acid concentration, while sulphuric acid concentration above 3mol/L the low-priced metals leaching efficiency droved. The enhance of reaction time and reaction temperature were both propitious to low-priced metals leaching. Microwave heating did good to iron, aluminum, zinc leaching, but made against copper leaching.In this teat we designed produce oxidize zinc technique to recovery zinc, fluid film-electrodeposition method to recovery copper, produce sulfate aluminum technique to recovery aluminum. As the waste gas adopted lye and activated carbon absorb method, waste water used sulphide deposition method, waste residue solidified, have double benefit of resourcerecovery and environment.Innovate to some extent on the technological process, feasiblely and simple, this technics have double benefit of economy and environment.