| Development of economy and the coming electronic information age lead to continuous metaboilsm of various Electric and Electronic Equipment(EEE).These products make out of much Waste EEE (WEEE). WEEE destroy environment and endanger people's health. But on the other side, they have great value:they were made of many kinds of metal and nonmetal substance. Printed circuit board scrap(PCBs) is recognized as a typical kind of electronics waste, and a challenge to effective disposal. Treatment and recycling of this kind of wastes properly have been laid store by researchers all over the world. Whereas, any attempt on basal research has not been made in our country up to the present.Firstly, the existing and potential technologies used for the treatment and recycling of PCBs have been identified and assessed in this thesis. Afterwards, printed circuit boards scrap material composition and characteristics of pyrolysis are studied by a variety of methods. This study has been processed as the following aspects:(1) First of all, the oxidizing roast experiment of PCB scrap is carried out at 380℃in air atmosphere, then the composition of roasting products under 200 mesh is analyzed with atomic absorption spectrometry, predicating apparatus, spectrophoto-meter etc equipment ;with it, the physical-chemistry characteristics of the main compositions of PCBs have been determined qualitatively and quantificationally in this thesis.(2) The tg-dta analysis results of Printed circuit boards scrap material indicate that, except auto line and red side material, the other three scrap material belongs to the categories of printed circuit boards; After, the pyrolysis experiment is carried on the hot furnace, the differences of between pyrolysis experiment and thermal analysis experiment are compared. Application of reaction kinetics theory analysis and verified, the pyrolysis reaction of the printed circuit boards scrap is divided into three main stages, based on the sample of pyrolysis dynamics research, the experimental samples of three dynamics factors and the pyrolysis dynamics model were established, each sample pyrolysis dynamics equations are determined. (3) Thermal analysis is carried on the printed circuit boards scrap of excluding metal components. The sample's TG and DTG curve with different atmosphere are compared, and we research on the thermal characteristic parameters of different atmosphere. It provide valuable basis for the industrial recovery of waste PCB, and we can determine the best atmosphere of pyrolysis reaction.Finally, the main research contents of this thesis are summarized and we provided guidance for industrial recovery. The problems existing in the current research and the even further research contents are pointed out, and we define research content of next step. |
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