Method for removing heavy metals from electronic waste outer shell PS plastic

Abstract

The invention discloses a method for removing heavy metals from an electronic waste outer shell PS plastic. The method mainly comprises three steps of pretreatment, soaking and heating, wherein a hydrogen peroxide-containing mixed acid solution (formed by mixing concentrated nitric acid and tetrafluoroboric acid) is heated to dissolve the plastic additive attached to the waste plastic so as to remove heavy metals from the PS plastic, such that the separation of heavy metals Pb, Cd, Cr and Sb from the plastic is achieved, and the heavy metal content in the waste plastic is reduced. With the method of the present invention, the heavy metals in the PS plastic can be effectively removed, the maximum removal efficiency can reach 95%, the removal efficiency is high, and the cost is low.

Description

technical field [0001] The invention relates to the technical field of waste recycling, in particular to a method for removing heavy metals from PS plastics in electronic waste shells. Background technique [0002] The development trend of thinner, lighter and smaller electronic products has led to a large amount of plastics being used to replace traditional components. Foreign surveys and statistics on the weight ratio of materials for 21 types of scrapped electronic and electrical equipment, among which plastics account for 2.8%-43.7%, iron accounts for 45.9%-51.7%, aluminum accounts for 1.3%-9.3%, and circuit boards account for 0.5%- 9.4%. According to statistics, in 2016, the global e-waste output reached 4.47×10 7 t, the per capita amounted to 6.1kg, an increase of 5% compared with the per capita amount in 2014, and it is expected that the total amount will reach 5.22×10 in 2021 7 t. In order to meet the needs of different users, it is necessary to add a certain amo...

AI Technical Summary

Problems solved by technology

On the one hand, waste plastics as garbage landfills occupy a large area of ​​land and waste land resources, and because plastics themselves contain toxic and harmful substances such as heavy metals and flame retardants, long-term landfills in the soil will enter the soil and water sources with the garbage leachate. Causes environmental pollution, so plastic recycling has become the main trend in dealing with waste plastics

However, due to the high concentration of heavy metal additives in early plastics, the content of harmful substances in recycled waste plastics is still high, and there are still hazards to the human body and the surrounding environment during use. Effective removal of heavy metals in waste plastics can reduce Hazards of waste plastic recycling products

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