Method for recycling worn semiconductor

Abstract

The invention discloses a method for recycling a worn semiconductor. The method comprises the following steps: crushing the worn semiconductor, and guiding the crushed semiconductor into a first reaction container; adding a catalyst to the first reaction container and heating the crushed semiconductor to 80-100 DEG C, and initiating a reaction until waste acid is decomposed; filtering precipitatesin the first reaction container, and introducing waste water into a second reaction container; and adding a magnesium source catalyst into the second reaction container based on the pH value in the waste water, adding acid or alkali to adjust the pH value of waste liquid to maintain between 8.0 to 10.0, and stirring to promote the reaction until supernatant and crystalline precipitates are separated for the second time. Compared with the prior art, the method has the following advantages that by recycling phosphorus in the waste water, the shortage crisis of phosphorus supply in industrial and agricultural production is effectively relieved; and the method is an effective way to realize circular economy and ecological economy and has remarkable environmental, economic and social benefits.

Description

technical field [0001] The invention relates to the technical field of semiconductor recycling technology, in particular to a method for recycling old semiconductors. Background technique [0002] As the size of semiconductor devices becomes smaller and more integrated, trace impurities in semiconductor devices have a greater impact on semiconductor devices. Therefore, the SPM waste acid produced by the semiconductor cleaning process contains 60%-85% of sulfuric acid 0.5 %-5% hydrogen peroxide, the residue of hydrogen peroxide is unfavorable for safe transportation, storage, recycling and reuse in other production processes; at present, the industry adopts the direct addition of metal ion catalysts in waste acid, citing metal impurities, and cannot removal, resulting in the inability to recycle for commercial reuse. For example, to recover and recommercialize the sulfuric acid in waste acid, the concentration of hydrogen peroxide must be controlled below 2ppm, and no other i...

AI Technical Summary

Problems solved by technology

[0002] As the size of semiconductor devices becomes smaller and more integrated, trace impurities in semiconductor devices have a greater impact on semiconductor devices. Therefore, the SPM waste acid produced by the semiconductor cleaning process contains 60%-85% of sulfuric acid 0.5 %-5% hydrogen peroxide, the residue of hydrogen peroxide is unfavorable for safe transportation, storage, recycling and reuse in other production processes; at present, the industry adopts the direct addition of metal ion catalysts in waste acid, citing metal impurities, and cannot removal, resulting in the inability to recycle for commercial reuse. For example, to recover and recommercialize the sulfuric acid in waste acid, the concentration of hydrogen peroxide must be controlled below 2ppm, and no other impurities are brought in; conventional metal catalysts catalyze decomposition Hydrogen peroxide is easy to introduce impurities, and it takes a very long time to reduce it to below 2ppm, and the cost control is not ideal. It also takes a lot of time to directly use conventional photocatalytic decomposition of hydrogen peroxide, and it is difficult to achieve the semiconductor cleaning process. Requirements for impurity control; semiconductor industry production wastewater has the characteristics of large discharge, various types of pollutants, and complex components. It is difficult to deal with industrial wastewater; the removal and recovery of high-concentration phosphorus in semiconductor production wastewater has always been a technical bottleneck, and a large amount of phosphorus-containing wastewater is discharged into surface water bodies, which will cause serious eutrophication problems; at the same time, phosphorus is a vital activity It is an indispensable and important element in the human body, and it is an important natural resource and industrial and agricultural raw material that is non-renewable and facing depletion. Therefore, phosphorus removal and phosphorus recovery from wastewater have received extensive attention as an important research topic.