自矽晶切片廢渣中回收矽與碳化矽之研究

Recovery of Si and SiC from spent silicon sawing slurry

譚兆鵬(Choa-Peng Tan)

指導教授 ： 蔡子萱

國立臺北科技大學/工程學院/資源工程研究所/碩士(2013年)

摘要

矽晶在切片成晶圓的過程中會產生龐大的廢料，其中所含的切割液、矽、碳化矽等均有相當高的回收價值。尋求低成本與簡單的矽晶切片廢渣回收方法將有助於製程減廢，同時能大幅降低成本。本研究專注於回收矽晶切片廢渣中的矽與碳化矽，實驗探討多種載劑對矽與碳化矽沉降行為的影響，結果顯示利用X劑作為載劑的沉降速度較快，且廢渣粉體會以分散形式沉降，此種沉降有利於矽和碳化矽的分離。廢渣於X劑中沉降實驗發現，固含量30 wt.%，0.5小時後，上層粉體的矽含量由原廢渣中的30.62 wt.%提升至70.3 wt.%，鐵含量則由7.13 wt.%.下降至0.87 wt.%，矽回收率達68.9 wt.%；下層粉體的矽含量下降至1.12 wt.%，此時鐵含量為0.37 wt.%，碳化矽回收率約53.7 wt.%。改用離心法發現，固含量10 wt.%，300 rpm離心60分鐘後，上層粉體的矽含量提升至88.6 wt.%，但鐵含量高達2.6 wt.%，矽回收率僅10.4 wt.%。併入磁選後，富矽粉體中，矽含量可高達89 wt.%，鐵含量0.85 wt.%，鐵移除率達88.1 %，矽回收率約為20.2 wt.%。本研究以低耗能、簡單、環保的分離技術達成矽和碳化矽的富集，成功地回收矽或碳化矽。

關鍵字

矽 ； 碳化矽 ； 沉降 ； 離心 ； 回收

並列摘要

In Si-ingot slicing process, a great amount of spent silicon sawing slurry is produced. Several materials in the spent silicon sawing slurry are worthy of recovery, such as glycol liquor, silicon, silicon carbide. Developing a low-cost and simple recycling process will help decrease the amount of waste and reduce the manufacturing cost. The purpose of this study is to recover silicon and silicon carbide from spent silicon sawing slurry by sedimentation and centrifugation using various carriers. The experimental results show the settling velocity of waste powders in carrier-X was faster than in other carriers, and its settling belonged to dispersed form, which was helpful of the separation of Si and SiC. When solid content was 30 wt.% for a 30-min settling using carrier-X, Si content of the upper layer increased from 30.62 wt.% to 70.3 wt.%, Fe content decreased from 7.13 wt.% to 0.87 wt.%, and the recovery percentage of Si was 68.9 wt.%. And Si content of the lower layer decreased to 1.12 wt.%, Fe content decreased 0.37 wt.%, and the recovery percentage of SiC was about 53.7 wt.%. In centrifugation experiments with 300 rpm for 1 hour, when solid content was 10 wt.%, Si content of the upper layer increased to 88.6 wt.%, Fe content was 2.6 wt.%, but the recovery percentage of Si was only 10.4 wt.%. With the operation of magnetic separation, the highest Si content reached 89 wt.% and Fe content was only 0.85 wt.%. Fe removal fraction was 88.1 wt.%, and the recovery percentage of Si was 20.2 wt.%. This study separated and concentrated Si and SiC from spent silicon sawing slurry successfully using low energy consuming, simple and environmental friendly method.

並列關鍵字

Silicon ； Silicon carbide ； Sedimentation ； Centrifugation ； Recovery

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