109年度補助應回收廢棄物回收處理創新及研究發展計畫-開發廢印刷電路板銅回收精煉與氮氧化物減量回收技術
| 中文摘要 | 本研究與優勝奈米有限公司進行合作，將廢印刷電路板中的銅進行回收與精煉，採用破碎分離、硝酸溶銅以及還原置換等方式進行銅回收，然而在過程中會產生硝酸銅廢液以及高濃度氮氧化物排放，導致二次污染問題，因此，本研究利用超重力旋轉床進行硝酸溶銅製程中產生之氮氧化物減量去除效益評估，廢液部分則以減壓蒸餾法進行廢液減量。超重力旋轉填充床相較於傳統填充塔，可降低氣液之間的質傳限制，提升質傳效率，增加對氮氧化物的吸收效果。本研究目標建立廢電路板破碎分離與硝酸銅回收製程、評估硝酸銅溶液還原回收效果、以減壓蒸餾法回收還原後廢液、以及超重力技術對氮氧化物去除之功能評估。 研究結果發現，廢印刷電路板破碎分離篩分後結果進行分析，粒徑分布大於150um佔總重量之87.8%，且電路板碎片具有572 g/Kg的銅含量，銅含量由原本的491 g/Kg，提升了16%的銅含量。還原法銅回收結果顯示，當鐵粉投入量提升到1 : 2時，還原後的硝酸水溶液銅濃度為0.375 g/L，銅還原率提升到99.75%。此外，將硝酸銅還原後廢液，進行減壓蒸餾。經過減壓蒸餾後，可減少廢液率達70%；針對氮氧化物去除部分，每批次進樣2.5克之銅片與40毫升之硝酸(濃度約9M)，最高氮氧化物濃度為2212 ppm，其中一氧化氮與二氧化氮比值約為0.8，以雙氧水、二氧化氯溶液與臭氧作為氧化劑，以臭氧對於氮氧化物去除效率可高達86%。 | ||
|---|---|---|---|
| 中文關鍵字 | 銅回收精煉、超重力旋轉填充床、氮氧化物減量 | ||
基本資訊
| 專案計畫編號 | EPA-109- XB05 | 經費年度 | 109 | 計畫經費 | 1122.222 千元 |
|---|---|---|---|---|---|
| 專案開始日期 | 2020/02/01 | 專案結束日期 | 2020/11/30 | 專案主持人 | 蔣本基 |
| 主辦單位 | 回收基管會 | 承辦人 | 吳柏宏 | 執行單位 | 國立臺灣大學環境工程學研究所 |
成果下載
| 類型 | 檔名 | 檔案大小 | 說明 |
|---|---|---|---|
| 期末報告 | 附件1-2.期末報告(定稿).pdf | 5MB | 期末報告(定稿本) |
Development of waste circuit board copper recycling, refining and nitrogen oxides reduction technologies
| 英文摘要 | In this study, we cooperated with UWin Nanotech Co., Ltd. to recycle and refine the copper from the waste printed circuit board (PCB). The series processes including crushing, separation, dissolution, and reduction were used to recover the copper. However, the waste liquid will be generated in the process as well as the high concentration of nitrogen oxide (NOx) emissions. Therefore, we used a high-gravity rotating packed bed (HiGee RPB) to reduce the NOx emissions from the copper dissolution process. The waste liquid was treated by vacuum distillation before discharge. Compared with the traditional packed tower, the HiGee RPB can eliminate the mass transfer limitation between gas and liquid, thereby improving the mass transfer efficiency the absorption effect of NOx. The objectives of this study are to establish an integrated process for copper recovery from the waste PCB, to evaluate the effect of reduction and recovery of copper nitrate solution, to recover the waste liquid after reduction by vacuum distillation, and to evaluate the NOx removal via a HiGee RPB. The results indicated that the sieve analysis after the crushing and separation of the waste PCB with the particle size distribution greater than 150um accounted for 87.8% of the total weight. The board fragments had a copper content of 572 g/kg that compared to original copper content of 491 g/Kg. It was increased by 16%. The copper recovery results from the reduction method showed that when the iron powder input was increased to 1:2, the copper concentration of the reduced nitric acid aqueous solution was 0.375 g/L, and the copper reduction rate was increased to 99.75%. In addition, the waste liquid after reduction of copper nitrate was treated by vacuum distillation. After vacuum distillation, the amount of waste liquid can be reduced by 70%. For the removal of NOx, each batch of 2.5 g of copper chips and 40 mL of nitric acid (concentration of about 9M) was conducted, resulting in the maximum NOx concentration is 2200 ppm. The ratio of NO and NO2 is about 0.8. We used hydrogen peroxide, chlorine dioxide solution and ozone as oxidants, which the NOx removal efficiency of 86% by ozone can be achieved. | ||
|---|---|---|---|
| 英文關鍵字 | Copper recycle and refining, High-gravity rotating packed bed, Nitrogen oxide reduction | ||