含銅蝕刻廢液回收奈米氧化銅之最佳化技術研究

Optimal Technology for Recovery of Cupric Oxide Nanopowders from Copper-containing Etchant Wastes

蔡宗晏(Zong-Yan Tsai)

指導教授 ： 林錕松

元智大學/工程學院/化學工程與材料科學學系/碩士(2012年)

https://doi.org/10.6838/YZU.2012.00155

摘要

印刷電路板廠每年排放約6,000萬公升的含10-15%銅蝕刻廢液，目前於業界中大都使用分流或儲存委外處理方式；因此本研究主要目的為使用在印刷電路板業中含銅量較高之酸性含氯化銅蝕刻液，硫酸雙氧水蝕刻液及鹼性蝕刻液；在藉由酸鹼中和法將酸性蝕刻液及鹼性蝕刻液製備成為奈米氧化銅粉末並追求其純度最佳化之條件，以達廢棄物資源再利用之永續經營。
本實驗使用氫氧化鈉中和法可分為水浴法與超音波震盪法兩種，其中中和法又分為正滴定及逆滴定方式進行，並控制不同pH值、水洗次數、反應溫度及煅燒溫度，以找出最佳化回收奈米氧化銅粉末的方法，在中和反應蝕刻液添加氫氧化鈉溶液時，當溫度低於40℃且pH = 5-8時形成氧氯化銅CuCl2．3Cu(OH)2，而pH = 9則形成Cu(OH)2；不過在高於50℃且pH＞10時，則轉變成為CuO。液體殘留物及CuO沉澱物的性質將會藉由數種儀器分析。藉由場發掃描式電子顯微鏡(FE-SEM)觀察不同反應溫度之產物，溫度低於40℃以下按照滴定方式的不同形成不同的結構，正滴定形成片狀團聚而逆滴定則是顆粒團聚狀結構其大小約40 nm 至60 nm，若溫度高於40℃不論正逆滴定都形成片狀與顆粒共存結構，而在50℃時其顆粒大小約80 nm 至 100 nm，使用超音波震盪法可以得到片狀與長條狀共存的結構，比較此三種合成奈米氧化銅方法，在酸鹼中和反應時因反應溫度的不同由顆粒狀形成膠狀，而導致在較低溫時不易攪拌；而當反應溫度高於50℃時即形成氧化銅粉末且易於攪拌；使用超音波震盪法，可增快合成反應速率，所生成之氧化銅粉末具反應時間短的優點。
使用熱重法(TGA)分析以不同滴定方式、反應溫度及煅燒溫度下所合成之奈米氧化銅粉末，其中逆滴定、反應溫度60℃、煅燒溫度600℃條件下之奈米氧化銅粉末雜質含量最少純度最高。另外，利用X-ray粉末繞射儀(XRD)比較不同反應溫度及煅燒溫度之晶形結構，由圖譜得知經過450℃以上溫度煅燒過後，原本含部分CuCl2也已經因加熱還原部分Cl2並氧化形成氧化銅粉末。為了深入瞭解奈米氧化銅產物之表面精細結構，進一步使用光電子能譜儀(XPS)對奈米氧化銅粉末進行分析，在Cu 2p3能階顯示為Cu(II)及平面四方型結構，由此推斷本實驗所製備出之奈米氧化銅粉末主要為CuO而非Cu2O的結構。由ICP/AES分析奈米氧化銅粉末之銅離子濃度，金屬銅含量達99%以上，且生成之副產物主要有水、氯化鈉及微量Zn等重金屬，符合PCB廠氧化銅回收再利用為原料之基本品質規範。

關鍵字

印刷電路板 ； 奈米氧化銅 ； 氯化銅蝕刻液 ； 鹼性蝕刻液 ； 硫酸雙氧水蝕刻液 ； 氫氧化鈉中和法 ； 水熱法 ； 超音波震盪法 ； 資源回收再利用。

並列摘要

At present, over 60 million liters 10-15% copper-containing waste etchants (CCWEs) generated from printed circuit board (PCB) manufacturing per year are disposed by partial discharge and storage way in Taiwan. Therefore this research focuses on the preparation of cupric oxide nanopowders from high concentration of copper-containing CCWEs by acid-base neutralization reaction between acid and base CCWEs in order to pursuit optimize conditions of purity achieving the sustainable reuse of waste resources.
In this experiment, the methods of alkali hydroxide neutralization can divided into hydrothermal and ultrasonic method, and the neutralization method can also divided into titration and inverse titration. The control factor of the experiments includes pH values, reaction temperatures and calcination temperatures to find the optimal way of CuO nanopowders recovery from CCWEs. During the addition of NaOH solution into CCWEs in neutralization reaction, the precipitates of CuCl2．3Cu(OH)2 and Cu(OH)2 were formed below 40℃ at pH = 5-8 and 9, respectively. However, the CuO nanopowders were produced above 50℃ and pH＞10. The properties of liquid residues and CuO precipitates were further analyzed by using several instruments. From the FE-SEM microphotos of products produced by different reaction temperatures, temperature is below 40℃ following the formation of different structures. Titration method will cause the formation of flake aggregation, otherwise inverse titration is agglomerated particle structure about the size of 40 nm to 60 nm. But when the temperature above 40℃ neither titration nor inverse titration, the CuO forms flake and particle coexist structure whose particle size distribute between 40 to 60 nm. At 50℃, the particle size distribute about 80 nm to 100 nm. By comparing the results of these three CuO synthesis methods, acid-base neutralization will transform the structure change from particle to collision because of different reaction times. And when reaction temperature over 50℃, it forms CuO powder and easy to stir. Ultrasonic methods is able to accelerate reaction rate, and the produced CuO powder will had the advantage of shorte-reaction time.
From TGA curves of CuO nanopowder synthesized by different titration methods, reaction and calcination temperatures, it can be seen that CuO nanopowder synthesized by inverse titration method under 60℃ reaction temperature and 600℃ calcination temperature had the highest purity and less impurities. On the other hand, XRD patterns showed after calcination at 450℃, the precipitates transformed from CuCl2．3Cu(OH)2 to CuO at pH = 10-12. Existence of the Cu(II) and the planar tetragonal structure were confirmed by XPS spectra. From ICP/AES data, it is observed that more than 99% of copper in CuO recovered from CCWEs. The major residues in treated CCWEs after recovery of CuO nanopowders were NaCl, H2O and trace heavy metals such as Zn, Pb, Ni, Mn or Cr species.

並列關鍵字

Printed circuit board ； Cupric oxide nanopowders ； Copper chloride etching solution ； Alkaline etching solution ； Sulfuric acid hydrogen peroxide etching solution ； Sodium hydroxide neutralization ； Hydrothermal method ； Ultrasonic method ； Resource recovery and reuse.

參考文獻

95.燿華電子股份有限公司，「含銅廢水（液）產生高含銅污泥之處理方法」，中華民國專利，(2007)。

7.林忠舜，「利用酸鹼中和法由氯化銅酸性蝕刻廢液製備奈米氧化銅微粒之研究」，碩士論文，元智大學化學工程與材料科學研究所 （2004）。

16.Zeblisky R.J., Peroxy containing compositions, U.S. Patent, 3809588 (1974).

17.Margulies P.H. and Kressbach J.E., Process and composition for the dissolution of copper, U.S. Patent, 2978301 (1961).

19.Glanville J.O., Stabilization of acidified hydrogen peroxide solutions, U.S. Patent, 3649194 (1972).