電弧爐煙塵複合薄膜對電磁波屏蔽效益之研究

Production Electromagnetic Interference Shielding Composites film using EAF Dust

賴炴璇(Yang-Hsuan Lai)

指導教授 ： 鄭大偉

國立臺北科技大學/工程學院/資源工程研究所/碩士(2010年)

https://doi.org/10.6841/NTUT.2010.00482

摘要

煉製不鏽鋼所產生大量之電弧爐煙塵，為行政院環保署認定之有害事業廢棄物，其每年產量高達250,000噸，對環境有深遠之影響，必須提出有效處理方式以降低對環境的傷害。由電弧爐煙塵之分析中發現主要是尖晶石相礦物，結構與磁鐵礦( Magnetite )或鋅鐵氧磁體( Zinc Ferrite )相近，其成份以鐵和鋅含量最多，非常適合作為電磁波屏蔽/吸收材料。電弧爐煙塵具比重大、顆粒細與毒性溶出之特性，以致使用上受限，而高分子基材具有加工容易、質輕、美觀、低成本與易設計等優點。若以高分子與電弧爐煙塵混摻，將可使電弧爐煙塵包裹於高分子中，降低其毒性溶出，並有效利用電弧爐煙塵中富含鋅鐵氧磁體的特性，製成具電磁波屏蔽/吸收特性的複合薄膜以達集塵灰資源化的目的。
本研究以電弧爐煙塵與高分子混摻使其具電磁波之屏蔽與吸收效益，並選用聚乙烯醇( Polyvinyl Alcohol, PVA )及水性聚氨基甲酸脂( Waterborne Polyurethane, WPUR )兩種高分子進行討論。探討電弧爐煙塵之填充量與複合薄膜之厚度對電磁波屏蔽/吸收效益之影響，並以能量守恆與電場理論對電磁波之反射、穿透及吸收行為進行討論。
實驗成果顯示，未經處理之電弧爐煙塵具有較佳之吸收效益，EAFD/PVA複合薄膜其煙塵填充量為10 vol%，頻率為2484 MHz時，具有-10.13 dB最佳電磁波吸收效益。隨著厚度之增加，其電磁波吸收效益亦提升，推測為反射損失所造成，當反射損失未有明顯之特徵峰時，將使其頻寬增加。當填充量為10 vol%，厚度為1.0 mm時，手機頻段900 MHz可達-4.93 dB最佳電磁波吸收效益。若以WPUR做為高分子，當EAFD/WPUR複合薄膜填充量為15%時，於2450 MHz吸收效益可達-7.88 dB。本研究可提供電弧爐煙塵另一項資源化應用的方向。

關鍵字

電弧爐煙塵 ； 機械冶金法 ； 電磁波屏蔽 ； 鐵氧磁體 ； 聚乙烯醇 ； 聚氨基甲酸脂 ； 電磁波吸收效益

並列摘要

It is estimated that the electric arc furnace dust (EAFD) are produced over 250,000 tons annually in Taiwan. The EAFD is a hazardous industrial waste defined by Environmental Protection Administration (EPA), if it does not treat properly, it will leave a long-term damage to the environment. Therefore, recycling electric arc furnace (EAF) dust becomes an important issue for protecting our living environment. XRD results show that EAFD has a normal spinel structure, which is similar to Magnetite and Zinc Ferrite. Zinc Ferrite (ZnFe2O4) has been widely used in various fields of electromagnetic interference shielding materials, and which is abundant in EAFD. This study is trying to use polymer blended method to make EAFD based composite for electromagnetic shielding/absorption application.
In this study, EAFD/PVA composite films were produced by blend Polyvinyl Alcohol (PVA) with EAFD, and EAFD/WPUR composite films were produced by blend Waterborne Polyurethane (WPUR) with EAFD. The EAFD loading and the thickness of composite films will affect the electromagnetic shielding/absorption effectiveness. The phenomena of electromagnetic waves, such as reflection, transmission and absorption, can be demonstrated by the theory of power conservation and electric field.
Experimental results show that untreated EAFD powder based composite films had higher absorption effectiveness. While PVA films with 10 vol% EAFD loading at 2848 MHz, the electromagnetic absorption effectiveness was about -10.13 dB. The effectiveness increased with increasing film thickness. As films thickness up to 1.0 mm, it presents -4.93 dB at 900 MHz, which is the frequency used for cell phone communication. Blending WPUR with 15 vol% of EAFD could produce EAFD/WPUR composite films, and it can reach -7.88 dB at 2450 MHz. As a consequence of the study, we can provide an alternative approach to recycle EAFD to reduce the environment hazardous.

並列關鍵字

Electric Furance Dust ； Mechanical Alloying ； Electromagnetic Shielding ； Ferrimagnetism ； Polyvinyl Alcohol ； Waterborne Polyurethane ； Electromagnetic Interference Absorbing Effectiveness

參考文獻

[3] 行政院環境保護署，廢棄物資源化技術暨附加價值提昇研究計畫，行政院環境保護署，2006。

[6] Benjamin, J. S., “Dispersion Strengthened Super alloys by Mechanical Alloying”, Metall. Trans., Vol. 1, pp. 2943-2951.

[7] C. Suryanarayana, “Mechanical Alloying and Milling”, Prog. Mater. Sci., Vol. 46, 2001, pp. 1.

[8] 黃廷耀，鋁基塊狀非晶合金之粉末冶金製程研究，碩士論文，大同大學材料工程研究所，2009。

[9] M. Perret, H. Mehrer and N.A. Stolwijk, “Synthesis of Amorphous Co-Nb Alloy Powders by Mechanical Alloying”, Detect and Diffusion Forum, Vol. 66-69, 1989, pp. 1343 ~ 1348.