鑄造業鋅合金之表面處理及廢液處理之研究

A Study of the Electroplating Zinc Alloy Casting and Its Waste Liquid Treatment

陳憶蘋(I-Pin Chen)

指導教授 ： 李志賢

崑山科技大學/工程學院/環境工程研究所/碩士(2011年)

摘要

本文探討鑄造業與表面處理業兩個相關產業的現況與生產流程，並以一不規則形狀鋅合金鑄件的鍍銅、鎳、金及鍍層品質檢驗，包括外觀、厚度、成份分析，以及電鍍鎳、銅廢液的電解回收，設計系列實驗。電解回收會受到電極表面電雙層、電解質離子濃度與離子電荷、離子擴散速率等因素的影響。鋅合金鑄件表面常存留孔隙，微裂縫、氧化物等，且鋅為兩性元素，易受酸與鹼腐蝕，在大氣環境下，容易生成氧化鋅，因此，鋅合金鑄件的前處理與電鍍銅鎳的表面處理，對鋅鑄件的防蝕與保固是重要的技術，電鍍金可提升耐蝕性與外表的美觀。
在電鍍銅過程，必須先進行銅打底，若使用氰化亞銅，有氰離子影響生態環境，此外，銅離子與鎳離子有重金屬污染的顧慮，金鹽屬於高價位化學原料，所以本文除了使用鹼性氧化法破壞氰離子與銅離子的錯化合物，使銅離子成為自由離子狀態，容易電解回收減廢，也考慮電解過程，電雙層厚度會影響電解效率，利用惰性粒子撞擊電極表面，避免電雙層在電極表面生成，或是降低電雙層厚度，有助於金屬陽離子的擴散及電解還原，研究結果顯示使用惰性玻璃微粒沖擊電極表面，使吸附電極表面的氣體加速脫離，減少氣體極化與電雙層厚度，降低離子擴散阻礙，可有效提升廢液中的鎳電解回收效率31%，銅電解回收效率57%，金屬膜表面狀態亦較為細緻。

關鍵字

鋅合金 ； 電鍍銅鎳 ； 電鍍廢液

並列摘要

This study discussed present situations and production process of the casting industry and surface treatment industry. Zinc base alloy casting with anomalous shapes for copper, nickel and gold-plating, and coating quality restriction were studied by outward appearance, thickness, and ingredient analysis. The electro-nickel and copper waste liquid electrolysis recycling was designed a series of experiment. The electrolysis recycling can be affected with the electrode surface electricity double-decked, electrolyte concentration, ionic charge, and diffusion of ions speed influences. The zinc base alloy casting surface was often found the holes, micro crack, and oxide compound in the atmospheric environment. Otherwise, the process of zinc base alloy casting and the surface treatment of the electro-copper and nickel is important technologies which can decrease the damage of the zinc alloy casting. In addition, this process will increase the corrosion resistance and semblance artistic of the zinc alloy casting.
In the electro-coppering process, the cuprous cyanide might product the cyanogen, copper, and nickel ions that pollute the environment. This study used the alkalinity oxidized-process to destruct the cyanogen ion and the cupric ion complex compound. This method causes the cupric ion to become the free ion condition and the electrolysis recycling easy to reduce wastes. The electricity double layer often affects the electrolysis efficiency. It will avoid the electricity double layer in the electrode surface production, perhaps will reduce the electricity double layer thickness. That will be helpful in the metal positive ion proliferation and the electrolytic reduction. The electrode surface, causing the adsorption electrode surface the gas to accelerate to be separated from, reduces the gas polarization and electricity double layer thickness, and also reduces the diffusion of ions hindrance, but promotes in the waste liquid effectively the nickel electrolysis recovery efficiency with 31%, the copper electrolysis recovery efficiency with 57%, and the metallic membrane surface condition is also more careful.

並列關鍵字

Zinc base alloy casting ； electro-nickel and electric-copper ； waste liquid

參考文獻

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