以乾式製程技術於大氣環境下製備氧化鋅粉末之研究

Preperations of Zinc Oxide Powerder Using Dry Processing Technology under Atmospheric Conditions

許本松(Pen-Sung Hsu)

指導教授 ： 黃培興

國立屏東科技大學/工學院/機械工程系所/碩士(2013年)

https://doi.org/10.6346/NPUST.2013.00237

摘要

本研究是利用乾式製程技術於大氣環境下製備氧化鋅粉末，使氧化鋅粉末於生產過程中，可降低原料中的鎘、鉛含量，並減少團聚現象及與空氣中的雜質混合等製程改善，獲得粒徑縮小、純度提升的高品質氧化鋅粉體。
實驗過程乃藉由銑件熔爐及反射爐相互配合及熔煉作業參數調整等作法，達到鋅金屬的純化效果並增加量產之目標，將純度提升至99.7 %以上，有效降低「鋅液體」之鎘含量至10 ppm(0.001 wt%)以下及鉛含量降低至50 ppm(0.005 wt%)以下，另於負壓管路進行自然補氣冷卻部分，需與現有生產氧化鋅設備之負壓馬達、管徑與管路長度等相互匹配，至而進行參數優化，使氧化鋅粉末粒徑縮小至230 nm以下目標並降低氧化區之落粉量之生產效益。
因高溫氧化法為一種大氣製程，氧化過程容易與空氣中的雜質混合，造成製程污染導致粉體純度下降，所以建置一半封閉氧化爐隔離之空間，降低鋅蒸氣與空氣中的雜質混合，提升氧化鋅粉體的純度。而氧化鋅粉體於形成階段具有熱團聚之現象，因此於氧化爐出口與負壓抽管接合處，選擇使用氣體熱對流的方式進行有效的冷卻，並設計不同型態的開孔方式取得最佳化設計，使氧化爐出口溫度可迅速降低，來減少後續氧化鋅微粒團聚成長的機會，其冷卻系統考量後續維修製作成本，所以採用熱對流的方式進行負壓管路的有效冷卻，此方式可讓剛成形的氧化鋅粉體粒徑均勻，並使比表面積達4.1 cm2/g以上。

關鍵字

乾式製程 ； 氧化鋅粉末 ； 廢鋅

並列摘要

The study aims to use the dried process technology to produce the ZnO powder in the atmosphere. During the process of ZnO powder production, this technology could not only reduce the cadmium(Cd) and lead(Pb) but also decrease the aggregation from the materials as well as improve the process, such as the mixing impurity in the air. As a result, high-quality ZnO powder was produced with the narrow particle size and higher purity.
The goal of this experiment was to purify Zinc metal and to increase mass production with the methods of shiny metal fumace, reverberating fumace and parameter adjusting of smelting process. The purity was raised to 99.7 % and the content of Cd and Pb was decreased efficiently lower than 10 ppm(0.001 wt%) and 50 ppm(0.005 wt%) in the Zinc liquid. In addition, the nature air filling in the negative pressure piping system was designed to match with negative pressure motor, caliber, and the length of the piping. Furthermore, it optimized the parameter to shrink the ZnO powder particle size less than 230 nm and to produce efficiency of the powder deposition quantity in oxidization region.
Since the high-temperature oxidation process is a method of atmospheric processes, it occurred to be mixed with atmospheric impurity easily, resulting in production pollution and decreased powder purity. Therefore, a closed and isolated space was built in the half area of the oxidation furnace, in order to reduce the impurities of mixing zinc vapor with air, and to enhance the oxidation of zinc powder purity. However, since the zinc oxide powder has the agglomeration effect in the formative stage, the thermal convection was used at the joint of the exports and vacuum pumping tube in the oxidation furnace. Moreover, the different types of openings were applied to achieve an optimal design, so that the oxidation furnace outlet temperature was quickly decreased and the agglomeration effect was reduced. So as to reduce the cost of production and maintenance in the cooling system, the thermal convection was used to perform cooling of the vacuum pipe effectively. With this method, a uniform particle size of newly formed zinc oxide powder was produced, and the specific surface area was above 4.1 cm2/g.

並列關鍵字

dry process ； zinc oxide powder ； waste zinc

參考文獻

[19] 張庭碩, “利用FLUENT進行高容量乾式貯存系統傳送護箱暫態熱流分析”, 國立清華大學核子工程與科學研究所碩士論文, (2010).

[3] K. Kamata and K. Miyokawa, “Synthesis of Zinc Oxide Powder by Hydrolysis of BIS(Acetylacetonato)-Zinc(Ⅱ) in Aqueous Solution”, Chemitry Letters, 2021-2022 (1984).

[4] C. L. Carnes and K. J. Klabunde, “Synthesis, Isolation and Chemical Reactivity Studies of Nanocrystalline Zinc Oxide”, Langmuir 16, 3764-3772 (2000).

[5] M. Castellano and E. Matijevic, “Uniform colloidal zinc compounds of various morphologies”, Chem. of Mater., 1, 78-82 (1989).

[6] S. M. Haile and W. Johnson, “Aqueous Precipitation Spherical Zinc Oxide Powders for Varistor Applications”, J. Am. Ceram. Soc., 72, 10, 2004 (1989).