Removal of Chromium from Unhydrolyzed Aluminum Dross

• Main Authors: Wei-Jen Chen, 陳威仁
• Other Authors: Cheng-Hsien Tsai
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/883g88

碩士 === 國立高雄應用科技大學 === 化學工程與材料工程系碩士在職專班 === 103 === Domestic aluminum waste recycling process produces a portion of scrap aluminum dross known as slag. Usually, aluminum slag is discarded after re-refining aluminum residue amounted to 30 to 50 percent. The aluminum slag is complicated components along with toxic heavy metals. The toxic substance is generated during the recycling process. However, excessive toxic substance not only pollutes the environment but also affects the body. Therefore, this study investigates how to lower the toxic substances. Arrange untreated waste aluminum dross (referred to as unhydrolyzed aluminum dross) with sodium hydroxide under normal pressure in ultrasonic vibration device reaction. Also, use the ion precipitation and lower pH value to remove the chromate. In the meanwhile produce aluminum-containing product. From this experiment process, lower pH drop value to remove silicon, add barium chloride to remove chromium, and hydrochloric acid lower the pH value to produce aluminum hydroxide precipitate containing chromium. Al Jardine aluminum dissolution rate of the sodium hydroxide is 46.2 ~ 49.4%. It could be formation of sodium aluminate solution. Chromium content of the product remain 20.7 ~ 34.8% of the total amount and aluminum slag recycling rate from 82.5% to 24.9 ~ 37.9%.