| Summary: | 碩士 === 國立中山大學 === 環境工程研究所 === 106 === Aluminum is the most abundant metallic element in the earth and it is widely used in our daily life. In aluminum manufacture process will produce secondary product like aluminum dregs and dust. It will cause air、water and soil pollution without properly stabilizing treatment. Aluminum contents around 30~50% by weight in the composition of aluminum slag and dust. If we collect aluminum secondary product as raw material for recycle, it can achieve the goal of zero waste and circular economy.
At this research, aluminum slag is providing from aluminum recycling factory. It extract alumina from aluminum slag by different sulfuric acid concentration、weight ratio of aluminum slag and sulfuric acid、sulfuric acid amount and acid leaching reaction temperature. At this research, it applied 6 experiment conditions to improv the returns-ratio and increase the alumina concentration. The experiment No.1~No.4 result indicates the alumina weight percentage of product is above 8.43%~14.59%. The sulfur trioxide (SO3) weight percentage of product is above 75.84~85.61%. It assumed Al2(SO4)3 dissolve after the aluminum slag at acid leaching reaction, the Sulphur element can’t removed after the solution dry out. The experimental No.5 and No.6, the alumina concentration is 48.27% and 64.52%, Both experiments indicate the sulfur trioxide weight percentage can be inhibit by high temperature calcination. This procedure increase the alumina weight percentage due to the impurity remove by calcination.
At experiment N0.6, it mixed the aluminum slag and sulfuric acid by weight ratio 1:10 for acid leaching reaction at room temperature. It collected the clear solution and heating to 780℃ for 2.5hours, Alumina will dissolve and the quantitative analysis result indicated the aluminum return ratio is 57.08%, the return ratio is the highest in these 6 experiments. It assumes the aluminum slag completely mixed with sulfuric acid, aluminum can be extract more efficiency due to sulfuric acid concentration and the acid leaching reaction time. It assumes the aluminum slag completely mixed with sulfuric acid, aluminum can be extract more efficiency due to sulfuric acid concentration and the acid leaching reaction time. The alumina returns-ratio is the lowest and it only reach 12.63%. It assumed this condition need longer acid leaching reaction time due to low sulfuric acid concentration.
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