Abstract:
The objective of this study was to investigate the preliminary treatment of aluminum dross/dust in order to reduce effects of by product gases when reacting with water (moisture content in environment). The physico-chemical characteristic of aluminum dross/dust were determined, as well as, its chemical reactions and the optimal reacting conditions in order to apply as the guideline for reactor design. The results showed that the aluminum dross/dust from the melting process of the aluminum industry contained high content of aluminum nitride (AlN), which produce the ammonia gas when react with water. The samples were then tested for their reactions by mixing with water in a batch reactor. Moreover, the effect of ratio between dross/dust to water, pH, mixing condition, temperature, surfactant (TX-100) and suspended plastic media was investigated in order to propose the optimal treatment condition. From the obtained results, the optimal reacting condition for treatment of the aluminum dross was the ratio of 1:10 to water, mixing speed at 300 rpm (velocity gradient 26 S⁻¹), suspended plastic concentration of 25 g/L, TX-100 of 0.1% by weight and temperature of 45 °C. The ammonia gas production efficiency, order of reaction and reaction rate constant (k) were 44.60%, 0.75 and 1.17 s⁻¹, respectively. Moreover, the optimal reacting condition for treatment of the aluminum dust was the ratio of 1:10 to water, mixing speed at 300 rpm (velocity gradient 26 S⁻¹), TX-100 of 0.1% by weight and temperature of 45 °C. The ammonia gas production efficiency, order of reaction and reaction rate constant (k) was 8.82%, 0.51 and 2.38 s⁻¹, respectively.