水浸对电解铝二次铝灰中氮化物的影响研究

Research on Influence of Water Immersion on Nitrides in Secondary Aluminum Ash of Electrolytic Aluminum

为了脱除电解铝二次铝灰中的氮化物,实现二次铝灰的回收再利用,有必要探索二次铝灰中氮化物在水浸过程的转化规律。本文首先对二次铝灰进行成分分析和物相检测,查明二次铝灰中氮化物的含量和赋存状态,然后设计单因素试验,研究时间、温度、液固比和粒度等因素对二次铝灰水浸过程氮含量的影响规律,最后对水浸二次铝灰进行物相分析,探讨二次铝灰中的氮化物在水浸过程的反应机理。结果表明,在一定的温度范围内,温度对氮的转化率有促进作用;氮的转化率随着液固比的增大而增大;粒度对氮的转化率没有明显影响;90 ℃温度下,在4 h内,氮化铝的水解过程基本上达到终点;氮化铝水浸后生成氢氧化铝。

In order to remove the nitrides in the secondary aluminum ash of electrolytic aluminum and realize the recycling and reuse of the secondary aluminum ash,it is necessary to explore the transformation law of the nitrides in the secondary aluminum ash during the water immersion process.In this paper,the composition analysis and phase detection of the secondary aluminum ash are firstly carried out to find out the content and occurrence state of nitrides in the secondary aluminum ash,then a single factor experiment is designed to study the influence of time,temperature,liquid-solid ratio and particle size on the nitrogen content of the secondary aluminum ash during water leaching,finally,the phase analysis of the water immersion secondary aluminum ash is carried out to explore the reaction mechanism of the nitrides in the secondary aluminum ash during the water immersion process.The results show that,in a certain temperature range,the temperature has a promoting effect on the conversion rate of nitrogen;the nitrogen conversion rate increases with the increase of the liquid-solid ratio;particle size has no significant effect on nitrogen conversion;at 90 ℃,within 4 h,the hydrolysis process of aluminum nitride basically reaches the end point;aluminum nitride forms aluminum hydroxide after water immersion.