摘要
Abstract
Secondary aluminum dross possesses a dual nature of hazardous solid waste and valuable resources.If not recycled,it not only leads to resource wastage but also environmental pollution.In response,a process of calcining secondary aluminum dross using a NaOH-Na2CO3 mixed additive was proposed to efficiently extract Al2O3.The process of calcining secondary aluminum dross in the NaOH-Na2CO3 system,as well as the effects of alkali dross ratio,mass ratio of NaOH to Na2CO3,calcination temperature,calcination time,dissolution temperature,dissolution time and liquid-to-solid ratio on the dissolution rate of Al2O3,were studied through thermodynamic analysis,TG-DSC analysis and chemical analysis.The results indicated that the construction of the NaOH-Na2CO3 mixed additive system helped to lower the eutectic point of the calcination system,promoted sufficient contact between aluminum ash and the mixed additive,reduced energy consumption and enhanced reaction efficiency.Under the conditions of m(NaOH+Na2CO3)∶m(SAD)=1.2,m(NaOH)∶m(Na2CO3)=1.5,calcination temperature of 800℃,calcination time of 60min,dissolution temperature of 80℃,dissolution time of 15min and a liquid-to-solid ratio of 15mL/g,the dissolution rate of Al2O3 can reach 92.29%.This study provided theoretical and practical guidance for the technical application of extracting Al2O3 from secondary aluminum dross using the NaOH-Na2CO3 calcination method,further improving the comprehensive utilization of secondary aluminum dross.关键词
二次铝灰/氢氧化钠/碳酸钠/焙烧/Al2O3溶出率Key words
second aluminum dross/sodium hydroxide/sodium carbonate/calcination/dissolution rate of Al2O3分类
化学化工
