Promoting fine particle agglomeration through organic agglomeration solutions with charged atomization

Abstract

• The charged atomization technology of organic agglomeration solution was proposed and investigated. • Main influence factors and agglomeration mechanism were fully investigated. • The atomization and agglomeration performance of agglomeration solution before and after charged atomization were compared. • Charged atomization improved the agglomeration ability of organic agglomeration solution greatly. Chemical agglomeration is an effective method for agglomerating fine particles. Generally, an aqueous solution of an organic polymer is used as the agglomeration solution. However, these water-soluble polymers have high viscosity, resulting in a poor atomization effect of the solution, which significantly reduces the probability of collision between the agglomeration solution droplets and particles and further reduces the agglomeration efficiency of particles. To improve the agglomeration efficiency, the charged atomization technology of organic agglomeration solutions was proposed and investigated. The results showed that although the agglomeration effects of different organic agglomeration solutions on particles were different, the agglomeration performance improved after charged atomization. Among the four solutions obtained using the charged atomization technique, sodium carboxymethyl cellulose (CMC) and sodium alginate (SAA) showed the largest improvement in performance. Compared to the uncharged droplet, the agglomeration efficiency of fine particles increased by 53.4% for the 0.01% CMC solution under the charged droplet condition. With an increase in the mass concentration, the agglomeration efficiency of the particles increased but the change rate decreased, and this trend was more apparent after charged atomization. As the concentration increased from 0.03% to 0.1%, the change rates of the relative agglomeration efficiency of CMC before and after charged atomization were 11.2% and 2.4%, respectively. The change in droplet size is among the main reasons for the change in the agglomeration ability of an organic solution. Since the conductivity and viscosity of the solution affect the change in droplet size after charged atomization, it also has an effect on the agglomeration efficiency of the solution. The agglomeration performance of the organic agglomeration solution with high conductivity and low viscosity improved significantly after charged atomization. The particles exhibited characteristics of more compact chains and clusters after charged atomization.