The Research On The Mechanism Of Air Bubbles And Mineral Particle Flocs In Flotation System

Flocculation flotation is an effective method to recover fine-grained hematite.At present,the research on the interaction between particles and bubbles in flocculation flotation is still not deep enough.In order to better understand the collision and adhesion process of flocs and bubbles,a series of experimental research were carried out.A self-built observation system was used in the experiment.The CCD camera was used to study the collision and adhesion process of hematite flocs and bubbles.The effects of particle size,bubble size,flocs fractal dimension and flocs sedimentation distance on the collision probability were investigated.The results showed that the maximum collision probability was 80.47%,when the flocculant had a particle size of 146.43μm,a bubble diameter of 1.90 mm and the falling distance of 0.29 cm.The influence of the shape factor on the flocculation trajectory of the flocculation process is analyzed,and the variation law of the collision speed before and after the collision was obtained.It was found that there was a sharp drop in the velocity of the flocs.Since the adhesion process didn’t affect the collision,the adhesion between the flocs and the bubbles was studied under the collision optimal condition.The effects of sodium hydroxamate,dodecylamine,sodium oleate and sodium dodecylsulfate on the adhesion probability under different dosage and temperature were investigated.The results showed that the maximum adhesion probability was 72.16% when the dosage of sodium hydroxamate was 8mg/L,p H=9 and the temperature was 50℃;the maximum adhesion probability was 74.32% when the dosage of dodecylamine was 2.4mg/L,p H=8.74 and the temperature was 43℃;sodium dodecylsulfate had the highest adhesion probability of 61.43% when the dosage was 42mg/L,p H=9 and the temperature was 50℃;the sodium hydroxamate had the maximum adhesion probability of 60.41% when the dosage was 256.97mg/L,p H=10.5 and the temperature was 45℃.We can conclude that the order of the flocs and air bubbles adhesion was as follows: dodecylamine> sodium oleate> sodium dodecyl sulfate> hydroxamate.Through the study of the collision and adhesion of hematite flocs and bubbles under the condition of static flow field,the internal causes of differences in flotation efficiency were found,which provided guidance for the flocculation flotation of fine ore particles.