Effects Of Metal Ions On The Dispersion And Aggregation Behavior Of Phosphate Ore And Its Gangue Mineral

Phosphate rock is the main raw material of phosphorus chemical industry and an important strategic mineral resource.China is rich in phosphate rock resources,but mainly in low-grade phosphate rock,separation and enrichment is difficult.In order to promote the effective dissociation of low-grade minerals,ore grinding to finer and finer size has become a common practice.The effective dispersion of particles is a prerequisite for the flotation of fine phosphate rock.In this paper,the effects of inevitable metal ions(Ca²⁺,Mg²⁺,Fe³⁺,Al³⁺)in the pulp on the dispersion behavior of a medium-low grade phosphate rock and its gangue minerals dolomite and quartz in Guizhou were systematically studied,which provided a theoretical basis for the effective separation and enrichment of fine-grained phosphate rock.The research contents and conclusions are as follows:（1）The effects of slurry pH,stirring time and stirring speed on the dispersion and agglomeration behavior of fine-grained minerals were studied.Phosphate rock and dolomite show good dispersion in the pH range of 4-12.Under acidic conditions,the dispersion is poor.Quartz has good dispersion stability in the whole pH range.The stirring speed and time have a great influence on the dispersion behavior of phosphate rock and dolomite.After reaching a certain stirring speed and time,the particle dispersion in the slurry remains stable.Changing the stirring time and speed has little effect on the dispersion behavior of quartz.（2）After adding Ca²⁺and Mg²⁺,the dispersion behavior of phosphate rock and dolomite is consistent with that without adding metal ions.The addition of Ca²⁺and Mg²⁺will obviously destroy the dispersion behavior of minerals.With the increase of ion concentration,the inhibition of mineral dispersion is more significant.In the range of pH>10,the agglomeration behavior of phosphate rock and dolomite is significant,and the addition of Ca²⁺and Mg²⁺will promote the agglomeration behavior of quartz.（3）After adding trivalent metal ions Fe³⁺and Al³⁺,the dispersion behavior of the three minerals was significantly inhibited in the pH range of 6-10,and the greater the ion concentration,the stronger the inhibition,the more obvious the agglomeration of the particles.（4）In a certain pH range,metal ions combine with OH^-in the pulp,and attach to the surface of mineral particles in the form of hydroxyl complex and precipitation,which significantly reduces the potential barrier of interaction energy between particles and makes mineral particles agglomerate by precipitation net trapping.