Study On Foam Stability And Defoaming Of Dodecylamine Reverse Flotation Of Colloidal Phosphate Rock

Guizhou is a province with large phosphorus resources,but with the continuous development of phosphorus resources in recent years,the reserves of rich phosphorus resources are decreasing day by day,and the characteristics of"rare,complex and fine"ore are becoming more and more obvious,so a large number of medium and low grade phosphorus resources need to be developed urgently.Froth flotation are commonly used to improve the industrial ore grade,the method of twelve amine cation flotation agent flotation of phosphate rock is a kind of flotation reagents used,but in the reverse flotation process of collophane foam stabilization,which were liable to occur in late phosphorus ore concentrate processing difficulties,cause environmental pollution,increase of energy consumption,affect the production efficiency and a series of problems.Therefore,in this study,the dodecylamine reverse flotation collophanite process was simulated in the laboratory,and the foam stability evaluation device was set up to systematically study the foam stability and defoaming behavior,and the related mechanism was preliminically discussed.The main work is as follows:The effects of dodecylamine concentration,p H,temperature and inorganic ions on the foam properties of dodecylamine solution were studied,and the stability of the foam was further analyzed by surface tension measurement.The results showed that with the increase of dodecylamine concentration,the surface tension of the system decreased,and the foaming ability and stability of the solution increased.With the increase of p H value,the foaming ability and foam stability of the solution increased first and then decreased,and reached the highest value around p H=10.With the increase of temperature,the surface tension of the system decreases,the foaming ability of the solution increases,and the foam stability decreases.Al³⁺,Mg²⁺,Ca²⁺and PO₄^3-all promoted the adsorption of dodecylamine at the gas-liquid interface,and the apparent viscosity of liquid film increased,and the foaming ability and stability of solution were enhanced.In this paper,fluorapatite,quartz,dolomite and calcite,which are typical minerals in collophanite,are selected as test samples.Through foam stability test,liquid out test,contact angle measurement,Zeta potential measurement and microscopic analysis,the influence of dodecylamine concentration,p H,temperature,inorganic salt ions,mineral particle size and mass concentration on the stability of three-phase foam is systematically studied.The results showed that the surface potential and hydrophobicity of the four mineral particles increased with the increase of dodecylamine concentration.The three-phase foam stability of fluorapatite,dolomite and calcite increases with the increase of hydrophobicity of particles,while the three-phase foam stability of quartz increases first and then decreases.When the contact Angle is 90°,the foam stability of particles is the strongest.The three phase foam stability of the four mineral dispersion systems decreased with the increase of particle size and increased with the increase of particle mass concentration.With the increase of p H value,the stability of three-phase foam increases first and then decreases.With the increase of temperature,the stability of three-phase foam is enhanced.The presence of Al³⁺can significantly enhance the stability of three-phase foam in mineral dispersion system.Under the same conditions,the ability of the four mineral particles to stabilize foam is in order:calcite,dolomite,fluorapatite,quartz.The defoaming test of collophanite cationic reverse flotation foam was carried out by means of mechanical stirring and adding defoaming agent,and the defoaming mechanism was discussed by means of infrared spectrum testing,surface tension and viscosity measurement.The research shows that GPE polyether defoamer has good defoaming effect on dodecylamine reverse flotation collophane,and the optimal dosage is 600g/t.The faster the mechanical stirring speed,the better the defoaming effect.The defoaming rate can be significantly increased by combining mechanical agitation with defoaming agent.The study of defoaming mechanism shows that after adding GPE,the surface tension of pulp decreases,the liquid foam film becomes thinner and brittle,and it is easier to defoaming.With the increase of the dosage of GPE polyether defoamer,the slurry viscosity decreases,the liquid film drainage rate increases,and the foam stability decreases.Infrared spectrum test showed that the flotation performance of dodecylamine was not affected by adding defoamer.