Study On The Aggregation And Settlement Behavior Of Lead-zinc Tailings Particles Under The Action Of Ultrasonic Pretreatment And Composite Flocculant

In order to maximize the sedimentation rate of lead-zinc tailings and ensure that the concentration of suspended solids in the clarified liquid is lower than the industrial wastewater discharge standard(100 mg/L)of the concentrator.This paper takes a lead-zinc tailings in Guangdong as the research object,discusses two inorganic flocculants polyaluminum chloride(PAC)and polyferric sulfate(PFS),two organic flocculants,cationic polyacrylamide(CPAM)and anionic polyacrylamide(APAM)Flocculation effect on lead-zinc tailings separately and after compounding;explore the effect of ultrasonic pretreatment of pulp on flocculation behavior under different ultrasonic conditions;analyze the flocculation process through mineral surface Zeta potential test,optical microscope and real-time online detection The mechanism;the main research content and conclusions of the thesis are as follows:(1)Explore the flocculation effect of inorganic flocculants PFS and PAC and two organic flocculants CPAM and APAM when added separately.The test results show that the two inorganic flocculants PFS and PAC are better than two organic flocculants CPAM in clarifying water quality.,APAM,but weak in increasing the settlement rate.(2)Explore the sedimentation effects of four composite flocculants PFS-CPAM,PAC-CPAM,PFS-APAM and PAC-APAM.The experimental results show that the best combination of compound flocculants is PFS-CPAM,inorganic components and organic components The best mass ratio is 3:7,and the best dosage is 80 g/t.At this time,the sedimentation rate of lead-zinc tailings is 7.69 mm/min,and the concentration of suspended solids is 46.5 mg/L.(3)Under the optimal compounding conditions,discuss the sedimentation effect of ultrasonic pretreatment with different acoustic energy density and different ultrasonic time.The test results show that when the best sound energy density is 0.04w/ml,the best ultrasonic time is 27 s,and the sedimentation rate reaches the maximum value at 8.11 mm/min,and the concentration of suspended solids is 48.3mg/L.(4)Under the best ultrasonic conditions,the changes in the flocculation behavior of lead-zinc tailings before and after ultrasonic were discussed.The test results showed that the ultrasonic energy density was 0.04 w/ml and the ultrasonic time was27 s.When the optimum dosage of tailings is 80g/t,after ultrasonic pretreatment,the sedimentation rate is increased from 7.69 mm/min to 8.11 mm/min.(5)The Zeta potential and sedimentation effect on the mineral surface show that the two inorganic flocculants PAC and PFS mainly promote the aggregation and sedimentation of lead-zinc tailings particles through the neutralization of positive and negative charges,while the two organic flocculants CPAM and APAM It mainly assists sedimentation through bridging.Among the four composite flocculants,PFS-CPAM has a greater impact on the surface charge of minerals.Ultrasound can reduce the absolute value of the surface charge of minerals,enhance the neutralization of adsorption and electrical properties,thereby promoting the flocculation process.;The change curve of the RBI value of the pulp shows that the appropriate ultrasonic conditions make the particles agglomerate more obviously and can promote the flocculation behavior.