Study On Preparation And Flotation Performance Of A New Phosphate Collector Fatty Acid Lactic Ester

In order to improve the flotation performance of fatty acid reagents,lactic acid was used to modify cotton oil fatty acid.The conditions of reagent synthesis were determined through experiments.Finally,a new collector,cotton oil lactic acid ester was obtained.Through pure mineral experiment and mechanism analysis,the flotation performance of synthetic reagent and its interaction with mineral particles were explored.the flotation performance of synthetic reagent for actual minerals was tested by actual mineral flotation.The synthetic conditions were determined by experiments: the mass ratio of cotton oleic acid to lactic acid was 10:3,reaction temperature was 120 C,and reaction time was120 min.Infrared spectroscopy showed that the synthetic reagents had C=O and C-O-C characteristic absorption compared with raw materials.These two characteristic absorption peaks were the characteristic absorption of aliphatic carboxylic esters.Therefore,it can be determined that cotton oleic acid and lactic acid were esterified to form cotton oleic acid lactate.Pure mineral test shows that the optimum p H value for phosphate and dolomite flotation is 8-10,and the flotability of phosphate is better than dolomite under this condition,but the flotability of dolomite is better under acidic condition,which is not conducive to both flotation under strong acid or alkali conditions.For quartz flotation,only when p H is greater than 10,can the reagent has collecting ability.Calcium and magnesium generally reduce the recovery of phosphate and dolomite.The higher concentration is,the more obvious the reduction of recovery is.At the same time,the sensitivity of synthetic reagents to calcium is much weaker than magnesium.When using synthetic agent flotating quartz,calcium and magnesium will improve the recovery of quartz when dosage is less than 200mg/L,or the activation is weakened,and the activation of magnesium is much stronger than calcium.Foam analysis showed that the synthetic agent had stronger foaming properties compared with cottonseed oil soap,and had a shorter foam half-life.The surface tension test showed that the approximate CMC value of synthetic agents was 14 mg/L and the cotton oleic acid soap was 30 mg/L.It was found that the CMC value of synthetic agents was lower,which indicated that the concentration of critical micelles of synthetic agents was lower and the ability of reducing surface tension was stronger.Zeta potential measurements show that electrostatic adsorption may be dominant on the surface of phosphate under strong acidic conditions,and chemical adsorption may be dominant in alkaline conditions;chemical adsorption may be the main mode of interaction between synthetic reagents and dolomite;only weak physical adsorption between synthetic reagents and quartz.Infrared spectrum test: there are physical and chemical adsorption on the surface of phosphate rock when p H is 9-10;a certain degree of chemical adsorption existed between synthetic reagent and dolomite;and only weak physical adsorption between synthetic reagent and quartz.Adsorption heat test shows the interaction pocess between reagent and phosphate,dolomite surface is spontaneous,and it is chemical adsorption.EDS analysis shows that the synthetic reagent has adsorption effect on the surface of phosphate,dolomite and quartz.The adsorption amount of reagent on the surface of phosphate rock is the largest,followed by dolomite and quartz.It means that the reagent adsorbs on the surface of phosphate preferentially and shows high selectivity to phosphate.Under the conditions of grinding fineness-0.074 mm content accounting for 89.1%and positive flotation temperature of 20 o C,that a closed circuit process of direct flotationa roughing,a concentration and a sweeping election and reverse flotation-a roughing and a sweeping was adopted.The dosage of sodium carbonate,sodium silicate,scavenging collector,reverse flotation crude sulfuric acid,citric acid,collector and sweeping sulfuric acid are 6.0 kg/t,1.0 kg/t,0.9 kg/t,0.3 kg/t,6.0 kg/t,0.5 kg/t,0.6 kg/t and 3 kg/trespectively.The process and reagent system are described above.Closed circuit test results show that the P2O5 grade of concentrate is 31.36%,the P2O5 recovery is 84.35%,the P2O5 grade of reverse flotation tailings is 7.01%,and the P2O5 grade of direct flotation tailings is 8.72%.The synthetic reagent has the advantages of low cost,non-toxicity,non-pollution,simple and feasible synthesis process,high selectivity and collecting ability for collophanite under normal temperature conditions,also can be used as both positive flotation reagent and reverse flotation reagent.It has good application prospects.