Effects Of Anionic And Cationic Combined Collectors On Flotation And Froth Performance Of Hematite And Quartz

As the main raw material of iron and steel industry,iron ore occupies a very important position in China's economy.China is rich in iron ore reserves,but there are some difficulties in mining and recovery.As one of the main iron ores,hematite is of great significance to its development and utilization.Cationic reverse flotation process is one of the effective methods for hematite separation,but it is not adopted by most concentrators at home and abroad because of the problems of foam adhesion and difficulty in defoaming.In this paper,pure minerals of quartz and hematite are selected as the research object.Two kinds of representative cationic collectors,dodecyl amine and dodecyl trimethyl ammonium chloride,are mixed with four kinds of anionic collectors,sodium dodecyl sulfonate,sodium dodecyl benzene sulfonate,sodium oleate and sodium dodecyl sulfate.In the mixed collector system,the effects of collecting agents type,pH value,mass ratio,depressant dosage and other factors on mineral flotation behavior and foam stability were discussed.The performance of two-phase and three-phase foam under different conditions were analyzed by foaming device made in laboratory.With the help of rotating viscometer,the paper analyzed the relationship between viscosity and stability of foam from the experimental point of view.This experiment aims at decreasing the foam stability of cationic collector by means of the combination use of cationic collector and anionic collector on the basis of ensuring the floatation index,which will provide an available reference for sloving the foam problems of cationic collector flotation and for the flotation fine-grained hematite.In different collector systems,the results of pure mineral flotation of hematite and quartz show that the optimal pH value of quartz flotation are different,while the recovery of hematite is higher in neutral than in weak alkaline conditions.The recovery of quartz and hematite with different collectors reached to the highest value near neutral in the system of dodecyl trimethylammonium chloride and anionic collectors.The collector dosage test showed that with the increase of collector dosage,the recovery of quartz and hematite of different collector systems increase first and then keep the same.However,the dosage of quartz and hematite in different collector systems is different when the recovery reaches the maximum value.Under the condition of different collector systems,the mass ratio test shows that the recovery of quartz and hematite is different with different ratio,and the best ratio is 2:1.Under different collector systems,the recovery of quartz was basically not affected by the depressant,but the recovery of hematite was reduced in different degrees.Pure mineral flotation results show that when laurylamine and lauryltrimethylammonium chloride are respectively mixed with sodium dodecyl sulfonate,the flotation index is better than that of single cationic collector.On this basis,the mixed ore flotation test of quartz and hematite was carried out by using the two mixed collectors.The results show that when laurylamine and sodium dodecyl sulfonate are used together,the Fe grade of the concentrate is 47.51%and the recovery is 81.23%.The results show that the Fe grade of the concentrate is48.99% and the recovery is 87.07% when dodecyltrimethylammonium chloride and sodium dodecyl sulfonate are used together.The flotation indexes of the two collectors are better than those of single dodecylamine and single dodecyltrimethylammonium chloride,and are consistent with those of single mineral flotation.The experiments of two-phase foam properties show that under the system of dodecylamine and anionic collectors,the foaming ability of each mixed collectior is weak near the neutral pH value,while the foam stability is higher in acidic condition.These two properties of different collectors are affected by pH differently.Under the system of dodecyl trimethylammonium chloride and anionic collector,the foaming ability and foam stability of different collector show different trends with the increase of pH.With the increase of collector dosage,the foam stability basically presents a trend of gradually increasing or increasing first and then stabilizing.Combined with the conditions of better pure mineral flotation,that is,the pH value is 7,and the collector dosage is 0.05%,the dodecyl amine mix with sodium dodecyl sulfonate(mass ratio 2:1),compared with the dodecylamine as collector alone,the half-life of the foam decreased from 40 s to 11 s.Under the same conditions,the half-life of the foam decreased from40 min to 6min when the dodecyltrimethylammonium chloride was used as collector alone.Both of the two mixed collectors can alleviate the difficulty in defoaming when cationic collectors are used alone.Three-phase foam performance test results show that,except for the combination of dodecyl trimethyl ammonium chloride and sodium dodecyl sulfate,adding hematite and quartz will reduce the mixed collector foaming ability and foam stability.The rest of the mixed systems,adding hematite and quartz basically all can improve the collector foaming ability and foam stability.The higher the dosage of collector,the more obvious the effect is.The influence of quartz on the performance of collector foam is always higher than that of hematite.The relationship between the viscosity and the foam properties shows that with the increase of the dosage of collector,the viscosity increases at first and then changes little,which is consistent with the results of foam stability.It shows that viscosity is one of the main factors affecting the stability of the foam in the collector dosage test.With the increase of pH value,the viscosity shows an increasing trend,which is contrary to the result of foam stability.The results show that the viscosity is not the main factor affecting the stability of the foam in the pH test.