Study On Filtration Of Hematite Concentrate With Surfactant Filter Aids

In order to explore the mechanism of surfactant filter aid on hematite concentrate in two kinds of positive flotation collector system.In this paper,the effect of sodium dodecyl sulfate,sodium dodecyl benzene sulfonate,octaphenyl polyoxyethyiene-10,dioctyl sodium sulfosuccinate and cetyl trimethyl ammonium bromide on the filtration behavior of hematite concentrate in sodium oleate system and sodium dodecyl sulfonate system under different conditions was studied by filtration test.Surface potential measurement,infrared spectrum analysis,surface tension,viscosity and particle contact angle measurement were carried out to explore the mechanism of filter aid.The results of filtration test showed that the resistance of filter cake and moisture content of filter cake increased with the increase of reagent dosage in sodium oleate system.At room temperature and p H 6.8,the dosage of sodium dodecyl sulfonate is 40g/t.The results show that the water content of filter cake can be reduced by 3.93% at the concentration of 0.1%,and the p H of strong acid and strong alkali has a certain influence on the filtration process.The moisture content of filter cake increases with the increase of temperature,and the resistance of filter cake decreases with the increase of temperature;in the system of sodium dodecyl sulfonate,the resistance and water content of filter cake increase with the increase of reagent dosage.When cetyl trimethyl ammonium bromide is used at room temperature and p H is 6.8,the dosage of cetyl trimethyl ammonium bromide is 120 g/T,and the concentration of cetyl trimethyl ammonium bromide is 0.3%,the moisture content of filter cake can be reduced by2.78%,which can not effectively improve the specific resistance of filter cake.The strong alkaline p H has a certain effect on the filtration process,and the specific resistance and moisture content of filter cake decrease with the increase of temperature.The test results show that infrared spectrum and surface potential test showed that sodium oleate acted on the particle surface by chemical adsorption and sodium dodecyl sulfonate adsorbed on the particle surface by physical adsorption.With the increase of hematite surface charge,the resistance of filter cake increases,while the surface charge decreases,the resistance of filter cake decreases.The surface tension of sodium oleate system was further reduced by sodium dodecyl sulfonate,while the surface tension of sodium dodecyl sulfonate system was increased by cetyl trimethyl ammonium bromide.The effect of filter aid on the viscosity of the system is small,and the viscosity decreases with the increase of temperature.The filter aid can increase the contact angle of particle surface and reduce the moisture content of filter cake.The system reagent sodium oleate acts on the particle surface through chemical adsorption,the increase of particle surface charge leads to the enhancement of particle dispersion and the decrease of cake formation rate,thus increasing the resistance of filter cake;the filter aid sodium dodecyl sulfonate can reduce the particle surface charge,thus reducing the resistance of filter cake.Sodium dodecyl sulfonate acts on the particle surface through physical adsorption,and has weakly effect on the surface charge.Dehydration kinetics and capillary theory analysis show that the surface tension and viscosity of the solution and the contact angle of the particles affect the filtration rate of the filtration system.Due to the different effects of surfactants on them,the addition of filter aids in the sodium dodecyl sulfonate system increases the resistance of filter cake.The decrease of the moisture content of filter cake is mainly affected by the surface wetting work.The addition of filter aid increases the contact angle of particles and reduces the surface tension of solution,thus reducing the moisture content of filter cake.