Research On Dispersion And Flocculation Behavior And Mechanism Of Fine Hematie Particles

This paper studies several kinds of dispersant and flocculant influence the settlement rate of fineparticle hematite and quartz. Besides, the dispersion and flocculant mechanism have been studiedthrough solution chemistry calculation, infrared spectrum analysis, zeta potential measurement andextended DLVO theory potential.Different amounts of sodium polyphosphate, sodium hexametaphosphate, sodium silicate, citricacid, are added into the deionized water to measure the sedimentation rate of hematite and quartz.According to the test results, the dispersion effect of hematite is clearly better than quartz. The resultshows the order of hematite dispersion: sodium hexametaphosphate> sodium silicate> citric acid>sodium polyphosphate. Meanwhile, just adding a little sodium hexametaphosphate can keep thedispersed system steady in an alkaline condition. The best dispersed condition is10.4pH value,4mg/Lof sodium hexametaphosphate, stirring10minutes with1000r/min stirring rate. The result of the bestdispersed condition is that the dispersion rate of hematite is53.01%and quartz is24.63%. Based on thedispersion test, the settlement test has been carried out. And the best settlement condition is3mg/L ofcausticizing corn starch as flocculating agent, stirring4min with600r/min stirring rate. Under thiscondition, the sedimentation rate difference of hematite and quartz is50.81%as the largest value.Separating the artificial mixed mineral (the grade is47.01%) under the best condition of dispersion andflocculation, the grade of concentration is47.01%, the recovery of concentration is87.87%onlythrough a separation.The dispersion mechanism of sodium hexametaphosphate was studied through zeta potential testsand DLVO theory. Sodium hexametaphosphate is adsorbed on the surface of hematite which increasesthe electrostatic repulsion among the hematite particles, also it can make the particles generated strongsteric repulsion. The mechanism of corn starch on hematite and quartz is researched by infraredspectroscopy, medicament has greater influence on hematite than on quartz was been found. Themedicament is adsorbed on the mineral surface in a form of chemical adsorption. And the adsorption ofstarch on hematite was influenced by sodium hexametaphosphate.This paper mainly studies the influence factors and change rules of fine particle of hematite andquartz by discussing settlement rate and basic theory, and provides basis for the ore separation ofmicro-fine hematite.