| Coal kaolinite is a kaolinite clay rock with kaolinite as the main mineral component in coal strata.It is a valuable natural resource with abundant reserves,which can be used in construction,printing and dyeing,plastics,chemical electronics,agriculture and refractory industries after exploited.However,a huge number of our coal-based kaolinite is considered as a direct disposal of tailings,not only polluting the environment,but also wasting resources.The process mineralogical analysis of coal kaolinite of Datong Tashan was carried out by means of chemical composition analysis,X-ray diffraction analysis,thermogravimetric analysis,and so on.It showed that the main ore mineral is kaolinite,and the main impurities containing silicates,iron-bearing minerals,titanium-bearing minerals and organic carbon.Amine hydrochloride(DAH)and dodecyloxyethylene ether(AC1201)were used as the collector to study the flotation regular of coal age rock and quartz.The mechanism of cationic collector and mineral surface was studied by means of chemical composition analysis,XRD,Zeta potential analysis,infrared spectrum analysis and molecular dynamics simulation.The main research work and results are as follows:The flotation tests of pure kaolinite and quartz showed that there are differences in the flotation ability of kaolinite and quartz by two kinds of cationic collectors.In the neutral condition,for the kaolinite,the collection capacity AC1201> DAH when the dosage is less than 750g/t,and DAH> AC1201 with the dosage is more than 1000g/t,while the quartz collection capacity is always AC1201> DAH.Zeta potential analysis showed that the isoelectric point of kaolinite was shifted in the positive direction,and the two kinds of cationic collector showed physical adsorption on the surface of kaolinite.The flotation regular for the minerals of two kinds of cationic collectors is similar.Under the condition of strong acidity,the flocculation ability of kaolinite strogener than quartz,but in alkaline environment,it is quartz> kaolinite.Therefore,the separation of kaolinite and quartz can be achieved by adjusting the pH value of the pulp.The results of mixed mineral flotation separation test showed that kaolinite and quartz could not be effectively separated only by changing the dosage of DAH and AC1201.The kaolinite can be separated by the positive flotation in the strong acid environment with pH = 2.Try to use sodium hexametaphosphate(SHMP)as an inhibitor to inhibite the flotation of kaolinite,and reverse flotation of quartz.In the neutral conditions,the addition of SHMP can inhibit quartz,but the selectivity of quartz and kaolinite is minimal.It can inhibite the flotation of quartz under acidic conditions with a high recovery rate of kaolinite.When the pH=2,DAH=750g/t,SHMP=2000g/t,the recovery of kaolinite was increased from 70.09% to 77.16%,and the recovery of quartz were reduced from 36.63% to 27.33%,significantly improved the grade of kaolinite concentrate.Based on the flotation test of pure minerals,the flotation separation of the actual mineral was carried out.The combination of OP4 and kerosene has the best effect on the removal of carbon from the raw ore,and the ash content of the tailings can be increased from 73% to 78%,when the dosage of the combination is 1000g/t.Reagent dosage=750g/t,for the minerals of ρ < 2.55g/cm3,the kaolinite is preferentially flushed at pH = 3,and the first is flotation of quartz at pH = 10,but cannot separate the mineral of ρ > 2.55g/cm3.In generally,the separation effect of kaolinite and quartz is poor.The adsorption process of DDA and AC1201 on kaolinite surface was studied by molecular dynamics simulation.The results showed that the binding energy between AC1201 and kaolinite surface is greater than DAH,which is match remarkably well with the experimental results. |
PDF Full Text Request