Modification Of Miyi Diatomite And Its Adsorption Properties Research For Vanadium(Ⅴ)

Baguan River slag field as a place to dump blast furnace slag dumping,in recent years,the accumulation of slag has been increasing,and the capacity of the slag field is near its limit.In the long erosion of rain,heavy metal ions in the slag pile are released into the surface waters of the mine.The study of waste residue shows that the pollution degree of vanadium in the soil and water sediments near Baguan River slag is moderate intensity pollution.Excessive amounts of vanadium will produce serious harm to people,animals and plants.Overdose of vanadium can cause an acute epidemic such as rhinitis,asthma,conjunctivitis,and even lung cancer.If an excessive amount of vanadium in plants and will limit its growth,reduced crop yields,affect plant to absorb certain nutrients,even cause plant poisoning death.In particular,the distance from the nearest house is less than 300 m,vanadium(Ⅴ)biological toxicity,which will bring serious harm to the health of nearby residents,so the governance of vanadium pollution is now urgent! In view of the panzhihua region has plenty of diatomaceous earth resources,diatomaceous earth with its unique microporous structure,larger specific surface area,there are a large number of surface and the hydrogen bonding characteristics in heavy metal pollution(especially the cationic form of heavy metal ions)in a wide range of applications.In this paper,Miyi diatomite is used as the research object to modify it properly.Compared with different modification methods,optimization of modified diatomite,applied directly to control local vanadium pollution.On the basis of finding the basic properties of the Miyi diatomite,the modification of heat treatment,the modification of hydrochloric acid,the modification of sulfuric acid and ferric acid,and the modification of nitric acid were carried out.The method of modification of nitric acid with good adsorption effect was obtained by static adsorption experiment.The XRD analysis,XRF composition analysis,SEM morphology analysis,specific surface area analysis and ICP-OES analysis were used to characterize the method.And then studied the influence factors of ferric nitrate modified diatomite adsorption,adsorption time,initial co ncentration,p H and temperature of vanadium),the ferric nitrate adsorption V(Ⅴ)modified diatomite ion adsorption mechanism has carried on the preliminary discussion,and field pilot test to verify the dynamic leaching ferric nitrate under modified diatomite to V(Ⅴ)ions has good adsorption effect.The results are as follows:(1)Miyi diatomite mainly composed of straight algae,disc algae,crown algae and small algae,the crystallization was evident and the content of SiO 2 was 71.0617wt%,followed by Al2O3(12.7096wt%),Fe2O3(3.8894wt%),K2O(1.9089wt%)and MgO(1.1524%).(2)In view of the obvious phenomenon of rice diatomite ore crystallization,400℃ heat treatment to enhance its degree of crystallization and reduce the specific surface area,it is not conducive to improve its adsorption performance.The treatment of hydrochloric acid has obviously improved its ratio of surface area to improve its adsorption effect,but the improvement is limited.(3)Compared with ferrous sulfate,ferric nitrate modified diatomite to V(Ⅴ)ions adsorption effect is much more superior.When the iron ion concentration is 0.5mol/L,the unit adsorption capacity of ferric nitrate modified diatomite to V(Ⅴ)is 5.6 times of unmodified,while the adsorption capacity of ferrous sulfate modified diatomaceous earth to V(Ⅴ)ions is only 1.7 times that of unmodified.(4)The α-Fe2O3 and α-FeOOH supported on ferric nitrate modified diatomite are obviously weakened by the characteristic diffraction intensity of SiO 2 after loading.But before the specific surface area by 17.869 m2/g sharply to 95.684 m2/g,unit of V(Ⅴ)ion adsorption quantity is 45 times that of the unmodified.(5)After 12 h,ferric nitrate modified diatomaceous earth to the adsorption of V(Ⅴ)gradually to reach adsorption equilibrium,the process is more in line with the quasi-secondary dynamics model.The results showed that chemical adsorption existed in the adsorption process and equilibrium adsorption Qe=42.23mg/g.The adsorption amount of V(Ⅴ)on the modified diatomite decreased with the increase of temperature,The adsorption characteristics are more consistent with the Langmuir isothermal equation,which absorbs the monomolecular layer.The adsorption process is spontaneous and is an exothermic reaction.At the same temperature as the V(Ⅴ)from the initial concentration of 46.35 mg/L,101.40 mg/L and 122.60 mg/L,spontaneous showed a trend of decrease.PH value of 4,the adsorption quantity of V(Ⅴ)reached the peak of 47.28 mg/g experiment.(6)With the self-developed leaching tank(diameter of 1.0 m,height 1.7.0 m,the effective volume of about 1.2 cubic meters)in the field of vanadium exceeded the pilot water test.The concentration of V(Ⅴ)ions in the treatment solution was still lower than the 50μg/L safety limit of the domestic water after the total treated water was 275 tons,and the removal rate was still higher than 50%.It is shown that ferric nitrate modified diatomite has a good effect on V(Ⅴ)in dynamic leaching.