Study On The Effect Of Adsorption And Settlement On Clay Minerals And Polymer Flocculants

Slime water treatment is an important part of coal preparation production.A large amount of clay minerals are entrained in the coal mining process.These mineral particles often cause the coal slurry water system to be highly stable and difficult to settle for a long time,which brings huge coal washing and water resource recycling.influences.In this paper,from the source,the adsorption and flocculation sedimentation tests of different types of polymer flocculants-polyacrylamide on kaolinite,illite,montmorillonite minerals(average particle size 3.2,3.7,2.2?m)and adsorption The effect of flocculation and sedimentation,combined with molecular dynamics simulation and characterization,was used to analyze the mechanism of adsorption,and to further clarify the microscopic mechanism of polymer flocculant,it can improve the solid-liquid separation efficiency of coal from the source,and make slime water treatment technology Rapid scientific development.The specific conclusions are as follows:(1)Polyacrylamide has obvious flocculation effect on kaolinite and illite,but it can hardly make montmorillonite particles form tiny flocs,and it also has poor settlement effect on montmorillonite suspension.After increasing the water hardness,the effect of polyacrylamide on the flocculation and sedimentation of minerals will be improved,especially the effect of montmorillonite is the most obvious.(2)Polyacrylamide with a concentration of 0?25 mg/L can reach adsorption equilibrium on the surface of clay minerals for 3 h.The adsorption rate of different types of polyacrylamide is:cationic polyacrylamide>non-ionic polyacrylamide>Anionic polyacrylamide;under deionized water conditions,the adsorption capacity of cationic polyacrylamide is higher than that of nonionic and anionic polyacrylamide;the introduction of Na⁺,Ca²⁺,Al³⁺will affect the adsorption capacity,after introducing Ca²⁺Will significantly increase the adsorption capacity of polyacrylamide,and the introduction of Al³⁺will produce a certain inhibitory effect,adding Na⁺has little effect on adsorption;and cationic polyacrylamide will promote the increase of the adsorption capacity under alkaline conditions,which is different from anionic and non-ionic polyacrylamide The adsorption law is reversed.(3)Simulation and characterization found that cationic polyacrylamide is mainly adsorbed on the surface of clay minerals through the amide group(CONH₂)and cationic functional group(N(CH₃)³⁺),while anionic polyacrylamide can only pass through the amide group functional group.(CONH₂)adsorption on the surface of clay minerals;the adsorption layer formed by anionic polyacrylamide on the mineral surface is more compact than the adsorption layer of cationic polyacrylamide;the adsorption of polyacrylamide on the surface of clay minerals belongs to the Langmiur adsorption model,and It is a physical adsorption that can be carried out spontaneously,and the hydrophilicity of the mineral surface is slightly enhanced after adsorption.