| With the mechanization of coal mining,the changes in coal quality are more complicated.The content of gangue doped in the raw coal is gradually increasing.The fine-grained minerals and water contained in the slime water during the coal washing process have a unique hydration effect,which makes it difficult to clarify the settlement,causing difficulties for coal washing.To solve this problem,this paper takes micro-nanometer quartz,kaolinite and montmorillonite as the research objects,analyzes the hydration characteristics of different minerals through relative viscosity,layer spacing,moisture status and water content,and expounds the influence of fine minerals on sedimentation dehydration,and draws the following conclusions:(1)The influence of different minerals on the sedimentation and dewatering effect of slime water: quartz,kaolinite and montmorillonite all affect the sedimentation and dewatering effect of slime water,but the degree of influence is different.The transmittance of the supernatant containing quartz,kaolinite,and montmorillonite slime water is 53.1%,16.3%,2.1%,and the filtration speed is 502.876 m / h,308.198 m / h,106.157 m / h,filter cake,respectively.The moisture content was 5.648%,5.759%,and 7.022%,respectively.According to the comprehensive settling dehydration test results,montmorillonite has the greatest influence on the slime water dehydration effect,followed by kaolinite,and quartz has the least influence.(2)Hydration characteristics of different minerals: The hydration of quartz,kaolinite and montmorillonite all change with the change of volume fraction and p H,but the degree of change is different.When the volume fraction changes,as the volume fraction increases,the filtration rate gradually decreases,the filter cake moisture gradually increases,the relative viscosity gradually increases,the hydration gradually increases,when the volume fraction is 1.0%,the three minerals The filtration speed is the smallest,the filter cake has the largest moisture,and the relative viscosity is the largest;when the p H value changes,quartz,kaolinite,and montmorillonite have the slowest filtration speed and the highest cake moisture when the p H values are 6,11,and 9,respectively.The relative viscosity is the largest.Based on the test results of the three minerals under different conditions,montmorillonite has the strongest hydration,followed by kaolinite,and quartz has the weakest hydration.(3)The effect of modified montmorillonite on the slime water sedimentation and dehydration effect: Wyoming sodium montmorillonite was used as it was to prepare mono-and divalent cation modified montmorillonite.Due to the effect of dehydration,it was found that monovalent cation montmorillonite has a greater effect on the slime water settlement and dehydration.(4)Montmorillonite hydration characteristics: Compared with Na-,K-,Ca-,Mg-,and Ba-based montmorillonite,the strength of the hydroxy stretching vibration peak and the hydroxy bending vibration peak is significantly enhanced.Li-based montmorillonite is hydrophilic Sexual action is stronger than Na,K,Ca,Mg,Ba-based montmorillonite.X-ray diffraction(XRD)analysis shows that the interlayer distance of the modified montmorillonite is proportional to the charge amount and inversely proportional to the interlayer cation radius.The interlayer distance of Li,Na,K,Ca,Mg,and Ba-based montmorillonite,the existence state and water content of water are related to the hydration and swelling of the modified montmorillonite.The stronger the hydration swelling capacity,the increased the value of the interlayer distance,the type of the water state,and the water content will increase accordingly.In the state of hydration and swelling,the order of the added value and water content of the modified montmorillonite layer is: Li-based > Na-based > K-based > Mg-based > Ca-based > Ba-based,and Li,Na,K-based montmorillonite have two kinds of water: bound water and free water.Ca,Mg,and Ba-based montmorillonite have only one kind of water. |
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