The Investigation Of Modified Methylene Blue Adsorption Equation Based On X-ray Diffration And Bentonite Purification

Montmorillonite is the main component of the bentonite.The latter is widely used in various fields.The application of the bentonite depended on the purity of montmorillonite,so the accurate content of montmorillonite is urgently determined.Currently,the montmorillonite content is calculated by methylene blue adsorption.However,the equation has defect,particularly in determination of high-purity bentonite.The fitting of Rietveld full spectrum from X-ray diffraction was employed to accurately measure the monmorillonite content.The result was satisfied,unfortunately,the operation was significantly complex and expensive.Thus,in this work,considering the fitting of Rietveld full spectrum from X-ray diffraction,the equation of methylene blue adsorption might be modified.A serial of methylene blue absorption from different bentonites was measured.The value was in comparison with the determining results from the X-ray diffraction Rietveld full spectrum.Finally,the methylene blue adsorption formula was well revised.The result showed:when the MBT<40g/100g,the methylene blue adsorption formula is:M=MBT/0.442;when MBT≥40g/100g,the equation is:M=0.0462×eMBT/8.4642+83.8176.Furthermore,the raw bentonite was purposed from the Fuxin jinshi,which was studied the purity approach and demonstrated the modified equation.It was found that wet purication was fairly effective.And the optimum conditions as follow:bentonite slurry of liquid-sold ratio optimal value is 15;selection of(NaPO3)6 as dispersant,the optimal concentration is 0.2%;the pH of bentonite slurry is 7-8;the settling time is 50min;the centuifuge speed is 1000r/min.Additionally,The montmorillonite content by using X-diffration Rietveld method to determine is 92.05%,while that by using modified methylene blue adsorption formula is 94.17%,These implied that the modified equation was fairly accurate,so that it will widely applied.The research show that the optimum codition of FuXin purified calcium bentonite sodium medified are.the best sodium-modified medium is NaF,the concentration is 3.8%,the temperature of water bath is 80℃,the reaction time is 100mim,the pH value is 8.the concusion from the experiment study,the order of the impact of the factor is pH value>sodium-modified medium concentration>sodium raction time>sodium temperature.