Synthesis Of Zeolite From Oil Shale Ash And Investigation Of Its Adsorption Performance

Oil shale,also known as oil shale,is brown mudstone China’s oil shale is rich in reserves.It is mainly used for retorting shale oil and fuel.A large amount of ash will be produced in the process during the processing.Long term stacking not only takes up a lot of lands,but also pollutes the surrounding environment.Therefore,how to efficiently utilizeoil shale ash has become an urgent environmental problem.Using oil shale ash asa substitutional raw material to synthesize zeolite can not only solve the problem of insufficient raw materials,but also reduce the production cost of synthetic zeolite.It thus realize the recycling of oil shale ash,and solve the environmental problems caused by the storage of oil shale retorting ash.The produced zeolite is used to treat wastewater containing heavy metals,which realizes the treatment of waste with waste,and reduces environmental pollution.It kills two birds with one stone,which has far-reaching social significance.Fushun oil shale retort ash was used as the raw material in this study to study the feasibility of synthesizing P-typezeolite by alkali fusion Hydrothermal Coupling Method and the influence factors.The effect of adding NaCl on the synthesis of P-type zeolite in the process of alkali fusion was explored,and the mechanism of alkali fusion reaction of oil shale ash under the action of NaOH and NaCl was analyzed.The effects of operation factors including ash alkali ratio,alkali melting temperature,hydrothermal temperature and NaCl addition amount on the synthesis of P-type zeolite were also discussed.The products were characterized and analyzed by XRD,SEM and BET.Based on the aforementioned studies,wefurther used the synthesized P-type zeolite to carry out the treatment of cobalt and lanthanum wastewater,exploring the influence of adsorbent dosage,initial concentration of metal ions in solution,initial pH value of solution,adsorption time and other factors on the adsorption performance of P-type zeolite acted as a adsorbent to treat rare earth wastewater,and subsequently determining the optimal adsorption conditions.Finally,the adsorption kinetics and mechanism of P-type zeolite were investigated through its is othermal adsorption test,and both the adsorption isotherm curve and adsorption kinetics curve were fitted.Our research resultsare shown as follows:1.It is proved that P-type zeolite can be synthesized from oil shale ash by alkali fusion combined with hydrothermal synthesis.It is found that the ash alkali ratio of shale ash to NaOH,alkali fusion temperature,hydrothermal temperature and the amount of NaCl addition have a decisive influence on the formation of P-type zeolite.2.The addition of NaCl is conducive to the synthesis of zeolite,while the increase of ash alkali ratio,alkali melting temperature and hydrothermal temperature is not conducive to the synthesis of zeolite;3.When P-type zeolite is synthesized from shale ash,only when the mass ratio of ash to alkali is less than 3:6 can P-type zeolite be formed.NaCl can only replace part of NaOH,and the amount of NaCl used must be enough to provide sufficient Na to meet the requirement for the the formation of P-type zeolite;4.The alkali melting temperature and hydrothermal temperature have significant influence on the synthesis of P-type zeolite via alkali melting hydrothermal method.The alkali melting temperature and the hydrothermal temperature are supposed tobe controlled at 500～800℃ and 100～120℃,respectively.Otherwise,P-type zeolite are not able to be formed;5.P-type zeolite can be used to treat wastewater containing rare earth metals,and the amount of adsorbent is positively correlated with the removal rate.With the increase of adsorption time,the removal rate and adsorption capacity of P-type zeolite for cobalt and lanthanum ions increased sharply at first,then slowly,and finally remained unchanged;6.The fitting results of adsorption isotherm model show that Langmuir isotherm model can better describe the adsorption of cobalt and lanthanum ions on P-type zeolite;7.The fitting results of adsorption kinetic model show that the pseudo second-order kinetic curve model can better describe the adsorption of cobalt and lanthanum ions on P-type zeolite.