Study On Synthesis Of 13X Zeolites From BF Slag And Their Adsorption Performance

Blast furnace slag is the most abundant solid waste produced by steel enterprises.At the same time,as a secondary resource,its resource utilization can not only reduce the occupation of land,reduce the pollution to soil and water source,but also increase the addition of blast furnace slag value.At present,the main utilization way of blast furnace slag is to make cement,and its added value is not high enough to fully utilize the potential in blast furnace slag.As a large specific surface area,good adsorption capacity and good stability,zeolites are expensive and widely used.In this paper,the use of blast furnace slag synthesis of zeolite molecular sieve to achieve high value-added recycling of blast furnace slag,also for the preparation of zeolite to add a new way.The main research results are as follows:A two-step synthesis method was used to prepare the intermediate product silica gel.The blast furnace slag and hydrochloric acid were mixed to study the reaction time,reaction temperature,hydrochloric acid and hydrochloric acid concentration on the yield of silica gel.Analysis of experimental results found that the best preparation conditions for the silica gel reaction time 2h,the reaction temperature is 80?,the amount of hydrochloric acid 12ml/g,hydrochloric acid concentration 4mol/L,at this time the silica gel is amorphous,the silica content as high as 93%.Hydrothermal synthesis method,silica powder,sodium hydroxide solution and sodium aluminate solution as raw materials,the synthesis of 13X zeolite molecular sieve,the crystallization time,crystallization temperature,silica-alumina ratio,sodium to silicon ratio and water to sodium ratio Effect on zeolite 13X zeolite.The optimum conditions for the preparation of 13X zeolite were as follows:crystallization time was 6h,crystallization temperature was 90?,silica-alumina ratio was 2.8,sodium-silicon ratio was 2.8,water-sodium ratio was 45.The effects of adsorption conditions on the adsorption properties of 13X zeolites were investigated.The two kinetic models were compared with those of 13X zeolites for the adsorption of CO2.The experimental results show that the correlation coefficient(R2)of Avrami fractional kinetic model fitting curve is also well,so Avrami fractional kinetic model is the best model to describe the adsorption process.Through the fitting of the average adsorption amount,the optimum CO2 adsorption temperature was 40? and the optimal CO2 content was 1.The desorption temperature of 13X zeolites was determined by the weight loss-micromixer weight loss curve of 13X zeolites and the effect of heating rate on the desorption performance of zeolites was also studied.The experimental results show that the desorption temperature of 13X zeolite is 400?,and the heating rate has no effect on the desorption performance.The chemical modification of 13X zeolite with barium nitrate solution was carried out.The modification can improve the adsorption performance of zeolite,and study the influence of concentration of ion exchange solution and calcination temperature on the adsorption performance of zeolite 13X.The experimental results showed that the best ion exchange solution concentration of 0.1mol/L,the best calcination temperature of 300?,the modified 13X zeolite adsorption performance optimum.The experimental results showed that the use of blast furnace slag synthesis 13X zeolite,the experimental scheme feasible and not costly.On the one hand,it reduces the amount of blast furnace slag accumulation,realizes the refined,high value-added and harmless resource utilization of blast furnace slag,reduces the environmental pollution caused by blast furnace slag;on the other hand,it enlarges the way of preparing zeolite molecular sieve and reduces The preparation cost of zeolite molecular sieve.