Research On Sodium-modified And Inorganic Pillared Of Bentonite

Bentonite is used as an important mineral raw material in many fields includingcasting, chemical industrial, metallurgy, food et al. In order to obtain a better applicationeffect, raw Ca-bentonite usually need be manual modified. The paper emphasizes on thestudy of the bentonite manual sodium-modified process, purification and inorganicpillaried.The Ca-bentonite clay from Anhui province was used to prepare Na-bentonite. Theblade mixer was used to improve the semi-dry method; sodium carbonate solution wasspayed in the form of fog when mixing.The optimum condition of Na-modification:Na2CO3use level was5wt%, mixing time was15min,aging time was3d by measuringthe swelling capacity and colloid index of Na-bentonite. After sodium-modification,swelling capacity was52ml/g, colloid index was55ml/g, interlayer spacing advancedfrom15.2931to13.2431.As the montmorillonite content of raw bentonite is usually low, the methods ofpurification were described and investigated.Comparing the three methods of bentonitepurification, the purity of bentonite was improved from51.04%to79.17%by highspeed centrifugation which was the optimum method. The optimum condition ofpurification: liquid-solid ratio was12,the content of sodium hexametaphosphate was0.125wt%, centrifugation speed was1200r/min, centrifugation time was10min.Inorganic pillaring bentonite is a novel research subject about the preparation ofintercalation materials applied in catalyst et al, which will take good advantage of ourbentonite resource. In the paper, Pillared bentonite was prepared from Fe(NO3)3、Na2CO3solution and referred to the synthetic method of hydroxyl aluminum pillaredbentonite. The interlayer spacing of hydroxyl iron pillared bentonite advanced from13.2431to17.9937with the synthesis condition: Na+:Fe3+=1:1,aging time was3d,size concentration was1%,Fe3+：clay=10mmol/g, pillared reacted at80℃for24h.The pillared bentonite had good thermal stability upon heating.The results study in this paper have an important theoretical significance and practicalvalue for Ca-bentonite application development.