Texture Characteristics of Modified and Activated Bentonite

Abstract

The method of modification and activation of bentonite of Navbahor district of the Republic of Uzbekistan is considered in the work. To obtain Fe-modified bentonite by the Zol-gel method, an aqueous suspension of bentonite (ratio of solid and liquid phases 1:10, aqueous extract of the suspension pH i 8) was left to swell at room temperature for one day, then bentonite particles were left for 3 minutes and was treated with ultrasound at a frequency of 22 Gts for good dispersion.The intercalating solution was prepared by mixing 1.0 M solutions of iron (III) chloride and sodium hydroxide ([OH -] / [Fe3 +] = 2.0) and left at room temperature for one day. After aging, the resulting ash was added dropwise to a 10% aqueous suspension of bentonite. The resulting modified bentonite was separated from the liquid phase in a Büchner funnel using a vacuum pump after 24 h, washed with distilled water until a negative reaction to chloride ions, and dried at room temperature. It was then thermally treated at 500 ℃ for 2 h. The method of obtaining Al-modified bentonite is carried out according to a similar method of obtaining Fe-modified samples.

               Differential thermal analysis was performed using a NETZSCH STA 409 PC / PG derivatography (sample weight ~ 50 mg) in the temperature range 20 to 800 ° C (heating rate 10 ° / min). X-ray phase analysis of the catalyst was performed on an Advanced D8 diffractometer (Brucker, Germany) at an angle of reflection of 2TH at 20 to 80 ° in CuKa-monochromatic radiation. Phase identification of crystalline compounds was performed using the JCPDS PDF2 X-ray powder standards database. The adsorption and texture properties of the obtained samples were evaluated by volumetric method from physical adsorption-desorption of low temperature (77 K) nitrogen in ASAP 2020 MR surface area and porosity analyzer (Micromeritics, United States). The surface morphology of the catalyst was studied using JSM-5610 LV scanning electron microscope, JEOL (Japan). On the basis of the obtained data the technological schemes of activation of natural mineral sorbents are developed.

               The purpose of the work is to modify and activate Navbahor bentonite and study the texture characteristics.