Textural, mineralogical and physico-chemical characterization of red clay of Tanout (Zinder-Niger) with a view to its valorization in water treatment

Abstract

This study aims to determine the textural (specific surface, pore volume and pore size) and mineralogical characteristics of Tanout red clay of Zinder region (Niger) in order to have textural data allowing its use as an adsorbent. The methodology is based on textural analyzes (adsorption of N2 at 77 K by the Brunauer-Emmett-Teller method), mineralogical (X-ray fluorescence, X-ray diffraction, thermo-gravimetric analysis, scanning electron microscopy) and physicochemical (preliminary analyses). The results obtained show that the red clay has a specific surface of 418.4 m2.g-1 and 967.7 m2.g-1 calculated according to the BET and Langmuir methods respectively and a microporous surface of 540 m2.g- 1, with pore volume varying from 0.0389 to 0.2535 cm3.g-1 and pore size varying from 0.3675 to 5.423 nm calculated according to the methods (Barrett-Joyner-Halenda, Dubinin-Radushkevich, Dubinin -A, Horvath-Kawazoe and Saito-Foley). It has slit and cylindrical micro- pores. It has a slightly neutral pH in an aqueous medium and a high cation exchange capacity with low humidity and density, and is mainly composed of SiO2 (83.2%), Al2O3 (7.04%) and Fe2O3 (3.35%) with trace elements, the main ones being: Zr (2490 ppm), Sr (310.21 ppm), Cu (310.1 ppm), V (290.1 ppm) and Zn (140ppm). It consists essentially of Montmorillonite, illite and Kaolinite with impurities such as quartz and rutile. This clay has a high degree of crystallinity. These characteristics make it a promoter material that can be used as an adsorbent.