Synthesis of Mordenite from Borno White Clay and Assessment of its Water Softening Capacity

Abstract

This research investigates the local synthesis of mordenite from Borno white clay (BWC), aiming to create a sustainable, low-cost zeolite. The novelty of this work lies in using naturally occurring BWC—previously underutilized for zeolite production in this region—as an aluminosilicate precursor. The study's objectives include collecting, beneficiating, and characterizing BWC to assess its suitability as a zeolite precursor; synthesizing zeolite through hydrothermal crystallization; and evaluating its ion-exchange capacity for water-softening applications. BWC was initially sourced from deposits in Borno State and then calcined at 700°C to transform it into an oxide form. A concentrated sodium hydroxide solution served as the alkaline medium for hydrothermal synthesis at 150°C for 8 hours. Analytical techniques such as X-ray diffraction (XRD), energy-dispersive X-ray fluorescence (EDXRF), Brunauer–Emmett–Teller (BET) surface area analysis, density functional theory (DFT), and ion-exchange capacity (IEC) measurements were used. The results showed that the BWC mainly consists of Quartz, Muscovite, and Orthoclase. Zeolite was successfully synthesized from BWC through hydrothermal methods. XRD confirmed the crystalline formation of mordenite. EDX analysis revealed high contents of sodium, silicon (58.66%), and aluminum (14.67%), which are vital for ion-exchange functions. The BET surface area reached 509.9 m²/g, and pore analysis indicated properties suitable for adsorption and ion exchange, with a beneficial hierarchical micro-mesopore structure. Ion Exchange Capacity (IEC) testing demonstrated the effective removal of calcium ions from hard water, confirming the product’s potential for water softening.