Strategy for Boosting Rock Phosphate Efficiency and Conversion into Nano Zeolite

Abstract

Present investigation aimed to convert rock phosphate ore into nano zeolite using calcination (from 200 to 700°C) for 48 hrs. and zeolitization (replacement by a zeolite mineral) processes in order to boost rock phosphate ore efficiency as a source of P2O5 even under high soil pHs. Crystallization, phases, physico-chemical characteristics and surface morphology were studied by visual techniques. Using scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS) which cleared that, the converted rock phosphate gave different shapes and sizes of crystals and distribution of its components (elements and oxides mass percentage). While TEM appears the crystals size of converted rock phosphate was found in nano size (19.7 -39.1 nm). Moreover Sterio microscopy illustrated that, after calcination and zeolitization processes, the nano zeolite converted from rock phosphate ore took different shapes with three dimension crystals growth as end of crystallization process. Whilst XRD manifested that, the dominant mineral was zeolite associated with different minerals represented by mica muscovite, montmorillonite, calcite, pyrite, alkali feldspar, plagoclase feldspar and quartz. At the same time, XRF was used to verify nano rock phosphate converted in to zeolite (heulandites type). Also the XRF analysis recorded Si/Al ratio (3.42%) of nano zeolite its properties tended to both hydrophilic and organophillic. Furthermore, DTA (differential thermal analysis) and TGA (thermo-gravimetric analysis) were used for measure percentages of water molecules attached with nano rock phosphate and its thermal stability. Therewithal, Surface area (BET) was (14.93m2/g), pore sizes distribution from 3.98 to 56.87 nm, pore volume19.96 nm and pore width 4.846 cm3 / g. It was observed that there is little change in particles density in both real and bulk densities. Finally, the highest CEC (cation exchange capacity) and lowest AEC (anion exchange capacity) values of the conversion rock phosphate were acquired. In a nutshell, our results designated for more liberate of P2O5 in available and safety form to uptake easily by cultivated crops, and construct an appropriate media for loading by beneficial microorganisms.