Thermochemistry of triboactivated natural and NH4-exchanged clinoptilolite mixed with Tunisian apatite

Abstract Mechanical tribo- and thermo-chemical methods applied for remodeling phosphate raw materials manifest a number of advantages over the conventional technologies. They are related to the reduction of soil contamination and minimization of the released gas emissions in the environment and generate solid wastes. In this work, natural and NH4-exchanged clinoptilolite are used for increasing the transition of P2O5 into assimilated by plants form during tribochemical activation (TCA). Better nutrients assimilation as well as green production could be achieved by applying such a treatment based on the ion-exchange reactions taking place in the soil. The occurring upon TCA structural changes and phase transformations of the used Tunisian phosphorite, natural and NH4-exchanged clinoptilolite as well as their mixtures are investigated by means of X-ray powder diffraction, IR spectroscopy, and thermal analysis. The thermal method gives evidence for solid phase reactions and increased reactivity as a result o...