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The use of natural zeolites as precursors offers a valuable alternative in the search for new materials applied to zeolite synthesis. Each study focused on the interzeolitic conversion method plays a fundamental role in understanding the evolution from one zeolite to another. In this study, a natural zeolite containing the crystalline phases of clinoptilolite and mordenite, with HEU and MOR topologies, respectively, as per the coding assigned by the IZA, was employed as a precursor. Combined with potassium-aluminum hydroxide solutions at two different concentrations, followed by a conventional hydrothermal process with durations of 50 and 90 hours, characterization of both the precursor and resulting zeolite was performed. A conversion mechanism was proposed based on the structural similarity between the initial and target zeolites. To support these conclusions, characterization techniques such as X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectrometry, Fourier-transform infrared spectroscopy, inductively coupled plasma optical emission spectroscopy, and nitrogen adsorption were utilized. This process represents a potential pathway for the synthesis of merlinoite-type zeolites, MER.

A silver removal process was carried out on a Pb–Ag alloy through zinc powder injection of three different sizes (3.55, 44.4 and 734.8 μm) with a top submerged lance using nitrogen as carrying gas. The higher silver removal was obtained for the zinc powder size of 44.4 μm, while the lowest silver removal efficiency was attained for the smaller particle size. The AgZn phase was detected in the slag for the 44.4 and 734.8 μm particle sizes by XRD, which was in agreement with SEM-EDS analysis. Experimental behavior was explained according to the melting and residence time of the injected particles.