Preparation of LaB₆ Powders via Calciothermic Reduction using Mechanochemistry and Acid Leaching

Abstract

This study reports a room temperature mechanochemical route for the synthesis of LaB 6 powders originated from related metal oxide powders as La 2 O 3 and B 2 O 3 . Ca granules and B 2 O 3 powders were respectively used as reducing agent and boron source in the experiments. This study is actually meaningful to create added value by using the native boron source of Turkey for the production of high-technology boron materials. Milling duration as the most important parameter of mechanochemistry was examined to reveal the ideal production conditions. Mechanochemically synthesized powders were subjected to selective HCl leaching in order to eliminate unwanted phases. Thermochemical software of HSC Chemistry TM program was utilized to determine the reaction probability and to estimate the predicted products. Characterization investigations were carried out by X-ray diffractometer (XRD), differential scanning calorimeter (DSC), particle size analyzer (PSA), stereomicroscope (SM), scanning electron microscope (SEM), transmission electron microscope/energy dispersive spectrometer (TEM/EDS) and atomic absorption spectrometer (AAS). Nanosized LaB 6 powders were achieved with/without an insignificant amount of Ca 3 (BO 3 ) 2 phase via mechanochemistry in a high-energy ball mill for 3 h and via leaching with 4 M and 6 M HCl. Lastly, the experimental outputs obtained by a calciothermic reduction were compared with those of magnesiothermic reduction.

Impact of Alkaline Immersion Time on Nano-Hydroxyapatite Synthesis from Broiler Eggshells with Electrochemical Method Using Constant Direct Current (CDC)

“…The calcium concentration in the eggshell was analyzed using an Atomic Absorption Spectrophotometer (AAS). In order to produce a calcium chloride solution, which is part of the electrolyte solution, the calcium oxide present in calcined eggshells reacts with hydrochloric acid [30]. The reaction is shown in Reaction (2).…”

Tribochemistry as an Alternative Synthesis Pathway

“…Mossbauer studies have also been performed on ferromagnetic materials that have high magnetization and anisotropy, such as SrFe 12 O 19 [31]. Lanthanum hexaboride, LaB 6 , is used extensively in optical systems, as a refractory material; it can be synthesized via ball milling as well, due to its precise control, room temperature processing, and its simplicity [32]. Ceramic materials maintain a role in the pharmaceutical realm as well with layered double hydroxides as capable ion-exchangers; various methods, including simple mechanochemical and mechano-hydrothermal, can be used to manufacture these materials [33].…”

Effect of sintering techniques on the microstructure and mechanical properties of niobium borides

“…The subsequent acid leaching treatment provides to remove undesired products from the mechanochemically synthesized powders and yields resultant products with high purity. Previously, different kinds of boride products were synthesized in our laboratory facilities with the same combined method [45][46][47][48].…”