%0 journal article %@ 2075-4701 %A Le, T., Pistidda, C., Puszkiel, J., Milanese, C., Garroni, S., Emmler, T., Capurso, G., Gizer, G., Klassen, T., Dornheim, M. %D 2019 %J Metals %N 10 %P 1061 %R doi:10.3390/met9101061 %T Efficient Synthesis of Alkali Borohydrides from Mechanochemical Reduction of Borates Using Magnesium–Aluminum-Based Waste %U https://doi.org/10.3390/met9101061 10 %X Lithium borohydride (LiBH4) and sodium borohydride (NaBH4) were synthesized via mechanical milling of LiBO2, and NaBO2 with Mg–Al-based waste under controlled gaseous atmosphere conditions. Following this approach, the results herein presented indicate that LiBH4 and NaBH4 can be formed with a high conversion yield starting from the anhydrous borates under 70 bar H2. Interestingly, NaBH4 can also be obtained with a high conversion yield by milling NaBO2·4H2O and Mg–Al-based waste under an argon atmosphere. Under optimized molar ratios of the starting materials and milling parameters, NaBH4 and LiBH4 were obtained with conversion ratios higher than 99.5%. Based on the collected experimental results, the influence of the milling energy and the correlation with the final yields were also discussed.