Elementary boron production by metallothermic reduction method

In addition to being the second toughest element, boron is used in many places due to its high melting temperature, high strength, high chemical resistance, semiconducting properties and excellent nuclear properties. In this thesis, two different reducing agents such as magnesium and aluminium metal powders were used in order to perform elemental boron production by successively applying mechanical alloying- metallothermic reduction-leaching process. In experimental work with both magnesium metal powders and aluminium metal powders, magnesium metal powders and aluminium metal powders were milled together with B2O3 powders in a speck mill, with a ball / powder ratio of 20/1, in accordance with stoichiometric calculations. After grinding, they were subjected to reduction treatment in an ash furnace at 1000 ° C for 60 minutes in an argon gas atmosphere. In the work with magnesium metal powders, the reduction product obtained after reduction was stirred for 6 hours at 300 ° C in 6M HCl solution. After the filtration was performed, the SEM and EDX analyzes of the filter products were examined. After 60 minutes of grinding, the EDX analysis of the solid particles remaining on the filter paper, resulted in an average of 94-97% elementary boron. Again, the EDX analysis of the same samples showed that the ratio of metallic magnesium was almost zero. When working with aluminium powders; The product obtained after the reduction was subjected to leaching at 180 oC in a 6-molar HCl solution in the hydrothermal apparatus. In the mechanical activation processes with Al powders, grinding times were different from experiments with magnesium powders, grinding to a longer holding time of 960 minutes. When the SEM and XRD images of some samples were examined after leaching, the AlB12 phase was formed. When the peak intensity values were examined, the formation of B phase was detected in samples A20, A22 and A24. The result is that the Al3BO6 phase is also formed due to the transformation in the structure. Depending on the duration of grinding, the expected Al2O3 reaction product during the process was removed from the structure together with leaching under pressure and temperature in the hydrothermal apparatus.