Effect of water on behaviour of Na2B4O7·5H2O and Na2B4O7 in
HCl-CH3OH medium
HCl-CH3OH medium
(Mining Engineering Department, Hacettepe University, Ankara 06800, Turkey)
Abstract: The reactivity of Na2B4O7·5H2O and Na2B4O7 in non-aqueous HCl-CH3OH solvent system was investigated. The effects of H2O, CH3OH/B mole ratio and reaction time on the reaction at room temperature were examined. Experimental results show that when Na2B4O7·5H2O and Na2B4O7 are the reactants, the dissolved B2O3 contents are observed to be 98.2% and 99%, respectively, in 5 min at the CH3OH/B mole ratio of 4. The decrease of water in the reaction medium was observed to increase the crystallization of NaCl in the order of Na2B4O7>Na2B4O7·5H2O. It was also observed that the boron solution obtained after the reaction could be hydrolyzed by the addition of H3BO3. The results show that HCl-CH3OH system is a more effective solvent compared to H2SO4-CH3OH both in the reactivity and the shortened reaction time.
Key words: non-metallic ores; oxide ores; hydrometallurgy; leaching