Barium Production
Barium Production
Barite concentrate (80-95% BaSO4), is the main feedstock material for barium extraction. It is obtained by barite flotation with using liquid glass as dead rock depressor. BaSO4 extraction ratio equals 55-60%. After BaSO4 reduction with lack coal, coke or natural gas BaS is obtained:
BaSO4 + 4C => BaS + 4CO;
BaSO4 + 2CH4 => BaS + 2C + 4H2O
which then is converted into other barium compounds. After roasting at 800, 1400 and 700°C BaO is produced which then is reduced with aluminium powder at 1100-1200°C:
4BaO + 2Al => 3Ba + BaO*Al2O3.
This reaction is processed in the reactor; it is the main commercial method of barrium extraction. The extraction is processed in argon atmosphere or in vacuum, which is more preferable. Mole ratio BaO:Al =(1.5-2):1. The reactor is placed into the furnace in the way which puts its "cold part" into the zone with temperature around 520°C. On the next step barium is refined via vacuum distillation achieving impurities concentration less than 10-4 mass % or 10-6% via zone melting.
Small barium quantities may be extracted reducing BaBeO2, the product of synthesis Ba(OH)2 and Be(OH)2 with titanium at 1300°C or Ba(N3)2 decomposing at 120°C after exchange reactions between barium and NaN3.