Coarse BTO powder may be prepared by APT mild hydrogen reduction method.
APT Mild Hydrogen Reduction Method to Produce Blue Tungsten Oxide
After loaded on a boat, APT is placed in a multi tube furnace (11 tube electric furnace) and decomposed by heating. Hydrogen is injected into the furnace tube to maintain the reducing atmosphere. The decomposed gas and waste gas are ignited and burned out of the furnace tube. Phase composition of blue tungsten oxide can be adjusted by controlling hydrogen flow, reducing temperature and pushing rate of boat.
Parameter setting: Temperature area is 5; Reducing temperature is 300~450°C; The ventilation property is the best with proper NH3 content at this time.
NH3 content has a great influence on blue tungsten oxide property, it is controlled between 0.6~0.9% during producing process.
The pH value of blue tungsten oxide liquid suspension is usually at the range of 3~4. It is hexagonal structure and has fast ion exchange ability in aqueous solution.
More details, please visit:
http://www.tungsten-powder.com/Blue-Tungsten-Oxide.html
