The steps of ammonium metatungstate ion exchange method mainly include the following aspects:
Raw material preparation
Use ammonium tungstate solution or ammonium paratungstate as raw material to ensure that the quality and concentration of the raw material meet the production requirements.
Ion exchange
Use strong acid or weak acid H+ type cationic resin to exchange NH4+ ions in the solution with H+ ions on the resin under the condition of pH 3.5.
In this process, H+ ions enter the solution and NH4+ ions are adsorbed by the resin.
Digestion conversion
Digest at 98℃ for 5 hours to promote the conversion of ammonium tungstate into a stable ammonium metatungstate solution.
During the digestion process, H+ ions further react with ammonium tungstate in the solution to generate ammonium metatungstate.
Evaporation concentration
The digested ammonium metatungstate solution is evaporated and concentrated to increase the concentration of ammonium metatungstate in the solution.
Freeze crystallization or spray drying
The evaporated and concentrated ammonium metatungstate solution can be further prepared into ammonium metatungstate (AMT) crystals by freeze crystallization or spray drying.
Freeze crystallization is usually suitable for preparing products with higher purity, while spray drying is more suitable for large-scale production.
Resin regeneration
The resin saturated with NH4+ can be regenerated by hydrochloric acid solution to replace NH4+ ions with H+ ions so that the resin can be recycled. Resin regeneration is an important part of the ion exchange method, which ensures the reuse of the resin and reduces production costs.
Product testing and packaging
The quality of the prepared ammonium metatungstate product is tested to ensure that it meets the relevant standards and requirements.
The qualified products are packaged and stored for subsequent use or sale.
The ammonium metatungstate ion exchange method realizes the preparation process from ammonium tungstate raw materials to ammonium metatungstate products through ion exchange, digestion conversion, evaporation concentration, freeze crystallization or spray drying. This method has the advantages of simple operation, high product purity and environmental friendliness, and is widely used in the smelting production of ammonium metatungstate.
More details of ammonium metatungstate product, please visit website: http://ammonium-metatungstate.com/
Please contact CHINATUNGSTEN for inquiry and order of ammonium metatungstate:
Email: sales@chinatungsten.com
Tel.: 86 592 5129595
