Ammonium Paratungstate Produced by Evaporation Crystallization Method
Evaporation crystallization is the main method for producing ammonium paratungstate, it doesn’t need to add in reagent so there won’t be extra impurities. The crystalline process can also help to remove impurities to ensure quality of product. Its operation can be divided into partial intermittent operation and continuous operation. The applied manufacturing equipment is enamel reactor and continuous crystallizer.
澳门老永利总部Partial intermittent operation is operated in enamel reactor with mixing device. The crystallization rate can reach 90~95%. If the impurity content is strictly required, the crystallization rate can be controlled relatively lower, mother liquid density is on a higher standard.
澳门老永利总部Continuous operation is operated in continuous crystallizer. Heat ammonium tungstate solution to a certain degree, then deliver to the crystallizer and evaporation until solution reaches hypersaturated state. Then filter the hypersaturated solution by continuous filtration and mix with mother liquid. Do this process for two times and APT can be prepared. The obtained APT is of high quality, the grain size is even, the process is continuous, quality is stable, big production capacity and can recycle ammonia. But crystallization rate is usually 80~90%.