Crystallization pattern of sodium carbonate decahydrate

It is possible to use sodium carbonate decahydrate for continuous crystallization. I’m not sure what your initial concentration is; when carrying out continuous crystallization, it’s important that the supersaturation level upon entry into the crystallizer not be too high – in other words, the temperature should not be lowered too much. If this is not the case, a large amount of crystals will form upon entry into the crystallizer, and these crystals will be numerous and fine, making them difficult to separate. The residence time for continuous crystallization is short, making it difficult for crystals to grow large, and separation is challenging. One possible method is to feed the crystallized slurry into a sedimentation tank, with the clear liquid overflowing and being separated from it at the top. It is important to maintain cold conditions during the sedimentation process, as this allows the crystals to grow further. Additionally, the mother liquor (in small quantities) remaining after the separation of solids is returned to the crystallizer, where the fine crystals entrained in it can grow further.

The ease of separation does not depend on the thickness of the crystals, but rather on the particle size distribution; if the particle sizes are relatively concentrated, then solid-liquid separation is easier to carry out.

Continuous crystallization and batch crystallization are merely different methods of operation; it is entirely possible to use continuous crystallization. We have carried out a project in Huai’an, Jiangsu, where the batch process was converted to a continuous crystallization process, and it is now in operation.

What is the production process for crystalline sodium carbonate?