How is the amount of filter aid to be added calculated?
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How much filter aid should be added per ton of alkali? Will it affect the whiteness after addition? Thank you
It depends on the active ingredients of the filter aid. In our company, the dosage of the filter aid used is around 250 g/t, which can reduce the moisture content in heavy alkalis by 2–3%; moreover, its addition has virtually no effect on brightness.
Filter aids are generally used to reduce the moisture and salt content in heavy alkalis, thereby saving water used for washing and reducing steam consumption during the calcination process. Furthermore, the filter aid improves the fluidity of the caustic soda, reducing the risk of it clogging the chute in the calcination furnace. The typical usage is calculated per ton of alkali, at around 200–250 g. This depends on the process conditions at your site. It relates to ammonia-alkali and double-alkali processes, as well as the cooling methods of carbonization towers. I hope this helps you. Feel free to contact me if you have any questions.
Adding a filter aid gives it a really bad smell. The manager insisted on using it, but it’s completely pointless – the system gets shut down right away at night. Moreover, the use of this filter aid seems to cause foaming in the carbonization tower, leading to an incorrect liquid level reading, which in turn damages the carbonization tower