Brine treatment in chloralkali industry comprises a series of unit operations, where the impurities such as Calcium, Magnesium, Iron are eliminated before it is fed to the electrolyers. Media and precoat filters form part of the conventional brine treatment system for the removal of suspended impurities such as calcium, magnesium, iron and barium suphate escaping through the brine coming from the clarifier. The polishing filter or the precoat filter removes the suspended impurities present in the brine before it is sent to the electrolyers.

Ultrafiltration technology is best explained as a membrane technology capable of rejecting particles of size of micro level. The ultrafiltration membrane for brine application has a pore size of 0.05 microns. The ultrafiltration system replaces pre-coat filters thus providing a most efficient system in terms of particle removal, power consumption and maintenance. In the process of brine treatment, the impurities in the salt such as calcium and magnesium are transformed to insoluble impurities. Majority of the precipitated impurities will settle at the clarifier and remaining escapes in the overflow. The suspended solids in the brine overflow is trapped in a series of filter to render the brine suitable for electrolysis.