Chlor-Alkali (Brine Polishing)

Durco Filters Pressure Leaf filter brine polishing systems are specifically designed for pre-filtration to protect expensive ion exchange systems in chlor-alkali production.


Brine is used in the production of chlorine and caustic soda, two basic chemicals used in many industries. In Chlor-Alkali plants, brine is introduced into clarifiers. Salts are removed and the over-flow is sent to polishing filters (pressure leaf filters).  Ion exchangers are then used downstream of the polishing filters.


Ion exchange systems are very expensive to maintain and repair. Chlor-Alkali producers rely on the upstream filters to protect them. If solids bypass the polishing filters, the ion exchangers quickly become plugged and must be repaired or replaced at great expense. Also, bridging between filter leaves due to variations in the process stream is a common problem.  These Durco Filters must handle the potentially damaging effects of bridging to avoid down-time for repair. Finally, as ion exchange technology evolves there is an increasing need for sub-micron particle removal.

Pressure Leaf Brine System
Durco Filters Brine Filtration System
click here to lear more about Durco Filters Pressure Leaf Units


Durco Filters Brine Filtration Systems.

Durco Filters Caulked Filter Leaf
Durco Filters Proprietary Caulked Polypropylene Leaf
Ascension Industries meets the difficult challenges of brine filtration with the Pressure Leaf Brine Filtration Systems which feature our exclusive Caulked Filter Leaf. This proprietary polypropylene leaf resists bending, breaking and bypassing even in the most difficult brine applications. A polypropylene filter media or membrane laminate is held in place on the surface of the leaf by means of a caulked groove. This method of media attachment assures zero bypass and efficient cake discharge.

Durco Filters Technical and Filtration Data for Brine Polishing Systems

Technical Data

  Application Overflow from brine clarifiers. Polishing filters upstream of ion exchange systems.
  Equipment Custom engineered horizontal pressure leaf filter system with exclusive caulked filter leaf.
  Materials of Construction Rubber lined pressure vessel.
Polypropylene filter leaves with caulked filter media.

Filtration Data

  Liquid Clarified Brine
  Suspended Solids Magnesium hydroxide and calcium carbonate
  Attainable Flow Rates 1 Gal/min/ft²
  Cycle Length 8-24 hours typical (Dependent on overall solids concentration and ratio of magnesium hydroxide to calcium carbonate)
  Filteraid Cellulose precoat and body feed

Durco Filters Brine Filtration Systems Features and Benefits

Durco Filters Pressure Leaf Brine Polishing Systems Incorporates state-of-the art filtration technologies, providing enhanced performance in brine filtration applications.

  • Proprietary Durco Filters Caulked Filter Leaf:
      • Polypropylene Construction - Compatible with brine, the leaf resists bending and distortion from bridging
      • Polypropylene Filter Media - Eases cake discharge and encourages even cake formation
      • Exclusive Cloth Attachment Method - Caulking groove and rope eliminate bypass and permits simple, on-site replacement of filter media
      • Leak-Free Nozzle - O-Ring design eliminates by-pass and permits easy leaf replacement
  • DuraSluice™ Highly Efficient Sluice System - Alternating pulse sluicer assures thorough removal of contaminants while conserving wash fluid
  • FRP Piping - Provides corrosion resistance for lower cost
  • Titanium Internals - Offers a long service life with maximum corrosion resistance and minimal maintenance
  • Removable Filtrate Manifold - Easy field replacement
  • Fully Automated and Integrated Controls - A wide range of control options are available to match any application
  • Rubber Lined Vessel- Complete rubber lining provides superior corrosion resistance
  • Exclusive T-Section Gasket - Unique T-section gasket design prevents damage to rubber lining


The Durco Filters team has installed many successful brine filtration systems. We combine our 130+ years of continuous filtration experience with modern design, state of the art manufacturing and proprietary methodology to create the finest brine filtration systems available.

Consult Durco Filters About Your Application Needs

Consult a Durco Filters Chlor-Alkali/Brine Systems Engineer to arrange testing and analysis of your process stream and determine the optimum filtration technology for your particular operation.  You can call +1.716.693.9381, email This email address is being protected from spambots. You need JavaScript enabled to view it., or fill out one of our Filtration Fast Track Form and one of our Application Engineers will get back to you right away.

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