A Uniform Particle Size, High Capacity Cation Exchange Resin for Softening and Demineralization Applications

Product Type Matrix Functional group
DOWEX’ MARATHON” C Strong acid cation Styrene-DVB, gel Sulfonic acid
Guaranteed Sales Specifications Na+ form H+form
Total exchange capacity, min. eq/I 2.0 2 1.8
kgr/ft3 as CaCO3 43.7 39.3
Water content % 42 – 48 50 – 56
Uniformity coefficient, max. 1.1 1.1
Typical Physical and Whemical Properties Na+ form H+form
Mean particle size+ Pm 585 ±50 600 ± 50
Whole uncracked beads % 95-100 95-100
Total swelling (Na+  H+) % 8 8
Particle density g/ml 1.28 1.2
Shipping weight g/l 820 800
Ibs/ft3 51 50
Recommended Operating Conditions
Maximum operating temperature 120°C (250°F)
pH range 0-14
Bed depth, min. 800 mm (2.6 ft)
Flow rates:
Service/fast rinse 5-60 m/h (2-24 gpm/ft2)
Backwash See figure 1
Co-current regeneration/displacement rinse 1-10 m/h (0.4-4 gpm/ft2)
Counter-current regeneration/displacement rinse 5-20 m/h (2-8 gpm/ft2)
Total rinse requirement 2-5 Bed volumes
Regenerant 1-8% H2SO, 4-8% HCl or 8-12% NaCI

+ For additional particle size information, please refer to the Particle Size Distribution Cross Reference Chart (Form No. 177-/CH 171-476-E).

Typical properties and applications:

DOWEX* MARATHON* C strong acid cation exchange resin is a uniform particle size resin designed for demineralization applications. The small uniform beads exhibit faster kinetics than conventionally sized resins. The improved kinetics

results in improved regeneration efficiency, higher operating capacity, reduced regenerant usage and less waste water.

DOWEX MARATHON C resin also shows outstanding stability to compressive and osmotic stress.


25 liter bags or 5 cubic feet fiber drums.

Figure 1. Backwash Expansion Data Figure 2. Pressure Drop Data
Temperature = 25° C (77° F) Temperature = 20° C (68° F)
For other temperatures use: For other temperatures use:
FT = F77°F [1+ 0.008 (T°F -77)], where F = gpm/ft2 PT = P2o°c / (0.026 T°c + 0.48), where P – bar/m
FT = Fz5°C [1+ 0.008 (1.8T°C - 45)], where F = m/h PT = P68°F / (0.014 T°F + 0.05), where P = psi/ft

Warning: Oxidizing agents such as nitric acid attack organic ion exchange resins under certain conditions. This could lead to anything from slight resin degradation to a violent exothermic reaction (explosion). Before using strong oxidizing agents, consult sources knowledgeable in handling such materials.

Notice: No freedom from any patent owned by Seller or others is to be inferred. Because use conditions and applicable laws may differ from one location to another and may change with time, Customer is responsible for determining whether products and the information in this document are appropriate for Customer’s use and for ensuring that Customer’s workplace and disposal practices are in compliance with applicable laws and other governmental enactments. Seller assumes no obligation or liability for the information in this document. NO WARRANTIES ARE GIVEN; ALL IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY EXCLUDED.

Published September 1998.