LEWATIT® CNP 85

Summary

Product identification

Lewatit® CNP 85 is a weakly acidic, gelular, acrylic-based cation exchange resin of standard bead size distribution.

General Description

• Ionic form as shipped: H⁺
• Functional group: carboxylic acid
• Matrix: crosslinked polyacrylate
• Structure: gel type beads
• Appearance: light brown, translucent

Physical and Chemical Properties

• Uniformity coefficient: max. 1.5
• Bead size: > 90 % 0.4 - 1.6 mm
• Bulk density: approx. 790 g/l (± 5 %)
• Density: approx. 1.19 g/ml
• Water retention: 47 - 53 wt. %
• Total capacity: min. 4.1 eq/l
• Volume change H⁺ → Ca²⁺: max. 12 vol. %
• Volume change H⁺ → Na⁺: max. 100 vol. %
• Stability at pH-range: 0 - 14
• Storability (product): max. 2 years
• Storability temperature range: -20 - +40 °C

Recommended Operating Conditions

• Operating temperature: max. 75 °C
• Operating pH-range: 5 - 14
• Bed depth: min. 700 mm
• Specific pressure loss (15 °C): approx. 1.3 kPa·h/m²
• Pressure loss: max. 250 kPa
• Linear velocity (operation): max. 40 m/h
• Linear velocity (backwash, 20 °C): approx. 12 - 14 m/h
• Bed expansion (20 °C, per m/h): approx. 4.5 vol. %
• Freeboard (backwash, external/intern): 60 - 80 vol. %
• Regenerant: HCl / H₂SO₄
• Co-current regeneration level: approx. 70 / 90 g/l
• Co-current regeneration concentration: approx. 3-6 / 0.5-0.8 wt. %
• Linear velocity (regeneration): approx. 5 - 20 m/h
• Linear velocity (rinsing): approx. 5 - 20 m/h
• Rinse water requirement (slow/fast): approx. 6 BV

Applications

• Dealkalization of industrial water operated with co-current systems.
• In combination with a strong acidic cation exchange resin (e.g., Lewatit® MonoPlus S 100) in a decationization unit for water demineralization.
• Removal of temporary hardness (hardness associated with alkalinity).
• As a polisher in a single bed unit downstream from a demineralization unit for the removal of cations present as hydroxides at flow rates up to 50 m/h.
• In its sodium-form for the removal/extraction of heavy metals (e.g., copper, nickel, zinc) from electroplating rinse waters at pH > 5, in the absence of calcium and complexing agents.

Additional Information & Regulations

• Safety precautions: Strong oxidants, such as nitric acid, can cause violent reactions upon contact with ion exchange resins. Observe the safety data sheet.
• Disposal: In the European Community, ion exchange resins must be disposed of according to the European waste nomenclature.
• Storage: Store ion exchange resins above the freezing point of water, under roof in dry conditions, and without direct sunlight. If frozen, allow to thaw gradually at ambient temperature before handling or use.

Disclaimer: This extraction may miss figures, footnotes, or revisions. Contractual data must match the OEM PDF revision used on the project.

Official datasheet (PDF)

Lenntech datasheet mirror