Field Notes: Strong Base Anion Exchange Resin 201X7 FC

If you work in demin plants, ultrapure water, or nitrate polishing, you’ve probably heard the term Strong Base Anion. Here’s a hands-on look at Liji’s 201X7 FC—polystyrene gel matrix with quaternary ammonium groups (-N(CH3)3)—that, to be honest, behaves like a “solid alkali” workhorse in mixed-bed lines.

Made in Xingtai, Hebei (NO.2 East Jianshe Road, High-Tech Industrial Development South Zone, Wei County), this resin ships consistent and rugged. In fact, it fits right into deionization and condensate polishing where operators don’t have time for drama—just predictable kinetics and decent mechanical strength.

What it is (and why it works)

201X7 FC is a Type I Strong Base Anion exchange resin on a polystyrene–DVB gel matrix. The quaternary ammonium functional group delivers high total exchange capacity and good silica and CO2 uptake—especially handy in final polishing. Many customers say it’s forgiving across a wide pH window, which I’d agree with, within reason.

Spec	Typical 201X7 FC	Notes (≈ real-world)
Matrix / Type	PS-DVB gel, Type I quaternary ammonium	-N(CH3)3 functionality
Ionic Form (as shipped)	Cl−	Regenerate to OH− as needed
Total Capacity	≈1.3 eq/L (Cl− form)	Service capacity depends on leakage targets
Moisture Content	45–55%	Temperature can nudge this
Particle Size	16–50 mesh (≈0.3–1.2 mm)	UC ≤1.6 typical
Max Operating Temp	≈60 °C (OH− form)	Check silica targets above 40 °C

Process flow (quick, practical)

1. Materials: 201X7 FC, NaOH (regeneration), clean water, inert underdrain, FRP or steel vessel.
2. Methods: backwash to classify; slow rinse; service run; co-/counter-current regeneration with 2–4% NaOH; displacement rinse; fast rinse to conductivity setpoint.
3. Testing standards: leachate per NSF/ANSI 61 for potable use; routine QA gravimetric capacity and bead integrity; conductivity/silica leakage checks.
4. Service life: ≈3–7 years (fouling and oxidants are the usual life killers).
5. Industries: power condensate polishers, microelectronics UPW, pharma WFI pre-treatment, food & beverage deashing, municipal nitrate control.

Applications and advantages

Use Strong Base Anion resin for silica “chasing,” nitrate/sulfate removal, and mixed-bed polishing after RO. Advantages: high capacity per liter, rugged beads, and—surprisingly for a gel—steady pressure drop. I guess the key is keeping oxidants low and doing timely caustic regenerations.

Vendor snapshot (what buyers compare)

Vendor	Capacity (≈eq/L)	Certs	Lead Time	Notes
Liji 201X7 FC	≈1.3	ISO 9001; NSF/ANSI 61 (on request)	≈2–4 weeks	Good mechanical strength
Generic Type I	1.1–1.3	Varies	3–6 weeks	Price-driven
Type II Alternative	≈1.0–1.2	Varies	3–5 weeks	Lower silica affinity

Customization, test data, and feedback

Customization includes wet density targeting for bed expansion, mesh-size tuning for pressure drop, and pre-conversion to OH−. Recent QA lots showed chloride leakage ≤0.1 mg/L at 10 BV/h after regeneration with 4% NaOH (real-world use may vary). One municipal buyer reported 85–90% nitrate removal stability over six months; a fab utility team said silica stayed

A quick case pair

• Power plant condensate polisher: 201X7 FC with counter-current regen cut caustic use ≈12% and extended run length from 18 to 22 hours.
• Beverage deashing line: switch to Strong Base Anion narrowed conductivity drift and reduced fines carryover; operators liked the simpler backwash window.

Compliance pointers: For potable water applications, verify NSF/ANSI 61 certification; maintain oxidant control; and validate with site-specific pilot data before scale-up.

Authoritative references

1. NSF/ANSI 61: Drinking Water System Components—Health Effects
2. US EPA: Ion Exchange for Drinking Water Treatment
3. WHO Guidelines for Drinking-water Quality
4. ISO 9001:2015 Quality Management Systems