Proper dissolution is the most overlooked factor in PAM performance. We get calls from customers saying their PAM "doesn't work" — and 80% of the time, the problem is improper dissolution, not the product itself. Here is the correct procedure.
Dissolution Requirements by PAM Type
| PAM Type | Dissolution Time | Optimal Temp | Concentration |
|---|---|---|---|
| APAM (low MW, 6-10M) | 30-45 min | 20-40°C | 0.1-0.3% |
| APAM (high MW, 15-28M) | 60-90 min | 20-40°C | 0.1-0.2% |
| CPAM (all grades) | 45-90 min | 20-40°C | 0.1-0.3% |
| NPAM | 60-90 min | 20-40°C | 0.1-0.2% |
| Emulsion PAM | 1-5 min | 10-40°C | 0.1-0.5% |
Step-by-Step Dissolution Procedure
- Prepare clean water — use tap water or process water at 20-40°C. Cold water (<15°C) slows dissolution significantly. Hot water (>50°C) degrades the polymer.
- Fill the aging tank — fill to 80% of target volume. Leave room for the powder and mixing.
- Start the mixer — set to low speed (50-100 rpm). You want a gentle vortex, not vigorous agitation. High shear breaks polymer chains and reduces molecular weight.
- Add powder slowly — sprinkle PAM powder into the vortex gradually over 5-10 minutes. Do not dump the entire bag at once — this causes lumping that never fully dissolves.
- Continue mixing — maintain gentle agitation for the full dissolution time (30-90 minutes depending on grade). The solution should become clear and slightly viscous.
- Check for lumps — after the dissolution time, inspect for undissolved lumps. If lumps remain, continue mixing for another 30 minutes. Persistent lumps indicate improper addition or water temperature issues.
- Dilute to working concentration — add remaining water to reach target concentration (0.1-0.3%). Mix gently for 5 minutes.
- Use within 24 hours — prepared PAM solution degrades over time. Prepare fresh solution daily for best performance.
Equipment Requirements
For continuous operation, you need at least two aging tanks — one dissolving while the other is in use. Minimum tank size: 1-2 hours of solution consumption.
- Tank material — stainless steel or polyethylene. Avoid carbon steel (PAM can corrode it).
- Mixer type — low-shear paddle mixer or slow-speed propeller. Avoid high-shear mixers (centrifugal pumps, turbine mixers).
- Mixer speed — 50-100 rpm. Faster breaks polymer chains.
- Dosing pump — peristaltic or diaphragm pump. Avoid centrifugal pumps for dosing — they shear the polymer.
- Piping — large diameter (50mm+), low velocity (<1 m/s). Avoid sharp bends and restrictions.
Common Mistakes and How to Fix Them
Lumping
Cause: Adding powder too fast, or adding to still water without a vortex.
Fix: Always create a vortex before adding powder. Add slowly over 5-10 minutes. If lumps form, continue mixing — most will dissolve with time.
Our our polyacrylamide products is engineered for exactly this use case, with batch-level quality control from our Zhengzhou facility.
Poor Performance Despite Correct Dosage
Cause: Incomplete dissolution. Undissolved polymer does not flocculate.
Fix: Extend dissolution time. Check water temperature. Reduce concentration (try 0.1% instead of 0.3%).
Solution Too Viscous to Pump
Cause: Concentration too high, especially for high MW grades.
Fix: Reduce concentration to 0.1% for high MW grades (15M+ Da). Use larger diameter piping and lower pump speed.
Solution Degrading Quickly
Cause: High temperature, bacterial contamination, or oxidizing agents in water.
Fix: Use fresh water. Keep solution temperature below 40°C. Add biocide if bacterial contamination is suspected. Use within 24 hours.
Slow Dissolution in Winter
Cause: Cold water (<15°C) slows polymer hydration.
Fix: Heat water to 25-35°C before dissolving. Or switch to emulsion PAM, which dissolves in 1-5 minutes regardless of temperature.
Need PAM for your treatment system?
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Emulsion PAM: Faster but Different
Emulsion PAM dissolves in 1-5 minutes because the polymer is already in a dispersed state. But it requires an inverter (surfactant) to break the emulsion and release the polymer into water.
Procedure for emulsion PAM:
- Add emulsion to water (not water to emulsion) under agitation
- Mix at medium speed (100-200 rpm) for 2-5 minutes
- The solution should become clear and viscous within 5 minutes
- Dilute to working concentration and use immediately
Emulsion PAM is more expensive per unit of active polymer but eliminates the need for aging tanks and long dissolution times. See our emulsion vs powder comparison for cost analysis.
Safety During Dissolution
PAM powder contains residual acrylamide monomer (≤0.05% in our products). Acrylamide is a neurotoxin — avoid inhalation and skin contact:
- Wear dust mask (N95 or better) when handling powder
- Wear nitrile gloves and safety glasses
- Work in ventilated area
- Wash hands thoroughly after handling
- Keep powder away from food and drinking water
Once dissolved in water at 0.1-0.3%, the solution is safe to handle with basic precautions (gloves). The acrylamide concentration in solution is extremely low (<0.15 ppm).
Need Technical Support?
If you are having dissolution problems or poor performance, contact us. We provide free technical support including video calls to diagnose issues in real time. You may also find our molecular weight guide and dosage calculation guide helpful for optimizing your system.
WhatsApp: +86 150-0381-8598 | Request a quote or sample
For more details, see our our jar test guide.
Get a Quote
Our factory in Zhengzhou produces 100,000 tons/year of PAM across 18+ grades. MOQ 500kg, delivery 7-10 days standard. Contact us for pricing and free sample:
- WhatsApp: +86 150-0381-8598
- Email: info@chinapolyacrylamide.com