How to Optimize Flocculant Dosage in a Thickener
Increasing flocculant dosage can improve settling velocity over part of the operating range, but this does not mean underflow density or dewatering will improve indefinitely. The optimum dose is found by balancing several process outputs.
Why there is no universal optimum dose
The optimum depends on mineralogy, fines content, feed solids, pH, process water and polymer properties. The same APAM can show a different dose window when slurry conditions change.
Is settling rate enough?
No. Fast settling can occur with bulky, low-density flocs. Underflow solids, overflow turbidity and sediment compaction should also be monitored.
Typical signs of overdosing
Beyond the optimum region, polymer coverage, lower floc density or poor compaction may appear. Published tailings studies show that dosage does not affect settling velocity and underflow concentration in a simple unlimited linear way.
How to set up a practical dose sweep
Run low-medium-high dose levels on the same slurry. Hold polymer solution concentration, hydration time, mixing energy and sample temperature constant. Record the settling curve, overflow NTU and final sediment height.
Optimization with ALKAFLOC AB5023
The starting dose window for ALKAFLOC AB5023 should be set from the actual process sample. Current product/dose, feed solids, pH and target underflow density help define an efficient test matrix.