Polyquaternium-6 (PQ6) as the water-soluble polymer was used for complexing the anion forms of tungsten (Ⅵ) before ultrafiltration. Tungsten (Ⅵ)-PQ6 complex was retained by polysulfone hollow fiber ultrafiltration membrane in the complexation-ultrafiltration process. Effects of various operating parameters such as polymer metal ratio(PMR)

pH and chloride ion concentration on permeate flux (

J

) and tungsten rejection coefficient (

R

) were investigated. The integration of four experiments including concentration

decomplexation

diafiltration and reuse of regenerated polymer was carried out. In the process of concentration

J

declines slowly and

R

is about 1 at PMR of 3 and pH of 7. Tungsten concentration in the retentate increases linearly with volume concentration factor. Tungsten is concentrated efficiently with the membrane. The concentrated retentate was used further for the decomplexation. It takes about 6 min to reach the decomplexation equilibrium at chloride ion concentration of 50 mg·L

-1

. The decomplexation percentage of tungsten (Ⅵ)-PQ6 complex reaches 56.1%. In the diafiltration process

tungsten (Ⅵ) can be extracted effectively by using 50 mg·L

-1

chloride ion solution

and the purification of the regenerated PQ6 is acceptably satisfactory. The regenerated PQ6 was used to bind tungsten (Ⅵ) at various pH values. The binding capacity of the regenerated PQ6 is close to that of fresh PQ6

and the recovery perc

entage of binding capacity is higher than 90%.