Patent ID: 8513378

Claim:
A method for producing water-absorbing resin powder, comprising sequentially: a polymerization step for polymerizing an aqueous solution of acrylic acid (salt) to obtain a hydrogel-like cross-linked polymer; a drying step for drying the obtained hydrogel-like cross-linked polymer to obtain a dried polymer; a pulverization step for pulverizing the obtained dried polymer with a pulverizing means to obtain a pulverized polymer; a classification step for classifying the obtained pulverized polymer to obtain a classified polymer; and a surface cross-linking step for surface cross-linking the obtained classified polymer; characterized in that, at least a part of the classified polymer is supplied again to the same or a different pulverization step, before the surface cross-linking step, wherein circulation pulverization ratio in the pulverization step, represented by the following equation is larger than 1.50: (Circulation pulverization ratio)=(total supply amount of the water-absorbing resin to the pulverization step)/(total discharge amount of the water-absorbing resin at the drying step); [EXPRESSION 1] wherein (total supply amount of the water-absorbing resin to the pulverization step)=(total discharge amount of the water-absorbing resin at the drying step)+(amount of the classified polymer supplied again to the same or different pulverization step).