The present invention relates generally to water-relates to the production step of the water absorbent polymer particles, (i) carboxylic at least partially neutralized acid group-containing, monoethylenically unsaturated monomers ( 1) and the step of preparing an aqueous monomer solution comprising at least one cross-linking agent ( 3) (Ii) be in the aqueous monomer solution comprising the steps of: selectively adding the fine particles or an aqueous salt solution of a water-absorbent polymer ( ) the step of adding at least one component of the polymerization initiator system comprises a polymerization initiator or two or more components in the aqueous monomer solution (Iv) reducing the oxygen content of the aqueous monomer solution (V) the step of filling the aqueous monomer solution to the polymerization reactor (Vi) the step of polymerizing a monomer in the aqueous monomer solution in the polymerization reactor ( ) and pulverizing the polymer gel phase and the polymer gel strand that selectively released to the outside of the polymerization reactor, thereby obtaining a polymer gel particles by ( ) drying the polymer gel particles (Ix) ppatah the dried polymer gel particles thereto fine particles can by-step to obtain a water-absorbent polymer particles (X) the number of binary ppatah - arranging the water absorbent polymer particles by size And (xi) be the ppatah are arranged in order of size - and a step of treating the surface of the water absorbent polymer particles The process step (xi) is: (x1a) mixing the particles with the aqueous crosslinking agent solution And (x2a) process step (x1a) heat the mixture in the mixing device is operated horizontally obtained in-comprising treatment, wherein the mixing apparatus is operated in the hydraulic drive is horizontal.본 발명은 일반적으로 수-흡수성 중합체 입자의 제조 공정에 관한 것으로, (i) 카르복실산기를 함유하는 적어도 부분적으로 중화된, 모노에틸렌계 불포화 단량체 (α1) 및 적어도 하나의 가교제 (α3)를 포함하는 수성 단량체 용액을 제조하는 단계 (ii) 상기 수성 단량체 용액에 수-흡수성 중합체의 미세 입자 또는 수성 염 용액을 선택적으로 첨가하는 단계 (ⅲ
