The invention relates to a method for producing
scorodite from a solution comprising
arsenic and
sulfuric acid without the use of a neutralizing agent, comprising the following steps: i. Subjecting a first
arsenic solution comprising
arsenic and
sulfuric acid in the form of a mixture of
arsenite ions and
arsenate ions to an oxidation treatment, oxidizing the
arsenite ions into
arsenate ions, a second arsenic solution is obtained; ii, adding a first solution containing
ferrous ions into the second arsenic solution to generate a third arsenic solution; iii. Adding a first portion of
magnetite to the third arsenic solution to adjust the
molar ratio of iron ions to
arsenate ions to 0.3-1 to generate a first arsenic
slurry; iv. Adding to the first arsenic
slurry a portion of the
scorodite slurry recycled from step viii as a
nucleation matrix for
scorodite particles, obtaining a first scorodite slurry of from 2% w / w to 15% w / w; v, heating the first scorodite slurry to 80 DEG C to 90 DEG C; vi, the first scorodite slurry is kept at the temperature of 80 DEG C to 90 DEG C for 5 h to 48 h, and second scorodite slurry is obtained; vii, conveying the second scorodite slurry to a
solid-liquid separation step to obtain third scorodite slurry and a treated solution; viii. Recycling a first portion of the third scorodite slurry to step iv; and (ix) filtering a second portion of the third scorodite slurry.